International Zoo News Vol. 47/7 (No. 304) October/November 2000

CONTENTS

OBITUARY – Phillip Glasier
FEATURE ARTICLES
London‘s New Wetland Centre – Where Conway‘s Bullfrog Meets Zoo 2000 Malcolm Whitehead and Doug Hulyer
Parental Behaviour in a Siamang Family Group at Poznan Zoo Hanna Ferenc and Anna Wielich
The Management of Crested Porcupines at Suffolk Wildlife Park Nicholas J. Prior
Infertility in Captive Male Gorillas: A Review Don Cousins
Letter to the Editor
Conservation
Miscellany
Annual Reports
International Zoo News
Recent Articles

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OBITUARY

Phillip Glasier, 1915–2000

Phillip Glasier, who died on September 11 at the age of 84, is sometimes said to have done for birds of prey what Sir Peter Scott did for wildfowl. He founded his Falconry Centre at Newent, Gloucestershire, U.K., in 1967, and over the next 15 years enlarged the collection to include all types of raptors. Under its present name of the National Birds of Prey Centre, Newent now holds more than 90 species, including falcons, hawks, buzzards, eagles, vultures and owls. The centre‘s breeding record has always been outstanding, and it holds many British first captive breeding records. To date, 60 species in all have been bred at the centre.

Glasier came into conservation through his lifelong interest in falconry. In the early 1950s, after war service and a few years as a photographer, he moved to Scotland, where he developed his skills as a falconer. Among those who went hawking with him at this time were the actor James Robertson Justice and the naturalist and writer Gavin Maxwell. In 1963 Glasier published his first book, As the Falcon Her Bells, a popular account of hawking which became a best-seller. A few years later he moved with his family to Gloucestershire, and there, in May 1967, the Falconry Centre opened to the public, displaying 60 birds.

Within a few years, Newent was beginning to appear regularly in the International Zoo Yearbook lists of birds bred in captivity – kestrel, merlin, crested caracara, lanner falcon, goshawk, ferruginous hawk, common buzzard, red-shouldered hawk – and this at a time when birds of prey were being bred worldwide, by today‘s standards, in negligible numbers. This conservation work was complemented by the centre‘s spectacular flying displays, designed to demonstrate the different hunting characteristics of the various species.

Glasier‘s next book, Falconry and Hawking (1978), both traced the history of the craft and gave detailed practical information on breeding, rearing and training. He remained active as a _hands-on‘ falconer, teaching his skills to others, and the use of his birds in numerous television commercials developed into an unexpectedly profitable sideline. One hawk even appeared on stage in a production of Giselle at the Royal Opera House, Covent Garden.

In 1982 Glasier retired to Scotland, where falconry continued to be his favourite pastime, but he also found time to produce an autobiography, A Hawk in the Hand (1990). The National Birds of Prey Centre passed into the hands of his daughter Jemima Parry-Jones, who still runs it today.

Nicholas Gould

[In 1999, Jemima Parry-Jones was awarded an M.B.E. in the Queen‘s Birthday Honours for services to conservation.]

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LONDON‘S NEW WETLAND CENTRE – WHERE CONWAY‘S BULLFROG MEETS ZOO 2000

BY MALCOLM WHITEHEAD AND DOUG HULYER

Another day in the urban jungle

Three children enter an airport terminal. It‘s a terminal with a difference, though, because the _planes‘ are birds – a host of waterbirds alighting and departing from a rich mosaic of lakes, lagoons and reedbeds. Elsewhere, a family are using a touchscreen to book a holiday through time – a weekend in Saxon or Stone Age London, perhaps. Someone else is watching a pair of endangered New Zealand blue duck (Hymenolaimus malacorhynchos) foraging in a white-water stream. And a gaggle of school pupils have shrunk to the size of caddis flies in a thatched Neolithic-inspired building called the Pond Zone.

This is the Wetland Centre – 44 hectares [108 acres] of newly-created wetlands just four miles from Westminster in the heart of London. It‘s part reserve, part zoo, part garden, part interactive science museum and discovery centre – a celebration of the environmental and cultural aspects of wetlands, a chance for urbanites to reconnect with that all-evasive wilderness, and a slice of social activism facilitating the route from awareness to action for a sustainable future.

It all began with Sir Peter Scott.

The _vision thing‘

Peter Scott will be well-known to many I.Z.N. readers. Described as the _patron saint of conservation‘, he was instrumental in the modern conservation movement, not least for founding the Worldwide Fund for Nature (WWF), the Red Data Books and the Wildfowl and Wetlands Trust (WWT).

Peter‘s vision was simple – to bring people and wildlife together for the benefit of both. The WWT still follows this maxim, and central to its mission is the operation of nine centres throughout the U.K. All WWT centres feature wild wetland areas and most have extensive captive wildfowl collections. There is an emphasis on in situ and ex situ conservation programmes through education, research, captive breeding and protected area management. Starting with the famous Slimbridge in Gloucestershire, England, the Wetland Centre is WWT‘s ninth centre, and the first in an urban area. This time, the trick is to get the birds to visit the people rather than the other way round.

Putting it together – partnership for life

Barnes, in south-west London, was the site of four functioning Victorian water reservoirs until the late 1980s. Then, Thames Water, the public water company responsible for supplying most of London‘s water, built a ring main to carry water around the capital. The reservoirs, on Thames Water land, became redundant. There was, however, a statutory obligation to retain the site as a water body, as it had been designated a Site of Special Scientific Interest (SSSI) because of the wintering diving ducks it attracted. Enter WWT.

Peter Scott always wanted a London centre. The Barnes site provided that, so WWT and Thames Water formed a partnership dedicated to building the Wetland Centre. In an imaginative _enabling development‘, nine hectares of the site were sold to a property developer, Berkeley Homes. Eleven million pounds from resulting house sales financed the transition of reservoirs to reserve and the construction of on-site buildings. Berkeley Homes came on board as the third partner. An environmental charity, a public company and a private corporate – strange bedfellows, maybe, but it worked and it continues to work. A further five million pounds was fund-raised from corporate donors and grants for interpretation and building fit-outs.

Putting it together – reservoir to reserve

It would be five years before the first ground was broken. After the reservoirs were decommissioned in 1994, lowering of the water bodies began, and the first diggers moved onto the site in November 1995. There began a huge recycling and habitat creation project – probably the most exciting and complicated of its kind in Europe, and certainly unique in terms of its proximity to the heart of a capital city. This involved:

– The break-up of 44 hectares of concrete-edged reservoirs. The concrete was used in footpaths, to protect wetland shorelines and to make an artificial deep-water reef as a nursery ground for fish.

– The sorting and re-mixing of over 500,000 cubic metres of six different soil types. One spoil-heap was moved three times before an unexploded World War II bomb was found inside it.

– The construction of 30 different wetlands, including the planting of over 300,000 aquatic plants and 27,000 trees.

– The laying down of 600 metres of boardwalk and 3.4 kilometres of pathway.

– The building of six hides (including a two-storey and a three-storey one), 27 bridges and 27 water-control sluices.

– The building of a 2,500 square metre Peter Scott Visitor Centre and state-of -the-art interpretation throughout the site.

And so the Wetland Centre grew into an all-inclusive wildlife resort, opening to the public as a conservation centre and visitor attraction in late May 2000. A monitoring ecologist is part-funded by two English statutory bodies (English Nature and the Environment Agency) to assess species diversity on-site. Over 130 wild bird species, 24 butterflies, 260 moths, 18 dragonflies and damsel flies, four amphibians and a host of other creatures are recorded annually.

A note about the wild wetlands

Every Wetland Centre habitat is different, designed by WWT ecologists with an attention to detail that encourages and accommodates the special needs and niches of diverse wildlife. The habitats are managed seasonally to satisfy requirements of summer and winter visitors. If the 21st century zoo aspires to topping up non-functioning ecosystems with captive-bred stock, the Wetland Centre approaches the problem from the other direction by creating ecosystem form and hoping it evolves into function. Elsewhere in WWT, the Threatened Species Unit does pursue time-honoured strategies of metapopulation management as part of integrated in situ/ex situ work. Specifically created wild wetland habitats at the Centre include:

Main Lake – a large open-water body to attract wintering and moulting ducks. The islands and shoreline are designed to minimise erosion from waves, and planted to provide shelter for summering and wintering waterbirds including grebes and the nationally rare lapwing (Vanellus vanellus). Some islands are covered in shingle to encourage nesting by little ringed plovers (Charadrius dubius). Deep water trenches prevent reeds and other plants from invading the lake and clogging it up.

Wildside – a zone of specially created ponds and pools to attract native water plant communities, amphibians and dragonflies. The zone includes frog hibernacula that resemble Iron Age barrows and dragonfly basking rocks.

Reedbeds – four reedbeds provide important sanctuaries for a host of species including summering warblers and reed bunting (Emberiza schoeniclus) as well as mechanically and microbially filtering water that flows through the site.

Reservoir Lagoon – a deep-water lake with artificial fish reefs to attract diving ducks and other fish-eating birds including grey heron (Ardea cinerea) and cormorant (Phalacrocorax carbo). Also includes islands.

Sheltered Lagoon – like the Main Lake, but with sheltered areas preferred by breeding, roosting and moulting wildfowl.

Grazing Marsh – a washland meadow that can be flooded in winter so that grass seeds float to the surface and supply food for dabbling ducks and wigeon (Anas penelope). The marsh is drained in spring to provide nesting sites for wading birds.

Wader Scrape – an area flooded in winter with water levels lowered in spring and summer to expose large areas of organically-rich mud for probing waders to feed in.

World Wetlands – the captive area

Several hectares on the western side of the Wetland Centre are designed as a global safari through various international wetland habitats. This exhibit area – World Wetlands – features appropriate plantings and rockwork in each habitat, together with representative wildfowl from each region. Signs of life are hidden throughout for visitors to find, and a bevy of graphics/touchscreens provide interpretation. The habitats are:

Frozen North – incorporating Siberia, Spitsbergen (Svalbard) and Iceland, with species including barnacle goose (Branta leucopsis), red-breasted goose (B. ruficollis), eider (Somateria mollissima), long-tailed duck (Clangula hyemalis), whooper and Bewick‘s swans (Cygnus cygnus and C. bewickii) and Barrow‘s goldeneye (Bucephala islandica). Signs of life include discarded reindeer antlers, mammoth tusks and a snowy owl nest.

Northern Forests – incorporating pools in northern Eurasian boreal pine forests with smew (Mergus albellus) and goldeneye (Bucephala clangula), and similar pools in North American broad-leaved forests with Carolina duck (Aix sponsa), bufflehead (B. albeola) and hooded merganser (Mergus cucullatus). The signs of life are respectively black woodpecker (Dryocopus martius) tree holes and tree stumps with acid rain damage; and beaver/otter tracks. A beaver trapper‘s lodge also features wetland products and artefacts from around the world, with a touchscreen highlighting a wetland product _supermarket sweep‘.

Warm and Tropical Wetlands – incorporating south-west Asian reed swamp with white-headed duck (Oxyura leucocephala), marbled teal (Marmaronetta angustirostris) and ferruginous duck (Aythya nyroca); African floodplains with white-faced whistling duck (Dendrocygna viduata) and white-backed duck (Thalassornis l. leuconotus); South American Pantanal with species including coscoroba swan (Coscoroba coscoroba) and comb duck (Sarkidiornis melanotus); East Asian rice paddy with mandarin duck (Aix galericulata) and Baikal teal (Anas formosa), and Sumatran peat swamp forest featuring white-winged wood duck (Cairina scutulata). The signs of life range from giant Rafflesia plants and tiger tracks in Sumatra to Amazonian waterlilies (Victoria amazonica) in South America and aestivating lungfish (Protopterus aethiops), hippo tracks and flamingo nests in Africa.

Islands – incorporating Hawaii featuring Hawaiian goose or nene (how could you have a WWT centre without Branta sandvicensis?) and Laysan duck (Anas laysanensis); Australia with magpie goose (Anseranas semipalmata), black swan (Cygnus atratus), plumed whistling duck (Dendrocygna eytoni) and freckled duck (Stictonetta naevosa); Falklands and South Georgia with greater Magellan goose (Chloephaga leucoptera), black-necked swan (Cygnus melanocoryphus) and South Georgia pintail (Anas georgica); and New Zealand white water with the aforementioned blue duck. Signs of life include a splendid _rotting‘ seal corpse in Falklands (which wild pintail and penguins apparently scavenge on); estuarine crocodiles and platypus holes in Australia, and a prosaic, fabricated dog turd (oh, all right then, Canis familiaris) in Hawaii. Nice.

Other exhibit areas

The main building complex in the Wetland Centre is the Peter Scott Visitor Centre, 2,500 square metres of buildings centred around a courtyard. The buildings include an entrance/orientation/shop complex; a café and function room; an art gallery; a tower with aerial viewing; a theatre with a 12-minute running multimedia programme about water, wetlands, waterlife and WWT; and a Discovery Centre with walk-through immersion habitats downstairs and interactives upstairs, including opportunities to radiotrack water voles (Arvicola terrestris – it should be said that the voles are _virtual‘ ones), follow swallows (Hirundo rustica) through migration from Africa to the U.K. using sounds and stethoscopes, identify Bewick swans by bill pattern, build birds, see the world through the eyes of species from dragonflies to four-eyed fish (Anableps sp.) and examine a host of CD-ROMs and websites in the cyberswamp.

The showcase of the Visitor Centre and a real _wow‘ factor is the huge Observatory with massive glass frontage affording a panoramic view of the entire site and the London skyline. Because the centre is under the capital‘s main flight path, the Observatory is designed as a bird airport terminal – an avian Heathrow. Touchscreens tell about arrivals and departures, and the analogies continue through customs and passport control.

Further interpretive areas include:

Pond Zone – the Neolithic-inspired, thatched round house with TV microscopes, interactives about basic ecology and huge models of pond life. Outside are regular and raised ponds for daily pond dipping sessions during the season.

Wetland Living – a country cottage featuring historical and contemporary artefacts associated with wetland livelihoods in the U.K.

Duck Tales – a _farm-yard‘ bordered with a Cotswold drystone wall and housing domestic wildfowl.

Sustainable Gardens – three gardens created by leading designers, each reflecting different aspects of _green‘ gardening, plus an exhibit highlighting what people can do in their own gardens to save water and encourage wildlife.

Plants and Water – a trail emphasising plant adaptations to life around water and ecological succession.

Hides – with murals, graphics and CCTV. One hide, the Peacock Tower, is three storeys tall with a lift for wheelchair access.

How to exhibit a common frog – a post-modern fable for zoo people

In a riveting seminal paper some 30 years ago, William Conway took zoos to task for their lack of imagination. One solution was to take a common species – the American bullfrog – and build an entire exhibit around it, an exhibit encompassing all aspects of natural and cultural history that would give visitors _a new intellectual reference point, meaningful and aesthetically compelling; a view of another sensory and social world; a feeling of personal interest in diminishing wild creatures and collective responsibility for their future which is so closely linked to that of man. Zoos must be natural history and conservation centres for the future‘ (Conway, 1973).

The Wetland Centre is not a zoo although it has zoo elements. Couple Conway‘s vision with Peter Scott‘s, and you come close to the Environmental Resource Centre envisaged by George Rabb, in his diagram printed on page 5 of the World Zoo Conservation Strategy (IUDZG/CBSG, 1993), as the culmination of the evolution of zoos in the 21st century.

This is the state that the Wetland Centre aspires to. Conceived as a learning rather than a teaching environment, its ethos is built around three sets of five secrets – those of wetlands (they store, filter and calm water, produce many products and are home to much biodiversity), ecology (energy, cycles, conditions, communities, change) and sustainability (reduce, reuse, recycle, recreate and renew). The secrets are also the bedrock of the WWT education programme – WISE UP 11 Wetlands – which will form the focus of a future I.Z.N. article.

References

Conway, W.G. (1973): How to exhibit a bullfrog: a bed-time story for zoo men. International Zoo Yearbook 13: 221–226.

IUDZG/CBSG (IUCN/SSC) (1993): The World Zoo Conservation Strategy: the Role of the Zoos and Aquaria of the World in Global Conservation. Chicago Zoological Society, Illinois, U.S.A.

Malcolm Whitehead, Education/Visitor Services Manager, WWT, The Wetland Centre, Queen Elizabeth‘s Walk, Barnes, London SW13 9WT, U.K.; Doug Hulyer, WWT Conservation Programmes and Development Director, WWT Slimbridge, Gloucestershire GL2 7BT, U.K.

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PARENTAL BEHAVIOUR IN A SIAMANG FAMILY GROUP AT POZNAN ZOO

BY HANNA FERENC AND ANNA WIELICH

Introduction

The siamang gibbon (Hylobates syndactylus Raffles, 1821) is one of 11 (Geissmann, 1995) representatives of the Hylobatidae family, and leads a diurnal and arboreal life in the tropical rainforests of Sumatra and the southern part of the Malay Peninsula. Siamangs are monogamous animals who form family groups consisting of three to five members, namely an adult male and female and their offspring (Orgeldinger, 1991). Young animals leave the group after becoming sexually mature at the age of about six years (Orgeldinger, 1991). Each group maintains a stable social organisation that can be described in terms of a number of social behaviours (Palombit, 1994). Under natural conditions siamangs occupy a territory which is defended vocally (Marshall and Marshall, 1976; Chivers and Gittins, 1978; Gittins, 1980).

The present study was carried out on a siamang family group at Poznan Zoological Garden, Poland, from 18.10.96 to 24.06.97. The group investigated included four individuals, an adult pair and their offspring – a six-year-old (subadult) female and a two-year-old (juvenile) male.

The objective of the research was to define the pattern of siamang parental behaviour under zoo conditions, investigating whether any differences exist (a) between the mother and the father in their social relations with their offspring, and (b) in the behaviour both parents display towards the subadult female and the juvenile male respectively.

Methods

The basic method of observation was _All occurrences of some behaviours‘ (110 hours), supplemented by data from _Focal animal sampling‘ (120 hours) (Altmann, 1974). The total observation time was 230 hours. The observations were conducted in one-hour samples and the beginning of each sample was randomly chosen. Only daily activity was noticed.

Both social and non-social behaviour was investigated. In the social behaviour category special interest was focused on the parental behaviour described by the following terms: food sharing, social grooming (cleansing of vermin, licking, combing with fingers), body contact (touching, cuddling), keeping company (resting together, following other animal), playing together (chasing, wrestling, swinging). Results were worked out in _Microsoft Excel‘ and compared by test T.

Results

The total number of observed events of parental care displayed towards offspring is shown in Table 1.

Table 1. Total number of parental care behaviours displayed by parents towards both offspring noticed during 110 hours of observations by _All occurrences of some behaviour‘ method.

Behaviour categories mother father total

Food sharing 74 107 181

Playing together 129 109 238

Social grooming 128 142 270

Body contact 17 18 35

Keeping company 30 34 64

Total 378 410 788

None of the observed parental care behaviour categories was preferred or neglected by mother or father (Fig. 1). The differences between the mother and the father in the amount of noticed food sharing, body contacts, social grooming, playing together and keeping company were statistically insignificant (p= 0.1087, p = 0.6407, p = 0.5964, p = 0.5692, p = 0.8787 respectively).

Figure 1. Percentage of mother and father parental behaviour.

On the other hand, the parents appeared to be more active in taking care of the juvenile male than of his older sister, as was revealed by more intensive food sharing (90% of all events of sharing food with offspring) and playing together (63% of all events of playing with offspring). Differences in frequency of these two behaviours were statistically significant (p = 9.6 ´ 10-30, p = 0.004 respectively). In the remaining three categories of parental behaviour – social grooming, body contacts and keeping company – differences in the frequency were statistically insignificant (p = 0.366, p = 0.885, p = 0.716 respectively) (Fig. 2).

Figure 2. Percentage of parental behaviour displayed towards juvenile male and subadult female.

Events of aggressive behaviour displayed by the parents were statistically more frequent towards the subadult female (f = 1.7 per hour) than the juvenile male (f = 0.6 per hour), and 90% of these events were connected with provocation to social playing. Of all the aggressive postures and acts of aggression displayed by the adults, 74% were directed at the maturing female (p = 2 ´ 10-7).

Discussion

This study of a siamang family group in zoological garden conditions shows that both parents are engaged in parental care to the same extent (Fig. 1). This result is linked to the species‘ natural monogamous mating system that entails co-domination (Orgeldinger, 1991) and the sharing of more or less the same amount of parental duties by mother and father (Palombit, 1994). Monogamous males do not spend their energy on mating with as many females as possible, but instead invest in bringing up their offspring (Stephen and Lewis, 1977).

The initiation of paternal care usually takes place a few months after the birth, and from this moment the father is intensively involved in parental care, as has been confirmed by other biology researchers in zoos, e.g. Orgeldinger (1991). According to his zoo studies the offspring is passed on to the father at the average age of eight to ten months, or even earlier, as in Dresden Zoo where the age was two months. In families where there are two or more immature animals, the mother invariably spends the night with the younger child and the father with the older one (Orgeldinger, 1991).

On the other hand, there are some significant differences between the frequency of parental care and aggressive behaviour received by the subadult and juvenile animals in the investigated group. The younger offspring appeared to be more often given food and joined for play than the elder one (Fig. 2). Moreover, in spite of more frequent social contacts (especially social playing, which was usually followed by warning postures), he received a significantly smaller number of aggressive signals from his parents than the subadult, almost sexually mature, female. Similar results were obtained by Orgeldinger from other siamang family groups living in zoos (1991). The occurrence of increased aggression towards sexually maturing offspring seems to be in accordance with the natural behaviour pattern whereby such an animal is invariably excluded from the group and has to look for its own territory and sexual partner to establish a new family (Aldrich-Blake and Chivers, 1973; Palombit, 1994).

At Poznan Zoo the subadult female received significantly less parental care and more aggression was displayed towards her. This fact, and the more and more frequent attempts at copulating displayed by the father towards his daughter, made the zoo staff decide to separate the maturing female from the rest of the family members to avoid inbreeding, as recommended by Orgeldinger (1991).

Frequencies of the remaining parental care behaviours – social grooming, body contacts and keeping company – were not significantly different, so it is likely that in the investigated group parental care of the young female still occurred, suggesting that very strong family ties had developed. On the other hand, as the subadult female approached sexual maturity she became a source of considerable stress, so that some aspects of parental care became limited and there was an increase in the frequency of agonistic relations.

Conclusion

This study of siamang parental behaviour conducted under the unnatural conditions of a zoological garden showed that the sex of a parent did not influence the frequency of parental–offspring relations in the categories of behaviour mentioned above, which is typical for a monogamous breeding system. On the other hand, the age of the offspring seemed to be an important factor which determined the intensity of parental care (playing together and food sharing) and of agonistic behaviour.

References

Aldrich-Blake, F.P.G., and Chivers, D.J. (1973): On the genesis of a group of siamang. American Journal of Physical Anthropology 38: 631–636.

Altmann, J. (1974): Observational study of behaviour: sampling methods. Behaviour 49: 227–267.

Chivers, D.J., and Gittins, S.P. (1978): Diagnostic features of gibbon species. International Zoo Yearbook 18: 157–164.

Geissmann, T. (1995): Gibbon systematics and species identification. International Zoo News 42 (8): 467–501.

Gittins, S.P. (1980): Territorial behaviour in the agile gibbon. International Journal of Primatology 1 (4): 381–399.

Marshall, J.T., and Marshall, E.R. (1976): Gibbons and their territorial songs. Science 193: 235–237.

Orgeldinger, M. (1991): Siamangs (Hylobates syndactylus) in captivity: an overview. International Zoo News 38 (6): 5–15.

Palombit, R.A. (1994): Dynamic pair bonds in hylobatids: implications regarding monogamous social system. Behaviour 128: 65–101.

Stephen, T.E., and Lewis, W.O. (1977): Ecology, sexual selection and the evolution of mating systems. Science 4,300: 215–223.

Hanna Ferenc and Anna Wielich, Department of Animal Morphology, Adam Mickiewicz University, Szamarzewskiego 91, 60–569 Poznan, Poland. (E-mail: hania@man.poznan.pl)

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THE MANAGEMENT OF CRESTED PORCUPINES AT SUFFOLK WILDLIFE PARK

BY NICHOLAS J. PRIOR

The Old World porcupines of the family Hystricidae comprise three living genera and 11 species; the eight species of the genus Hystrix are divided into three subgenera (Nowak, 1999). The Old World porcupines commonly kept in British zoos are those of the subgenus Hystrix – the crested porcupines. This subgenus contains three species, whose natural ranges are as follows (Nowak, 1999):

H. indica – Asia Minor and the Arabian peninsula to Kazakhstan and India, Sri Lanka;

H. cristata – Italy, Sicily, possibly the Balkans, the Mediterranean coast of Africa to northern Congo and Tanzania;

H. africaeaustralis – Southern half of Africa.

Crested porcupines have a head–body length of 600–900 mm, tail length of 80–170 mm and weigh from 10 to 30 kg. Coarse dark brown or black bristles cover the head, neck, shoulders, limbs and underside of the body. The head, nape and back are covered with long quills which can be raised into a crest. The sides and back half of the body are covered with stout, cylindrical quills which can sometimes be as long as 350 mm. The subgenus Hystrix has more developed rattle quills and a shorter tail than other subgenera.

Porcupines are found in various types of habitat such as forest (of all types), plantations, mountain steppes and deserts. They may shelter in caves, rock crevices and aardvark holes, but can also dig burrows for themselves. Roots, bulbs, fruit and berries makes up the basis of the wild diet. African porcupines are also reportedly able to feed on plants known to be poisonous to cattle (Macdonald, 1984). In captivity they are fed on a variety of fruit and vegetables, plus bread and concentrated feed.

Length of gestation varies between species, with 112 days recorded for cristata, 93–94 days for africaeaustralis and 90 days for indica. The size of the litters can be between one and four, though it is usually no more than three. Porcupines generally have one or two litters a year, but it is possible for a female to have as many as three. A captive individual of H. brachyura (subgenus Acanthion) apparently holds the longevity record for the order Rodentia, having lived for 27 years and 3 months (Jones, 1982). In the wild they can live for 12–15 years.

As mentioned above, most Old World porcupines in British zoos are crested porcupines – especially specimens of H. cristata and H. africaeaustralis. In 1997 the Federation of Zoological Gardens‘ mammal inventory showed 22 collections in the U.K. holding specimens of H. cristata, H. africaeaustralis or H. indica, numbering over 60 individuals in all.

Suffolk Wildlife Park currently holds specimens of H. cristata (although I suspect that many collections could well be holding hybrid individuals). In December 1999 Suffolk had eight (2.2.3) in their group – not all the animals have been sexed yet.

The park was taken over by Banham Zoo in 1991, and the present porcupine enclosure was built in 1996. There are still a few enclosures reminiscent of the old park remaining to be upgraded and redesigned, although many others – including the porcupine exhibit – have now been rebuilt and designed to reflect the park‘s ongoing scheme to create enclosures that not only look aesthetically pleasing to the public, but also offer the animals a chance to express their full range of natural behavior – including much digging and gnawing! The old enclosure was a bare concrete rectangle with only a few logs as furnishing, which measured approximately 3.65 ´ 7.3 m, although a 0.91 ´ 1.53 m sand pit was added during the enclosure‘s last couple of years to give the porcupines a chance to dig. The house was a 0.91 ´ 1.83 m brick hut, with a tin roof which could be lifted for cleaning. The barrier was made up of asbestos sheets with a mesh overhang.

The present, new enclosure offers the porcupines a more natural and varied habitat and substrates in the outside part, and a larger, more secure and warmer house which is also a lot easier to clean. The outside has two substrates – bark chippings and sand – both several inches deep, so the porcupines have a substantial depth for digging (which they regularly do). Several tree stumps and large logs provide gnawing and climbing opportunities. Log piles allow the keepers to scatter food amongst the branches, keeping the porcupines occupied for lengthy periods as they forage for it. One of the first things people notice about the enclosure is how low the barriers are – both the public and porcupine barriers are only 61 cm high. To prevent the animals escaping, however, a strand of electric wire (about 2000 volts) runs around the top of the porcupine barrier, out of sight behind sandstone rocks. The dimensions of the enclosure are as follows: back wall – 7.93 m; right side – 11.58 m; left side – 10.54 m; front of enclosure – 8.67 m. There is a space 1.35 m wide between the public and porcupine barriers, which is planted out with shrubs such as cotoneaster, Jerusalem sage (Phlomis), Mexican orange blossom (Choisya), aucuba, euonymus and hebe. Virginia creeper (Parthenocissus) grows along the back wall of the enclosure. The enclosure has also been under-wired to prevent the porcupines from burrowing out; this also limits how far down they can burrow, to prevent their damaging the enclosure in any way.

The house is brick-built and is 2.75 m high and 3.05 m wide. When it was built tiles were fixed on the floor and the bottom half of the walls to make cleaning easier; it was found, however, that the porcupines gnawed the tiles, pulling them off the wall, even though forms of enrichment were provided when they were locked in at night. After observing the problem, it was decided to remove the tiles and replace them with stainless steel sheets on the bottom half of the wall. There have since been no problems and the sheets have not been damaged. A straw bed covers half the floor, with a small metal water dish by the drainage point in the corner.

Freshly-cut branches are put in the house every few days to occupy the porcupines when they are locked in at night. The animals are fed twice daily, in mid-morning and afternoon; unless the weather is bad, they are fed outside in the morning and in the house in the afternoon. The present daily diet is as follows (as at April 1999, for a group of seven adults):

Apple – 2 kg;

Cabbage – 1 kg (one whole);

Banana – 2 kg;

Lettuce – one whole;

Carrot – 2 kg;

Bread – 1 loaf.

1 kg of oranges is given once a week.

Also fed when available are tomato, potato, cucumber, celery, coconut, eggs, pear, grapes, grapefruit, melon, cauliflower, broccoli, avocado, courgette, pineapple and sweet pepper (capsicum).

The food is cut up into chunks, as porcupines are able to hold food with their forepaws, although food is sometimes given whole to present them with more of a challenge, e.g. cabbage or coconut. Bones are provided on occasion to give them something to gnaw and to keep their teeth trimmed – in the wild porcupines have been known to gnaw the bones of carcasses. Browse is supplied throughout the day, and the species given are hawthorn (Crataegus monogyna), blackthorn (Prunus spinosa), sycamore (Acer pseudoplatanus) and willow (Salix fragilis, S. viminalis), which are available in large quantities around the park. Other collections have also fed beech (Fagus sylvatica), maple (Acer campestre), elm (Ulmus glabra) and poplar (Populus spp.).

Porcupine breeding at Suffolk, in both the old and present enclosures, has been a regular but somewhat problematical affair on the whole. In the old enclosure there were many births, but many of the kittens were found dead (and in some cases partially eaten, although it is not known whether the kittens were cannibalized at birth, or whether they died from natural causes and were then eaten by the adults). Several kittens, however, did reach adulthood in the old enclosure and are still within the group, and the survival rate has slowly, but steadily, improved since the porcupines were moved to the new enclosure.

An overall view of porcupine breeding in British zoos, however, shows that it is on the whole not as successful as, perhaps, it should be, considering how well represented they are in collections. Nevertheless there are one or two zoos (Dudley is one example) which seem to do well with breeding their porcupines.

There is no heating system in our porcupine house, though there is an extractor fan which removes any condensation. Apart from the kittens who were found dead, there have been no health problems with any of the porcupines at Suffolk. A curious accident occurred recently at Suffolk. When one of the kittens was being restrained by hand to be sexed, and was held by the scruff of its neck, the band of skin and hair around the neck came loose and pulled off in one piece. Fortunately, after a while, the injury granulated and healed without resulting in any infection. But since this incident, when the animals need to be restrained for sexing or other reasons, we now hold them in a crate with a mesh floor.

References

Jones, M.L. (1982): Longevity of captive mammals. Der Zoologische Garten 52: 113–138.

Macdonald, D. (1984): The Encyclopedia of Mammals. Equinox, Oxford, U.K.

Nowak, R.M. (1999): Walker‘s Mammals of the World (6th edition). Johns Hopkins University Press, Baltimore and London.

Acknowledgements

I am grateful to the members of staff at Suffolk Wildlife Park who assisted with this article.

Nicholas J. Prior, Suffolk Wildlife Park, Kessingland, Lowestoft, Suffolk NR33 7SL, U.K.

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INFERTILITY IN CAPTIVE MALE GORILLAS: A REVIEW

BY DON COUSINS

This article is dedicated by the author to the memory of John Aspinall.

Introduction

Past post-mortems on captive adult male gorillas have shown a disturbing prevalence of testicular atrophy (Koch, 1937; McKenney et al., 1944; Steiner et al., 1955; Antonius et al., 1971; Dixson et al., 1980; Jones et al., 1980). In these reports the external genitalia are described as small or immature, a condition that we now recognise as characteristic of gorillas generally.

Jones et al. (1980) predicted that testicular dysfunction among captive gorillas may be more common than generally realised. This was supported by a survey conducted by Beck (1982). This study revealed that 50% of 26 gorillas tested for sterility by electroejaculation (a process in which a rectal probe with electrodes connected to a stimular is inserted into the anaesthetised gorilla and electrically stimulates him to ejaculate) in American collections proved to be infertile or suspect. Age seems to have been of little significance, as those designated sterile had an estimated age range of 10–26 years, with a mean of 16.8 years, and the fertile animals a range of 8–27 years, with a mean of 17.6 years. Copulatory behaviour also did not appear to be affected, as some infertile males copulated and some fertile males did not.

Infertility is a complex subject, and before discussing the problems in captive gorillas it is useful to gain a brief insight into the testicular and spermatozoal morphologies of this great ape.

Testicular morphology

The gorilla‘s penis has been described as being short, black, conical and flattened laterally (Hill and Harrison-Matthews, 1949): the average length is a mere three to four cm. Correspondingly small, the testes possess little storage space for the spermatozoa. Samson, the breeding male at Bristol Zoo, had testes measuring 38 ´ 18 mm and 35 ´ 22 mm, (Short, 1979), while London Zoo‘s large adult male, Guy, had testes measuring 27 ´ 18 mm and 28 ´ 18 mm (Dixson et al., 1980).

At first sight, testicular biopsies of captive gorillas suggest dysfunction: the seminiferous tubules are small in diameter, few in number, and separated by masses of interstitial Leydig cells and collagen, with little room for the spermatozoa. There is evidence that the collagen builds up with the advancing age of the animal, and Platz et al. (1979) suggested that the Leydig cells, which are responsible for testosterone secretion, may have been inhibited by large amounts of collagen in the intercellular spaces, causing infertility. However, biopsies on wild gorillas tend to refute this as the morphology described above appears to be characteristic of the species (Graffikin, 1949; Hall-Craggs, 1962; Hosokawa and Kamiya, 1962; Wislocki, 1942). Schultz (1939) observed that in primates generally small testes, relative to body size, contain a much smaller amount of tubules and a much larger amount of connective tissue than relatively large testes.

It is significant that the testes of both wild and captive gorillas contain a preponderance of interstitial cells that seem to take precedence over the spermatozoa. As the function of these cells is to promote the production of accessory sexual features, such as sexual dimorphism, it is clear that size is of paramount importance in the evolution of the male gorilla. Its testicular morphology implies that emphasis has been placed on size and strength, with reproductive potential taking a back seat, the obvious conclusion being that the animal is adapted for combat to gain access to females and to protect them and any progeny from other males and from predators. Such finely tuned reproductive morphology would clearly be vulnerable to the wide variety of adverse external forces to which captive animals are often subjected, and it is not difficult to comprehend how easily this delicate balance could be disrupted.

Spermatozoal morphology

Of all the great apes the semen morphology of the gorilla aligns most closely to that of man, and gorillas, with humans, have the highest percentage of abnormal spermatozoa (Afzelius, 1981). According to Seuanez et al. (1977), abnormal sperm in the gorilla accounts for 29%, while the values in the chimpanzee, the bonobo and the orang-utan amount to 1.5%, 4.5% and 2% respectively. These authors compared the spermatozoa in man and the great apes and found it to be a useful taxonomic guide: the gorilla semen morphology was closest to man, chimpanzee spermatozoa was very different from that of man and gorilla, but identical to that of the bonobo, while the orang-utan was morphologically distinct from the other species.

Abnormality of the spermatids does not necessarily result in infertility in the gorilla, although a count of 50% or more abnormal spermatids has been linked with sterility in other animals (Platz et al., 1980). Gorilla sperm samples with oligospermia or with 90% abnormal sperm were obtained from males who subsequently proved fertile, although it is not known if the ejaculate that proved fertile was of the same quality as the ejaculate measured in the test (Gould, 1983). Fertile males have even demonstrated low or zero motility (Gould and Kling, 1982).

Platz et al. (1979) electroejaculated five gorillas ranging in age from 8.5 to 22 years and a siamang gibbon (Hylobates syndactylus), and sperm morphology in all these animals revealed a very high percentage (68% to 97%) of abnormal heads. Testicular biopsy of two of the gorillas indicated either a prior or chronic orchitis. Nevertheless, sperm counts in three of the gorillas proved to be greater than that of a proven male gorilla at the Yerkes Primate Research Center, although motility of sperm was much higher (33%) in the Yerkes animal.

Most fertility clinics class immotile spermatozoa as dead, but in some cases they may be merely paralysed or immotile. With the aid of vital staining it has been possible to differentiate between dead and paralysed spermatozoa (Afzelius, 1981).

A gorilla semen evaluation carried out by Platz et al. (1980) presented the following results, which are not absolute: volume, ranging from about 0.5 ml to 7.0 (?) ml; colour usually milky white to grey-white; percent motility from 2% to 50%; progressive motility from 2.5 to 5.0, based on 5.0 being rapid forward movement; viscosity usually watery or slightly viscous, with occasional coagulum present in various amounts; sperm count from 3.8 million to 750 million total count; abnormal morphology from 52% to 97% abnormal.

While the mean volume of the ejaculate of the gorilla is unexpectedly small, the sperm density in the liquid portion of the ejaculate is relatively high (171 ´ 106/ml). In man the normal volume of the ejaculate is 2.5–6.0 ml, with a sperm density of 60 ´ 106/ml; in the orang-utan it is 0.2–3.2 ml, with a sperm density of 61 ´ 106/ml; and in the chimpanzee the volume is 0.1–2.5 ml and the mean sperm density is 548 ´ 106/ml (Short, 1979).

The most significant factor distinguishing the captive and wild gorillas examined is that all of the wild apes showed clear signs of spermatogenesis.

Theoretical causes of infertility in captive male gorillas

Hypotheses regarding the causes of infertility in captive male gorillas are many and varied: stress and deficiency in vitamin E (Böer, 1983); deficiencies in B-complex vitamins and vitamin E (Steiner et al., 1955); obesity (Platz, 1987); overheating of testes due to the gorilla‘s anatomy and artificial heating in zoo ape accommodation (Foster and Rowley, 1982; Gould in Dittrich, 1983); toxicosis from pesticides (Foster and Rowley, 1982); inadequate sexual development due to lack of social and sexual stimulation (Böer in Dittrich, 1983); congenital conditions (Platz et al., 1980). In addition, some diseases can cause pathological conditions in the generative organs, including hepatitis A, hepatitis B, cytomegalovirus, herpes hominis Type 1 and Type 2, Epstein–Barr virus, rubella, myxovirus (mumps), measles, influenza, polio, Coxsackie virus, echovirus, lymphocytic choriomeningitis, Brucella, Salmonella, Mycobacterium, Corynebacterium, Pasteurella, Escherichia, Proteus, Staphylococcus, Candida, Trichomonas, Mycoplasma and Chlamydia (Keeling, 1982; Satterfield and O‘Rourke, 1982). At least two captive animals have developed Leydig cell tumours (Jones et al., 1980; Karesh et al., 1988).

Given the gorilla‘s emotional profile, it is logical to conclude that the ape is susceptible to even minor stress situations. Anxiety and stress have been shown to have a substantial impact on spermatogenesis in man and domestic animals, and can also cause disruption of ovarian activity in humans. The condition is reported to disturb the pituitary function, and may prove a prime candidate in those perplexing cases where a gorilla sires one or two infants before lapsing into spermatogenic arrest. Gould (in Dittrich, 1983) believes that the gonadotrophins could be an indicator of stress in gorillas – if levels are low stress is a fact, if high stress may be excluded.

Some of the essential vitamins and minerals may have a direct influence on fertility, and serious deficiencies could affect reproduction. The subject is a complex and under-researched one, while the work that has been carried out can be contradictory. The daily recommended intake of vitamin C (ascorbic acid) for adult humans, for example, ranges from 30 mg to 80 mg, according to which researcher you listen to. Deficiencies in ascorbic acid are said to cause a marked increase in the likelihood of genetic damage to the sperm, the vitamin appearing to encourage the growth of the plasma testosterone level. In laboratory tests, 36 doctors taking less than 200 mg of vitamin C daily had three times lower testosterone levels than 52 doctors taking more than 200 mg of the vitamin a day (Cheraskin et al., 1983).

Irreversible atrophy of the testes due to vitamin E (tocopherol) deficiency has been demonstrated in rodents and pigs. The stimulating effect of vitamin E on the synthesis of gonadotrophins and its depressing effect on oxygen consumption in the tissues was absent in these cases. Experimentally induced tocopherol deficiency has led to degeneration of testicular tissue in bull calves, but additive doses enhanced fertility in adult bulls as a result of an increased amount of sperm and more frequent sexual activity. When given a diet without vitamin E, male rats developed testicles that weighed one-third of the control specimen testicles. Under similar conditions degenerated epithelium was found in the seminiferous tubules of rats.

Low levels of vitamin A in experimental rats and cattle have interfered with reproduction, the animals either totally failing to reproduce, or achieving pregnancy but with few live births resulting. Vitamin B5 (pantothenic acid) has demonstrated sexual enhancement, while vitamin D3 has been seen to play an important role in the breeding performance of captive primates.

Zinc enhances and maintains testosterone levels. It has also been found to inhibit the action of 5-alpha-reductose, an enzyme facilitating the conversion of testosterone into the less useful and possibly harmful dihydrosteron. The mineral is considered an essential ingredient in the formation and motility of the sperm. Humans with serious zinc deficiencies produce almost no sperm whatsoever, while low levels can result in reduced sexual interest and, in some cases, impotence.

Selenium, another important mineral, works specifically with vitamin E and has similar health-giving effects. It is situated primarily in the sex glands, and is lost in ejaculation. Plant foods of wild gorillas in Campo Reserve, Cameroon, have moderately high levels of zinc, and moderately low levels of selenium in comparison to other minerals (Calvert, 1985). High levels of both zinc and selenium can be toxic.

Gorillas are known to frequent certain stretches of beaches on the Atlantic seaboard, particularly in the Petite Loango Reserve in south-western Gabon (P.H. Chanjou, pers. comm.). It is interesting to speculate whether the apes search for shellfish, which are rich in mineral content, including zinc and selenium. It is known that mandrills in Gabon eat freshwater fish, crabs and prawns, the remains having been found associated with their tracks on river banks (Jouventin, 1975).

Poor diet and inactivity can and do promote obesity in captive gorillas, which can ultimately lead to complications. In early post-mortems on adult males exhibiting testicular atrophy, the animals were invariably very large (see Table 1), which may or may not be coincidental. Gould (in Dittrich, 1983) cites two cases of splendid adult male gorillas in U.S. zoos, each weighing about 200 kg, who were diagnosed as having spermatogenic arrest, with no sperm being recovered by electroejaculation or found to be present on testicular biopsy. Both animals copulated, although no maturation of sperm could be detected. After a change of environment and a loss of about 50 kg in weight over an 18-month period, both became spermatogenic, one siring an offspring. Whether it was the loss of weight, the change of environment, or a combination of both (or even perhaps some other factor/s) that brought about this change could not be determined.

The possibility of obesity being the sole direct agent of infertility is debatable: wild mountain and lowland adult males can develop huge bellies. However, excessive weight can help to generate excessive heat. It is not difficult to imagine how the scrotal temperature would rise when the tiny genitalia are trapped between the huge bulk of the animal and the floor when it sits around on its haunches. These floors, too, are often heated. The amount of heat generated could easily damage the spermatozoa.

The absorption of toxic material has caused minor problems in the past, principally from lead ingestion (Fisher, 1954). Saturnism (lead poisoning) is believed to cause sterility, and the adult male Gust, who lived at Antwerp Zoo, was thought to be impotent for this very reason (De Bisschop, pers. comm.); but lead-based paint is now rarely, if ever, used and the dangers from the element are well known. The modern equivalent is pesticides, which are sprayed near display areas. Foster and Rowley (1982) support the need for further investigation into insecticides as a potential danger, but as far as I am aware no intensive research has yet been undertaken.

The theory of retarded sexual development through a lack of social and sexual stimulation is a valid one that can be applied particularly to those individuals who are reared or kept alone for many years before being given access to a female or females. Captive gorillas raised in well-planned social groups, with ample living space, successful activity programmes, and a varied diet often have prolific breeding records (Howletts in Kent, U.K., is a prime example).

Platz et al. (1980) give details of a 8.5-year-old wild-caught male gorilla at Houston Zoo who was observed to mate repeatedly with two females, but failure to conceive, and the absence of any history of illness or injury during the animal‘s captive life, prompted investigations. Two semen collections and analysis revealed 92.5% abnormal sperm. Testicular biopsy showed that the seminiferous tubules contained actively-dividing germinal epithelium and apparently normal Sertoli cells. The later stages of spermatogenesis were occurring eccentrically, and the nuclei appeared abnormally shaped. It was concluded that this gorilla was incapable of fertilisation, the abnormalities being viewed as of probable congenital origin. There have been a number of similar cases in captive wild-caught gorillas (Cousins, 1990), and the sterility may not be so much congenital as a result of post-capture trauma.

Infant gorillas are often captured when local people kill the adults in reprisal for plantation destruction or for food, or both. These youngsters are kept for a later meal or used for trading, and the conditions in which they are kept and the way they are treated are far from being comparable with conditions in a modern zoo. These apes can remain for any length of time in villages, where they are often abused. In the past animal dealers would buy these animals and sell them on to zoos, by which time the apes would invariably be heavily parasitized and malnourished, and it is possible that the spermatozoa could already be seriously impaired before the animals arrived in a zoo (Cousins, 1990).

Reproductive physiology of the female gorilla

Although this paper is concerned primarily with infertility in the male gorilla, the reproductive physiology of the female cannot be ignored in some unsuccessful captive matings. Copulation outside of the female‘s peak levels of oestrone glucuronide (E1G) and pregnanediol may affect the success of pregnancy (Nadler and Collins, 1991).

Free-access and restricted-access tests were conducted with gorillas at the Yerkes Primate Research Center. In the first tests both sexes were confined together, while in the second the female was provided with means of escape. When the female had no choice, she was coerced by the male to copulate frequently, exceeding the normal monthly rate of copulation of the species, with one pair copulating on eleven consecutive days. When the females could distance themselves, however, they regulated sexual access, and the rate of copulation was reduced to that typically recorded in wild mountain gorillas (Nadler and Collins, 1991). The important factor in artificially-induced copulatory behaviour as far as the male gorilla is concerned could be the exhaustion of the precious spermatozoa before the female reaches her monthly fertility peak.

One of the interesting observations in the first series of tests was the display (chest-beating, charging and assuming the tight-lipped, stiff-legged quadrupedal stance) of the male prior to copulation. This was assumed to be threat behaviour to force the female to submit. Later, however, Nadler (1989) recorded these same displays in wild mountain gorillas prior to mating, and it would appear that in some cases these performances could be part of a ritualised courtship display. In Hannover Zoo, female gorillas in oestrus have been seen drumming with one hand on their hindquarters (Böer, 1983), and this drumming has been witnessed in other zoos (Dittrich, 1983).

In captivity female gorillas are vulnerable to the same adverse conditions as males, including stress, obesity, dietary inadequacies and illnesses. Two breeding females at Los Angeles Zoo suffered secondary infertility after being exposed to the tapeworm Echinococcus vogeli. Ultrasonic evidence revealed a progressive multi-organ echinococcosis, which was successfully treated with an 8-month trial of mebendazole (O‘Grady et al., 1981).

Concluding comments

Hill and Harrison-Matthews (1949) highlight the enigmatic nature of the male gorilla‘s external genitalia, pointing out that they are curiously primitive, or at least generalised, a position that they share with those of man. Yet this is an anomalous state of affairs for the ape, because the retarded development of the genitalia is a paedomorphic character, or even a manifestation of foetalization, a common enough feature in human anatomy, but the reverse of what occurs elsewhere in the gorilla, which is otherwise, of all the manlike apes, the most markedly gerontomorphic (infant gorillas, with their wrinkled faces and sad, dark eyes, certainly look as though they are of ancient origin). These two authors compare the great ape with the Mongoloid type of Hominidae, in that this type exhibits as high a grade of paedomorphism as any, the penis being characteristically short, and being reduced typically to a pars libera, consisting of little more than the glans, and thus recalling closely that of the adult gorilla. To add to the enigmas, the ape‘s levels of adrenal androgens are more similar to those of other non-human primates than they are to man‘s (Gould and Kling, 1982).

It is against this background of imponderables that infertility has to be identified and the cause or causes isolated. Even investigations in hormone and semen parameters give little clue as to the differences between fertile and infertile animals. Gould and Kling (1982) could find no significant differences in most hormone levels, the most important discovery being that all impotent animals had elevation of the luteinizing hormone (LH) and follicle-stimulating hormone (FSH), though the reduction in testosterone was not statistically significant. It was hypothesized that there is a feedback from the seminiferous tubules via the postulated hormone inhibin (an unknown peptide) on FSH secretion. Destruction of the seminiferous tubules would be anticipated to result in a reduction in the production of inhibin and subsequent elevation of circulating FSH levels (Gould and Kling, 1982).

Gould (1983) recommends the collection and microscopic examination of male gorilla urine samples of greater than 200 ml to identify sperm production. While not 100% reliable, demonstration of sperm in whatever numbers in the urine is evidence of complete spermatogenesis. This author believes that testes biopsy can subsequently reduce spermatogenesis. A relatively recent and simple test is the _zona-free‘ technique, which involves placing a motile sperm cell in with hamster eggs which have been treated enzymatically to remove the zona pellucida, which is the membrane surrounding the egg. If the sperm cell penetrates or _fertilises‘ a zona-free egg, then it is most likely fertile (Platz, 1987). In confirmed cases of infertility, Gould (1983) lists three types of treatment: direct (e.g. therapeutic, pharmacologic), indirect (e.g. modification and enrichment of environment and/or manipulation of diet and body weight) or evasive (e.g. artificial insemination).

There is a world of difference between total infertility and spermatogenic arrest: treatment of the latter can reverse the condition. A pair of adult gorillas at Calgary Zoo displayed breeding behaviour, but mating was never observed. A semen sample was obtained using electroejaculation. It was noted during examination that the right testicle was not descended beyond the inguinal canal, and that it was atrophied. This testicle was removed, while a biopsy specimen was taken of the left testicle, which had enlarged as a compensatory factor. Histologic examinations of the right testicle demonstrated atrophy, and of the left, maturation arrest at the spermatid stage. The gorilla was treated with an oestrogen receptive antagonist, clomiphene citrate, over a three-month period, with oral doses of 50 mg/day. Clomiphene acts on the hypothalamus to increase secretion of LH-releasing hormone, which in turn increases the pituitary production of LH and FSH. It was hoped that such endogenous gonadotrophin secretion would produce greater stimulation of the testicle, as had previously been found helpful with humans suffering from oligospermia.

After two months‘ treatment the male gorilla began to show more sexual behaviour towards the female when she came into oestrus, and mating was observed. Pregnancy was confirmed, with conception being determined as having occurred six months after surgery and four months after the beginning of clomiphene treatment (Corenblum et al., 1981).

References

Afzelius, B.A. (1981): Abnormal human spermatozoa including comparable data from apes. American Journal of Primatology 1: 175–182.

Antonius, J.I., Ferrier, S.A., and Dillingham, L.A. (1971): Pulmonary embolus and testicular atrophy in a gorilla. Folia Primatologica 15: 277–292.

Beck, B.B. (1982): Fertility in North American male lowland gorillas. American Journal of Primatology, Supplement 1: 7–11.

Böer, M. (1983): Several examinations on the reproductive status of lowland gorillas (Gorilla g. gorilla) at Hannover Zoo. Zoo Biology 2: 267–280.

Calvert, J.J. (1985): Food selection by western gorillas (G. g. gorilla) in relation to food chemistry. Oecologia 65: 236–246.

Cheraskin, E., Ringsdorf, W.M., and Sisley, E. (1983): The Vitamin C Connection. Thorsons Publishers, Wellingborough, U.K.

Corenblum, B., Taylor, P.J., and Florence, D. (1981): Successful treatment of an infertile male lowland gorilla. Journal of the American Veterinary Medical Association 179 (11): 1307–1308.

Cousins, D. (1990): The Magnificent Gorilla: the Life History of a Great Ape. Book Guild, Lewes, U.K.

Dittrich, L. (chairman) (1983): International Symposium on Great Apes: Infertility and insufficient breeding in great apes due to inadequate keeping systems: prophylaxis by environment alteration and therapy. Zoo Biology 2: 315–333.

Dixson, A.F., Moore, H.D.M., and Holt, W.V. (1980): Testicular atrophy in captive gorillas (Gorilla g. gorilla). Journal of Zoology (London) 191: 315–322.

Fisher, L.E. (1954): Lead poisoning in a gorilla. Journal of the American Veterinary Medical Association 125: 478–479.

Foster, J.W., and Rowley, M.J. (1982): Testicular biopsy in the study of gorilla infertility. American Journal of Primatology, Supplement 1: 121–125.

Gould, K.G. (1983): Diagnosis and treatment of infertility in male great apes. Zoo Biology 2: 281–293.

Gould, K.G., and Kling, O.R. (1982): Fertility in the male gorilla (Gorilla gorilla): relationship to semen parameters and serum hormones. American Journal of Primatology 2: 311–316.

Graffikin, P. (1949): Gorilla gorilla beringei: post-mortem report. East African Medical Journal 27: 224–227.

Hall-Craggs, E.C.B. (1962): The testes of Gorilla gorilla beringei. Proceedings of the Zoological Society of London 139: 511–514.

Hill, O.W.C., and Harrison-Matthews, L. (1949): The male external genitalia of the gorilla, with remarks on the os penis of other Hominoidea. Proceedings of the Zoological Society of London 119: 363–378.

Hosokawa, W., and Kamiya, T. (1962): Anatomical sketches of visceral organs of the mountain gorilla (Gorilla gorilla beringei). Primates 3 (1): 1–28.

Jones, D.M., Dixson, A.F., and Wadsworth, P.F. (1980): Interstitial cell tumour of the testis in a western lowland gorilla. Journal of Medical Primatology 9: 319–322.

Jouventin, P. (1975): Observations sur la socio-écologie du mandrill. La Terre et La Vie 29: 493–532.

Karesh, W.B., Burton, M.S., Russell, R.G., and Burns, M.W. (1988): Leydig cell tumour in a western lowland gorilla (Gorilla gorilla gorilla). Journal of Zoo Animal Medicine 19 (1–2): 51–54.

Keeling, M.E. (1982): Veterinary perspectives of infertility in male great apes. American Journal of Primatology, Supplement 1: 87–95.

Koch, W. (1937): Bericht über das Ergebnis des Obduktion des Gorilla _Bobby‘ des Zoologischen Gartens zu Berlin: ein Beitrag zu verleichenden Konstitutionspathologie. Veröffentlichungen Kunst-Wehrpathologie 9: 1–36.

McKenney, F.D., Traum, J., and Bonestell, A.E. (1944): Acute coccidiomycosis in a mountain gorilla (Gorilla beringei) with anatomical notes. Journal of the American Veterinary Medical Association 104: 136–140.

Nadler, R.D. (1989): Sexual initiation in wild mountain gorillas. International Journal of Primatology 10 (2): 81–92.

Nadler, R.D., and Collins, D.C. (1991): Copulatory frequency, urinary pregnanediol and fertility in great apes. American Journal of Primatology 24: 167–179.

O‘Grady, J.P., Esra, G.N., Yeager, C.H., and Thomas, W.D. (1981): Evaluation of secondary infertility in the gorilla. American Association of Zoo Veterinarians Annual Proceedings 14: 131–132.

Platz, C.C. (1987): Evaluating the fertility of the male lowland gorilla. Kudu Review (New Mexico Zoological Society) 18 (4): 13–17.

Platz, C.C., Wildt, B.S., Wildt, D.E., Bridges, C.H., and Seager, S.W. (1979): Fertility analysis in the lowland gorilla and siamang gibbon using electroejaculation. American Association of Zoo Veterinarians Annual Proceedings 12: 88–90.

Platz, C.C., Wildt, D.E., Bridges, C.H., Seager, S.W., and Whitlock, B.S. (1980): Electroejaculation and semen analysis in a male lowland gorilla Gorilla gorilla gorilla. Primates 21 (1): 130–132.

Sattersfield, W.C., and O‘Rourke, K.I. (1982): Veterinary issues: discussion group report. American Journal of Primatology, Supplement 1: 127–129.

Schultz, A.H. (1939): The relative weight of the testes in primates. Anatomical Record 72 (3): 387–394.

Seuanez, H.N., Carothers, A.D., Martin, D., and Short, R.V. (1977): Morphological abnormalities in spermatozoa of man and great apes. Nature 270: 345–347.

Short, R.V. (1979): Sexual selection and its component parts, somatic and genital selection, as illustrated by man and the great apes. Advances in the Study of Behavior, Vol. 9, pp. 131–158. Academic Press.

Steiner, P.E. (1954): Anatomical observations in a Gorilla gorilla. American Journal of Physical Anthropology 12 (2): 145–178.

Steiner, P.E., Rasmussen, T.B., and Fisher, L.E. (1955): Neuropathy, cardiopathy, hemosiderosis, and testicular atrophy in Gorilla gorilla. Archives of Pathology 59: 5–25.

Wislocki, G.B. (1942): Size, weight and histology of the testes in the gorilla. Journal of Mammalogy 23: 281–287.

Don Cousins, Flat 3, 45 Silverdale Road, Lower Meads, Eastbourne, East Sussex BN20 7AT, U.K.

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LETTER TO THE EDITOR

Dear Sir,

Ken Kawata implies (I.Z.N. 47/6, pp. 373–4) that he might approve of a resurgence of the travelling menageries _on a limited basis, with fewer species‘. As I‘ve always believed this gentleman to have his finger on the pulse of wild animal husbandry matters, I‘m somewhat surprised to deduce that he has seemingly yet to hear of a travelling menagerie which has been trundling through town and village – à la Bostock and Wombwell, but in Switzerland – for nearly a decade now.

Owned and operated by a well-known and respected animal-trainer named René Strickler, it‘s known as _Freundschaft mit Raubtieren‘ (Friendship with Carnivores), and currently consists of 33 animals – lions, tigers, leopards (both spotted and melanistic), American and Asiatic black and polar bears, and pumas. Unexpectedly many are sponsored by individuals and companies – Esso and Coca Cola being prominent among the latter, and Princess Stephanie of Monaco among the former.

On setting up, large enclosures furnished with such appropriate facilities as platforms, logs, rockwork and even pools are erected adjacent to the modern beast wagons, and during the two-hour _show‘ Strickler uses a radio microphone to introduce the animals as they are released into their pens and to comment on their characteristics, such as climbing and jumping. He also – zoological gardens please note, as this is much appreciated by the paying public – comments on their individual characters and temperament.

Obviously, the running and erecting of such an outfit entails a great deal of strenuous work, but it‘s clearly much appreciated in a country with a noted humane ethos, as during a ten-day stand in Lucerne earlier this year it was visited by no fewer than 117,000 people. If, then, it heralds the possible re-birth of a decidedly different type of travelling menagerie I, for one, shall be delighted.

Yours faithfully,

Clinton Keeling,

13 Pound Place,

Shalford,

Guildford,

Surrey GU4 8HH,

U.K.

* * *

CONSERVATION

Saving the Antiguan racer – a progress report

For several years, the Environmental Awareness Group (EAG) has been the sole non-governmental agency fighting to protect the fragile terrestrial and marine environment of Antigua and Barbuda, and the dozens of offshore islands and reefs dotting the coastline of the two larger islands of this Caribbean nation. On one of these small islands, a small and harmless snake, the Antiguan racer (Alsophis antiguae), was rediscovered in 1989. Long extinct on the larger islands due to depredation by introduced rats and dwarf mongoose, the only wild population of this snake is known from Great Bird Island, a 20-acre [8 ha] speck of land off the north-east coast of Antigua. In 1995 a British conservation group, Fauna and Flora International, joined forces with the EAG and the Antiguan and Barbudan government in attempting to thwart the impending extinction of this snake.

A project to eradicate the rats on the island was conducted in early 1996. Within a year, the racer population had rebounded from 50 to approximately 100 individuals. Realizing that a population of 100 is nowhere near a stable size, the two conservation agencies and the government joined forces, forming the Antiguan Racer Conservation Project (ARCP). Eventually becoming a consortium of five members, the ARCP realized that long-term survival of the species would only be possible by reintroducing the snakes to other offshore islands. While it is not possible to eradicate rats and mongoose from the larger populated islands of Antigua and Barbuda, these two introduced predators can be controlled on the small, unpopulated offshore islands, allowing an opportunity for racers to survive on these islands, with appropriate management. From 1996 to 1999, the ARCP has cleared several offshore islands of rats. An extensive public education plan has also been launched, largely spearheaded by the EAG. The plight of the snake has been featured in most Antiguan media outlets, and television specials on the snake have been aired throughout the Caribbean region.

By 1999, enough islands had been cleared of introduced predators for the ARCP was able to begin a reintroduction campaign. However, as of 1999, no research had yet been conducted on the prey of the snake, which is known to consist exclusively of lizards. In 1999, Black Hills State University, South Dakota, U.S.A., with funding from Columbus Zoo, initiated a long-term study of the lizards of these offshore islands. Our goal is to obtain baseline data on these lizards and to guide the reintroduction effort through knowledge of the snake‘s prey base on a variety of offshore islands. We will continue to follow population fluctuations of the lizards as snakes are introduced, and we have a most unusual opportunity to observe first-hand how prey and predator populations fluctuate as a top predator is reintroduced to portions of its natural range.

Also important to the ARCP is the transfer of skills to local counterparts within Antigua and Barbuda. In our initial field season, we were, in part, attempting to determine the techniques that worked best to survey lizards as well as collecting baseline data. However, we were also able to work with our local colleagues in the ARCP and pass on some of our techniques. Now that we have a well-researched study design, skills transfer will assume a more important role. In the future, we hope to begin working with Antiguan and other Caribbean students as part of a long-term plan to turn this project over to Caribbean scientists. We believe that, over a period of five to ten years, we will have completed our initial monitoring of the reintroduction project, and hopefully we will also have completed our training mission. We believe that the future of conservation in the Caribbean will lie in the hands of Caribbeans, and with our local counterparts in the ARCP and local student help, we hope to see that future.

Dr Brian Smith, Black Hills University, in The Conservationist (Columbus Zoo) Vol. 5, No. 1 (July 2000)

[The first captive breeding of the Antiguan racer took place at Jersey Zoo in 1996 (see I.Z.N. 44:3, p. 159) – Ed.]

 

The Asian turtle crisis

I informed the participants in the EAZA/EEP Conference in Alphen a/d Rijn in 1997 about the serious situation regarding Asian turtles, and in particular the Chinese species. A number of turtle species in China, described as new species or discovered in the 1990s, can already be considered extinct in the wild. Species such as Cuora zhoui, C. mccordi, C. aurocapitata and C. pani only exist in captivity. Not only Asian turtles are at risk: the well-organised Chinese commercial network makes it possible to collect turtles in virtually any location in the world, and indeed the preference of Chinese consumers for wild-caught animals is the cause of the decline of wild turtle populations globally. Conservationists have repeatedly warned that if no internationally directed, adequate action is taken, many more turtle species are likely to disappear worldwide within a few decades.

There was general agreement at the 1997 conference on the need for an international approach to the problem and the initiation of breeding programmes or studbooks for Asian turtle species, and many participants also felt that cooperation between zoos and private breeders in European herpetological societies could be considered as an option. To my regret, however, I have noticed hardly any activity in the European zoo community since 1997. Perhaps individual zoos breed endangered Asian species, although such breedings are not reported in the International Zoo Yearbook or elsewhere. Volume 36 of the Yearbook, reporting captive breedings in 1995/1996, mentioned production of 263 animals of 13 Asian species in 24 zoos worldwide – a disappointingly low figure given the number of species that are currently under threat. While it is generally acknowledged that indeed many species are threatened, the Yearbook only reported on three endangered Asian species (Batagur baska, Calagur borneoensis and Orlitia borneoensis) in its regular survey _Rare Animals in Captivity‘.

To my knowledge, only Rotterdam Zoo is currently seriously attempting to breed Geoclemmys hamiltoni, Cuora amboinensis, C. trifasciata, Lissemys punctata, Ocadia sinensis and C. galbinifrons. The first three species have already bred successfully there. Münster Zoo is planning to build a greenhouse containing breeding facilities for endangered Asian species. Fund-raising by the Zoologische Gesellschaft für Arten- und Populationsschutz should make this possible, and building of the breeding centre is scheduled for next year. The captive population of a number of endangered species owned by private breeder Elmar Meier will be housed there. In my opinion EAZA zoos can and should do more. For too many species, captive reproduction is the only means to prevent extinction in the short term, and cooperation between professional organisations and private turtle keepers may be essential in preventing this scenario.

Abridged from Henk Zwartepoorte (Rotterdam Zoo) in EAZA News No. 31 (July–September 2000)

 

Announcing the launch of The Good Zoo Guide Online

A valuable new internet service has been launched, designed to meet the needs of zoo visitors, conservationists and lovers of wildlife. Based on John Ironmonger‘s top-selling British paperback The Good Zoo Guide (Harper Collins, 1992), the new internet service aims to become the essential guide to the zoos and wildlife collections of the world. It offers visitors the opportunity to post their own _zoo critiques‘, and will carry official zoo descriptions as well as links to zoo sites. We will depend upon cooperation from good zoos for our success. For example, we would like to be able to offer a search feature so that _zoo twitchers‘, like ourselves, can find out where to go to see our favourite animals, but to do this we will need species lists – which we will publish – from every zoo.

U.K. zoos cooperated generously with the paperback version of The Good Zoo Guide. The result was a valuable book with full species guides to every collection. Please help us by cooperating and contributing to The Good Zoo Guide Online. We hope that the result will help to support the work of all zoos, worldwide. We believe in the good work that zoos are doing, and this is our way of supporting it.

Please visit the site at www.goodzoos.com and let us know your reactions. It is only in its very early stages, and we realise it is still very _British‘ at the moment, but there is plenty of time for it to grow. Reply by e-mail to editor@goodzoos.com with questions or comments about this web site.

* * *

MISCELLANY

Where are all the genetic errors?

One reason for starting San Diego‘s Frozen Zoo back in 1975 was so that we could compare chromosome structure and numbers from many animal species. My interest was to fathom their relationship, evolutionary lineage, the possibility of fertile hybrids, should such occur, and to gain an understanding of genetic errors. I see many of those in human cases in the hospital with which I am associated, and it has long been a mystery to me why so many fewer spontaneous abortions occur in animals and why we see so few chromosomal errors. We have come a long way in understanding the relationship of the horse family, of many African gazelles, and the evolution from the chamois to the Rocky Mountain goat, for instance, but rarely do we encounter errors like those that cause human spontaneous abortions or mental retardation. It is a major challenge, and we have not made much progress in our understanding of these differences.

Imagine my surprise when a chromosomal alteration was identified in one of our gorillas. A five-year-old male was found to be growth-restricted, growing very little. Otherwise, he looked good, had normal integration with the troop, and nothing much was found during a detailed veterinary examination and radiology, except that his testicles had not descended. He had the normal number of chromosomes (48 for gorillas, 46 for humans), but one large chromosome had a big chunk missing. This abnormality has now led to a detailed study of this ape, and eventually a scientific paper will come from it. Because we know the nature of the corresponding human chromosome (having an essentially identical banding pattern), we can guess which proteins the missing genes are coded for, so this has become a fascinating problem for the Center for Reproduction of Endangered Species and the gorilla animal care staff.

I am very pleased with this finding, because the near absence of such errors reported to date has made me nervous – _What are we missing?‘ is my constant question. Well, what we are missing is probably a better understanding of the normality or subtle abnormalities in animals. Either we do not observe them well enough or the symptoms of possible genetic errors such as this one are too minuscule for us to detect. We shall be more circumspect in the future!

Abridged from Kurt Benirschke, M.D., President, Zoological Society of San Diego, in Zoonooz Vol. 73, No. 9 (September 2000)

 

Savigny‘s eagle owl – information and help requested

There has been a marked decline in the captive-breeding of Savigny‘s eagle owl (Bubo ascalaphus) in recent years. An independent research project is underway to determine the cause of this decline, operating from the hypothesis that lack of genetic fitness is the primary factor.

To examine the genetics of the historical and current population, it is necessary to analyse as much information as possible. To this end, provision of all current and historical information would be very much appreciated from anyone who keeps, or has kept, this species.

Relevant requested information includes: historical stock information; breeding birds (origin, parent information); breeding records (clutch sizes, infertile eggs, chicks hatched, chicks not surviving, chicks fledged); destination of fledged chicks; anecdotal information (history of the species, sources, breeding).

A primary aim of the project is to contribute towards the successful keeping of all owl species now and in the future, through a greater understanding of population dynamics. All information will be kept strictly confidential. With permission, full acknowledgement and thanks will be made in the final report to all groups and individuals assisting with the project.

If you are able to assist with information for this project, please contact: Campbell Murn, Conservation Coordinator, The Hawk Conservancy, Andover, Hampshire, SP11 8DY, U.K. (Tel.: ++ (0)1264 773850; Fax: ++ (0)1264 773772; E-mail: cmurn@hawk-conservancy.org)

 

An unusual alternative to hand-rearing?

In a thought-provoking Guest Editorial in Tyto, the journal of the International Owl Society, Bernard Sayers discusses the controversial topic of the commercial farming of non-domestic animals. This follows a recent suggestion that common, easily-managed species of owls could be bred in captivity to satisfy some of the demand for owl body parts from practitioners of traditional medicine and witchcraft, thus reducing pressure on much rarer species in the wild.

What really caught my attention, however, was Mr Sayers‘ report on his wife‘s recent visit to a crocodile farm in Thailand which has recently begun to breed tigers in large numbers for commercial purposes. Like him, I find this idea extremely unattractive at first sight; but I don‘t want to discuss its ethics at present. The aspect of the farm‘s practice which may be of interest to zoo people is that the tiger cubs are routinely removed from their mothers to be suckled by domestic sows. As Mr Sayers comments, this technique is one that zoos might be able to adapt for rearing abandoned cubs of other felines – or indeed, I would add, young mammals of other species.

Nicholas Gould

 

First genetic evidence for a third species of elephant

African forest elephants are normally classed as a separate subspecies, Loxodonta africana cyclotis, on the basis of their clear physical differences from the more familiar bush or savanna elephant – straighter tusks, rounder ears, etc. Now, however, researchers at the Natural History Museum in Paris claim that forest elephants are genetically different enough from their bush cousins to be classed as a separate species. The claim is based on tests made by molecular biologists at the museum on DNA taken from Coco, an elephant at Vincennes Zoo who is thought to be the last surviving forest elephant in a European zoo. Preliminary results showed that Coco‘s mitochondria differ from those of bush elephants as much as they do from those of Indian elephants. Moreover, the scientists‘ latest research indicates that there are equally great differences between the animals‘ nuclear DNA. These results suggest that there are probably two species of elephant in Africa; but more individuals need to be tested to confirm whether this is the case.

Adapted from New Scientist, 1 April 2000, p. 15

* * *

ANNUAL REPORTS

COPENHAGEN ZOO, DENMARK

Annual Report 1999 – extracts from the English language summary

The animal collection

One of the highlights of 1999 was the birth of a healthy male reticulated giraffe calf. On 16 February our oldest female, Frk. Knudsen, produced the 54th calf in the zoo‘s history, and also the sixth male in a row since 1991, when the other female, Julie, was born. Within the EEP there is a shortage of females, making it increasingly difficult to dispose of males. Then in May Julie delivered a long-awaited female calf. It is now up to the species coordinator to find other places for the two young giraffes. We aim to exchange the young female with an unrelated female from another zoo in order to get a core group of one male and three unrelated females.

Other notable births included three Siberian tiger cubs, of which one was still-born. The other two were healthy and quickly started begging for milk, but the female did not have enough and was very restless. After a couple of days the cubs became dehydrated and had to have supplemental milk. The keepers continued to give milk replacement in small amounts while encouraging the cubs to suckle their mother, in order to make her take care of them and keep up her production of milk. We succeeded in making her accept the cubs, and during the autumn the group joined the male.

In June the rheas had five chicks. As usual the male was in charge of incubation, and immediately after the chicks hatched you could see five miniature rheas strutting about on the pampas. The male did not allow any of the other animals to come close to the chicks, and became so aggressive that he and they had to be moved temporarily from the pampas.

The two-toed sloths had their sixth young born in the zoo. The oldest youngster – a female born in 1997 – was removed from the Rain Forest Hall to prevent it from competing with its parents, and was sent to Duisburg Zoo, Germany, later in the year.

Our lonely giant anteater died early in the year at almost 20 years old. She arrived at the zoo in 1983 and produced a total of six young – two of them being twins who unfortunately died soon after birth. Giant anteaters do not breed well in captivity – every year only one or two are born in European zoos. In order to improve breeding results, it is of great importance to conduct systematic studies of their behaviour and physiology. Copenhagen Zoo wishes to contribute to procuring this kind of information, and will follow future anteaters in the zoo very closely.

Veterinary report

In January the second and last of the red panda cubs died. The post-mortem revealed that it had died of starvation. The female had not led it to the feeding site as she usually would. This neglect was probably due to the cubs being born late in the year. When the female came on heat again, it coincided with the period when she would usually have devoted herself entirely to the cubs.

Rats had brought rat poison into the ravens‘ aviary, and as birds are sensitive to rat poison, both ravens were given antidote treatment; they did not subsequently show any sign of poisoning.

In March the female pygmy marmoset, who was almost through her pregnancy, became ill, and an examination showed dystocia due to large foetus size. The marmoset, which weighed 145 g before the caesarean, was anaesthetised and three big male young (15 g, 15 g and 16.5 g) were removed. The one that had been stuck in the birth canal was dead and another was very weak and died shortly after the surgery. The last baby was strong and lively, and when the vet had sutured the female, it was placed on her back and they joined the male. We were curious to see if the male would take over the care of the baby – as he is supposed to – although he had not been present at its birth. He quickly took on his responsibility, and several times during the night he brought the young to the female to nurse. Sadly, however, the baby marmoset caught pneumonia and died a couple of days later.

The Asian elephant cow Inda became unsteady on her feet and staggered about. Two days later the bull, Chieng Mai, developed the same symptoms. It turned out to be mycotoxicosis caused by a type of fungus in their rye-grass (Lolium perenne) fodder. At a quality check a hole had been made in the plastic covering the bale, and although the hole had been carefully sealed it had been enough to start fermentation. The disease is well-known in horses and sheep, and is called _rye-grass staggers‘. The elephants recovered after a couple of weeks.

An infected tooth appeared to make a female Nile crocodile ill. She was treated with different types of antibiotic and moved to a warm cage. The first week she got better, but then she relapsed despite intensive treatment, and finally became so ill that she had to be euthanised. The post-mortem revealed no gross abnormalities, but a subsequent microscopy of all organ systems showed heavy iron deposit in the liver and hyaline degeneration of the kidneys.

A newly-weaned Grant‘s zebra filly who arrived from Kolmården Animal Park in Sweden had been sedated with a long-acting tranquilliser from which she developed severe side-effects (extrapyramidal symptoms). The zebra had compulsive movements and abnormal head posture, but all symptoms disappeared after an anti-Parkinson medication was administered. In just two days she recovered and is now thriving.

The female Malayan tapir had a vigorous eczema on the back of the head and down the neck. She had mated several times and might be carrying a calf, so anaesthesia and a skin biopsy were less than desirable. Contact was made with researchers at the Danish Institute of Agricultural Sciences, who take skin biopsies of pigs by means of a special biopsy gun without anaesthesia. Two scientists arrived, the tapir was enticed with bananas and three biopsies were taken. The animal hardly reacted to the biopsy, but the very thick and leathery skin at the back of the neck only made it possible to take a small sample. It was sent to England, and following the result (a superficial pyodermia) the tapir was put on antibiotics and zinc ointment and recovered within three weeks.

Research

A number of behavioural studies were carried out in cooperation with the Zoological Institute at the University of Copenhagen. These included:

Social organisation of black-tailed prairie dogs (Cynomys ludovicianus). The study involved recording the activity pattern, the social behaviour and the whereabouts of each individual in the enclosure. Based on these records the animals‘ activity, social organisation and social interactions were described. The prairie dogs spend most of the time above ground to feed and to look out for enemies. The actual behaviour depended on the age, sex and social status of the animals. The colony was clearly divided into territories each dominated by a female. The dominant male had access to both territories, and was the only one allowed to move freely. The animals‘ choice of holes differed greatly and seemed to emphasise the rank of each individual.

Stereotypic behaviours in polar bears. The report contains a theoretical study of the biology, stress symptoms and stereotypes of polar bears in general, as well as problems relating to keeping them in captivity, all based on literature studies. Additionally, the occurrence of stereotypes in the polar bears at Copenhagen Zoo have been recorded during a longer period and related to the time of day, the time of year, the time of feeding and the number of visitors around the enclosure. Based on the occurrence of the stereotypes, suggestions were made on how to enrich the present enclosure in order to reduce stereotypic behaviour. The stereotypes proved to be dependent on the individual bear – different bears showed different kinds of stereotypes. Some stereotypes were more prevailing in the morning while others occurred throughout the day. Finally, the frequency of the stereotypes changed throughout the year. There seemed to be a connection between the occurrence of stereotypes and the number of visitors around the enclosure, but without any clear answer as to cause and effect.

 

MARWELL ZOOLOGICAL PARK, U.K.

Extracts from the Annual Report 1999

The animal collection by Peter Bircher

The birth of a female okapi in late December 1998 gave us the task of hand-rearing this calf in early 1999 when she was rejected by her mother, Bibi, who had also rejected her first calf, Elila, in 1997. Elila was the first okapi to be totally hand-reared from birth in any zoo worldwide, and we were more confident of success with our second calf. Elila had been attacked at birth by Bibi, but our second calf fared much better. Bibi showed positive maternal interest in her offspring, licking and stimulating the calf to stand. However, her behaviour changed when the calf tried to suckle, and forcefully kicked it if it persisted. After one such kick temporarily stunned the calf, she was removed for hand-rearing. The calf, Zukisa, was immediately given antibiotics and vitamins and started on fresh whole milk from a local herd of Guernsey cows. During the six months of hand-rearing she suffered no serious setbacks, and her physical development and weight gain followed the same steady progress shown by Elila.

The birth of a white rhinoceros calf in early February was the highlight of 1999. Bhasela was the first calf born at Marwell and also the first full second-generation animal bred in the U.K. Numerous white rhinos have been bred in captivity worldwide, but in almost all cases one of the two parents has been wild-caught, so the Marwell birth was a significant event for the captive breeding of this species. Even more pleasing for us was the fact that first-time mother Sula, aged twelve years and six months at the time of birth, proved to be an exemplary parent, nursing her offspring most tenderly.

On a smaller scale, Marwell joined forces with English Nature and Sparsholt College, when a total of 29 water voles (Arvicola terrestris) arrived prior to their release in a selected site in southern England. This species is seriously in decline in parts of Britain. We are delighted to be further involved in the conservation of native fauna, together with our established captive-breeding programmes for sand lizard, natterjack toad and reddish buff moth. We have also joined a similar programme for the highly endangered European hamster (Cricetus cricetus). A specialised unit dedicated to breeding rodents, with public viewing facilities, will be in operation early in 2000. Exhibiting our growing collection of small mammals was enhanced by the opening of _Nightlife‘ next to Marwell Hall; species on display include Senegal bushbaby, kowari, and an assortment of small rodents.

The second breeding success of the year was the birth of a litter of eight (5.3) cheetah cubs, all of which survived. To the best of our knowledge there have only been two or three litters of this size ever recorded in captivity. The cubs are also important in genetic terms. The father was imported from South Africa eight years ago and, despite being paired with females in other zoos, had shown no interest in breeding. Our concerns about the natural ability of the female to rear so many cubs successfully were confirmed when one cub was examined with a swollen leg joint. X-ray investigation revealed early evidence of nutritional bone disease, and two further cases showed this to be likely in most of the litter. Fortunately, the cubs were fully weaned, so the treatment of their food with higher levels of selected vitamins and minerals presented no major problems. The condition was successfully treated over a period of several weeks and their health is no longer a cause for concern.

The sudden death of a young adult African penguin in May after a short illness was the prelude to a devastating problem, which resulted by mid-October in the loss of our entire colony of 28 birds, 22 African and six macaroni [see I.Z.N. 47:3, pp. 194–195 – Ed.]. After many hours of searching blood and tissue samples, evidence of the avian malaria parasite was eventually found in some of the birds, though the lack of other findings still caused some experts to remain unconvinced, and we agreed to continue our investigations until every possibility had been explored.

A protocol for the re-stocking of Penguin World involving preventive treatments, disease monitoring and other mosquito control measures was drawn up, and a study to determine the incidence of malaria in indigenous bird species was also proposed. We would also, with the assistance of Dr Mike Cranfield, Senior Veterinary Officer, Baltimore Zoo, U.S.A., a leading authority on the disease, carry out DNA typing of the parasite in order to determine if it is a new and more pathogenic variant.

The arrival of a sub-adult pair of wart hogs from Antwerp (0.1) and Rotterdam (1.0) fulfilled my dream of exhibiting this species at Marwell. Wart hogs are not strictly endangered, but there are very few of them currently in European zoos. Our animals are the progeny of several animals imported direct from Africa into special quarantine facilities at Antwerp Zoo. They are supplied to Marwell on condition that we contribute to the cost of importing the original animals which, because of the special quarantine requirements in both Africa and Belgium, proved a very expensive exercise.

Boris, our male Siberian tiger, had to be euthanased because of kidney disease; during his 18 years at Marwell he sired a total of 14 cubs which are now distributed throughout the world. On reporting his death to the species coordinator, we were requested by the IUCN/SSC Cat Specialist Group to save his penis. Field conservation officers have great difficulty in trying to identify dried penis offered for sale in the Far East. The idea was to subject a known penis to the same preservation techniques employed in oriental medicine and use it for comparison.

A young female Somali wild ass imported from Israel was a welcome addition to our group, now totalling 3.3 animals. This is the second animal from the National Biblical Wildlife Reserve, Hai-Bar, Eilat, where Marwell has funded quarantine facilities that meet import requirements for equids into the E.C. Marwell is still the only zoo with this species in the United Kingdom.

Veterinary report by Giles Summerhays

This year we finally lost the battle in the treatment of extremely aggressive sarcoids (skin tumours) on one of our Hartmann‘s zebras. Sarcoids have been a group problem for some years in the Hartmann‘s, but interestingly have never been seen in the Grevy‘s zebras kept 50 yards away. The tumours have predilection sites in front of the mammary gland in females or around the sheath or penis in males. In the last ten years we have had six zebras affected and have tried numerous treatments, including en bloc resection plus cryosurgery, intralesional BCG and, most recently, a cream developed by Dr Knottenbelt at Liverpool University. This cream has to be applied onto the surface of the sarcoids daily for four or five treatments. Because of the large size of the zebra sarcoids and the impossibility of daily treatments without general anaesthesia, the cream has been injected directly intralesionally. This results in marked necrosis and sloughing of the tumour and, in one zebra, complete resolution of a tumour about 10 cm in diameter. In the case of Sophie, the tumours were extensive and ultimately we were fighting a losing battle with re-growth occurring at a faster rate than tumour necrosis. The treatment, however, has given the most favourable results to date and has allowed this particular mare to breed and rear a healthy foal. The treatment is frustratingly subjective, as Liverpool University keeps the constituents of the cream a well-guarded secret.

Field research by Simon Wakefield and Renata Molcanova (Zoo Bratislava)

The transport of captive-bred scimitar-horned oryx to three national parks in Tunisia was finally realised in 1999, after a year of intense preparation and planning. The main focus of the project was the 60 km2 Parc National de Sidi Toui, in the south of Tunisia, where a group of ten (1.9) animals were released on 29 April, 49 days after their arrival in Tunisia. The project is being jointly coordinated by Marwell and Zoo Bratislava in the Slovak Republic.

The choice of the animals for Sidi Toui was governed by several factors – that they should be a genetically separate line to the existing population in Bou Hedma National Park, to be as genetically diverse within the release group as possible, and to have an age and sex structure which will allow early development of a stable group structure, which is essential to a successful release. The donation of three adult females from Zoo Bratislava, who were also pregnant by an unrelated male on arrival in Tunisia, was a key factor in achieving all three objectives. A total of 14 oryx came from six zoos – Bratislava, Paris and La Palmyre (France), Leipzig (Germany), Dvur Kralove (Czech Republic) and Valbrembo (Italy). Of these, four were transported after quarantine to two other parks: 1.2 were sent to Oued Dekouk to establish the first oryx there, and an adult male was donated to Bou Hedma to become the first addition to the park since the original transport of animals there from Marwell and Edinburgh in 1985. In addition, two female slender-horned gazelle (G. leptoceros) – a threatened species in North Africa – had been donated to the park by Planckendael Zoo in Belgium, to pair with a hand-reared male kept in Sidi Toui; management advice is being given to establish a small captive-breeding facility for this species.

During their initial acclimatisation phase in small purpose-built pens, the female oryx for the Sidi Toui group were slowly integrated with each other, allowed to settle and establish a hierarchy, before being introduced to the breeding male in the 10-ha pre-release enclosure. Observations were made of social behaviour and daily activity patterns and, once they were in the pre-release enclosure, it was also possible to assess their preferences or the natural vegetation.

Once the herd was considered to be a social unit, they were released to the National Park. Two of them were fitted with radio collars, and radio-tracking and monitoring was conducted all through the summer until September, in accordance with the IUCN/SSC Reintroduction Specialist Group‘s guidelines. Further funds are being sought to continue and expand the project, and a proposal has been put forward for a three to four year programme, encompassing five national parks and focused on four species (scimitar-horned oryx, addax, slender-horned gazelle and Cuvier‘s gazelle).

* * *

INTERNATIONAL ZOO NEWS

Center for Reproduction of Endangered Species, San Diego, California, U.S.A.

One of the Zoological Society of San Diego‘s major initiatives is to conserve genetic resources from a growing diversity of species. Accordingly, a conference, _Genetic Resources for the New Century‘, was held on 7–11 May 2000 in La Jolla, California. An international group of speakers attended, scientists prominent for their innovative and far-reaching research contributions. Access to genetic resources was highlighted as a global concern. A striking new opportunity for linking ex situ and in situ conservation was advanced. It was also agreed that Web-based DNA libraries contribute significantly to efforts to assess, monitor, manage, and recover endangered species.

The Zoological Society is actively exploring the design of a Web site to collect information about DNA banks. While there are many more species that are threatened with extinction or that are becoming extinct without being named, our initial efforts focus upon learning how many endangered species are represented in DNA collections and whether they are accessible. We have already exchanged some information with collections in Cape Town, Paris, Göttingen and Kunming (China).

The conference proceedings will be published as a book in 2001, which should broaden the dialogue about the impact of genomic sciences on our understanding of biology and the urgent need to preserve genetic material for future study. This meeting also created an informal network among the participants, leading to a more coordinated effort for collecting and sharing information. It is our sincere hope that this new knowledge will open up a wider discussion on genomic biodiversity conservation via academic seminars, follow-up conferences, and discussions within the conservation community. This can establish links between conservation organizations and biodiversity management programs, as well as the genomics/biotechnology/pharmaceutical industries. The Society is proud to have initiated this effort and continues to educate our members and guests at our Frozen Zoo site: www.sandiegozoo.org/cres/

frozen.html. This site also holds our Genetic Resource List, a comprehensive list of samples available to the scientific community. It is one way that CRES can encourage dialogue and an exchange of information in a field that is critically important for the future of endangered species.

Abridged from Oliver Ryder in CRES Report (Fall 2000)

 

Cologne Zoo, Germany

The zoo has been keeping a bachelor group of Grevy‘s zebra since 1995. Five of the six stallions who formed the first group have now become harem stallions in other zoos. One stallion had to be put down because of an inflammatory condition resistant to treatment. After a regrouping in 1997/98, the herd now consists of three young and one nine-year-old stallion. The latter had to bc castrated in January 1999.

So far, neither the grouping of several stallions nor the introduction of new stallions to the established group has ever caused such problems as overt aggression or even injury. Observations of social behaviour were carried out during three different time periods. These studies demonstrated that the stallions easily formed close bonds, mostly with individuals in the neighbouring stalls. Therefore it seems advisable to keep groups with even numbers only and to put newcomers into neighbouring stalls or next to a stallion who has not been able to establish a bond with another resident male.

High-level agonistic interactions were rarely observed; the only exception to this was the nine-year-old, Saldo. The three studies showed that the bachelor zebras do not live in an egalitarian system, but that differences in dominance status exist. This dominance hierarchy becomes apparent not only in the animals‘ agonistic behaviour, but also in their play-fighting and marking behaviour. The differences in dominance status are most pronounced between the three-year-old stallions and the younger ones, and seem to point to the existence of several ontogenetic stages of behaviour. There has only been one stallion older than five years in the bachelor groups so far. Therefore it is difficult to tell whether his behaviour, especially his increased rate of aggressive interactions, must be attributed to a normal maturation process or is the consequence of the illness of the subordinate stallion, who was the prime target of his attacks. In the current state of knowledge it is impossible to predict whether older stallions tend to _mate‘ with younger ones. This may well have been an exception. Similar instances have been reported from other captive equids.

In any case, the establishment of bachelor groups should not be a static measure, but should simulate the dynamic conditions of the wild Grevy‘s zebra population, in which young stallions join the bachelor groups and/or older ones leave it in order to become territorial. The experience gained in our years of keeping a bachelor group in Cologne could be the basis of future recommendations issued by the EEP management.

It should also be mentioned that a zoo keeping a stallion group is faced with higher costs due to more frequent transportation. But considering that nowadays no costs arise from the exchange of animals, these costs resulting from improved keeping conditions should be regarded as money well spent. In addition, the great activity of the zebras must be seen as a reward for the zoo‘s efforts. In particular, their frequent play-fighting, wallowing and marking rituals allow visitors an insight into many aspects of their natural behaviour patterns.

English summary of an article by Brigitte Heuschkel, Annette Kröhne and Waltraut Zimmermann in Zeitschrift des Kölner Zoo Vol. 42, No. 3 (1999)

 

Columbus Zoo, Ohio, U.S.A.

The zoo‘s new manatee exhibit provides its inmates with a state-of-the-art facility and offers visitors an opportunity to view these gentle creatures up close. The exhibit was completed in May 1999, when four manatees were flown in from Orlando, Florida. The animals adjusted quickly to their new surroundings and settled into their role as ambassadors, entertaining and educating visitors and enthusiasts about manatees and the problems that they face. These four are _rehab animals‘, manatees maintained in captivity for rehabilitation purposes. While the Endangered Species Act prohibits keeping endangered species in captivity for display purposes, rehab animals may be displayed to enhance recovery of the species, provided the display does not interfere with their treatment and eventual release back into the wild.

One of the four, named Comet, was released at Blue Springs in Florida in March 2000. He was initially brought in as the dependent calf of a critically-injured mother who died of as a result of boat-related injuries. Sea World of Florida nursed him through his initial separation and started the long process of _growing him out‘. Rehabilitators keep small, orphaned manatees in captivity until they are big enough to fend for themselves. Columbus Zoo finished the process, and plans were made for his release when he met health and size standards and demonstrated an ability to feed on plants found in natural habitats. He was about eight and a half feet long and weighed 925 pounds [2.6 m and 420 kg] at release.

The success of Comet‘s reintroduction to the wild has been carefully monitored by means of a satellite tag, which provides locations, water temperatures, and a sense of the animal‘s well-being. U.S. Geological Service biologists and Florida State Park Service staff coordinate the field monitoring efforts. Based on the latest updates, Comet appears to be adjusting well. Columbus Zoo‘s involvement in manatee conservation efforts is an important one. The zoo‘s role as educators and rehabilitators enhances federal, state and private partnership efforts toward recovery of this endangered species, and provides additional support for critical rescue and research initiatives.

James A. Valade in The Conservationist Vol. 5, No. 1 (July 2000)

 

Denver Zoo, Colorado, U.S.A.

Snakes present an incredible variety of food preferences and solutions to the problems of dining without limbs. The 3,000-plus species of snake range from generalists, who will eat almost anything they can overpower and swallow, to hundreds of specialists that may eat only one type of animal and sometimes only a single species. Among the generalists are whipsnakes and racers, most cobras, and some of the Australian elapid snakes; most of these will eat any lizard, snake, frog, bird or mammal that they can catch and swallow. Naturally most of these species do not present much of a dietary challenge to anyone maintaining them in captivity. It is among those species that specialize in one type of prey that we find the source of most headaches in feeding captive snakes. Some of the more interesting specialists are found in the United States. Hog-nosed snakes (Heterodon spp.) feed nearly exclusively on toads and can rarely be induced to eat even a leopard frog. Rainbow and mud snakes (Farancia spp.) feed entirely on the long, legless amphibians known as sirens and Congo eels (neither from the Congo nor eels, they are large eel-shaped amphibians, Amphiuma spp., from the south-eastern U.S.). Scarlet snakes (Cemophora coccinea) may eat only the eggs of other reptiles.

Many tropical snakes, some of which we display in Denver‘s Tropical Discovery, have even more bizarre feeding specializations. African egg -eating snakes (Dasypeltis spp.) eat only eggs of the appropriate size and incubation state. They swallow these intact, then regurgitate the shell after it has been broken in the esophagus by the protruding spines of the neck vertebrae. Two species of venomous sea snake (Emydocephalus annulatus and E. ijimae) will eat only the eggs of a few species of fish. There are snail-eating snakes (Dipsas spp.) with specialized teeth and lower jaws for removing the molluscs from their shells, and arboreal lizard-eaters (Dryophis and Oxybelis spp.) with specialized eyes giving binocular vision for tracking their fast-moving prey.

All snakes have an organ of smell (the Jacobson‘s organ) in the roof of the mouth. The tongue transfers odor particles to this sensitive organ and this allows the snakes to recognize specific prey organisms and to reject others. Because mice and rats are commercially bred and seem to be a better and more parasite-free food source than wild-caught frogs, lizards and snakes, zoo professionals make great efforts to get all snakes feeding on mice and rats. Reptile keepers have shown considerable inventiveness in attempting to overcome some of these feeding specializations and to keep snakes of species whose preferred diet is difficult or impossible to provide. King cobras (Ophiophagus hannah) are exclusively snake-eaters in the wild, and this makes them difficult captives as each specimen requires a large supply of live snakes. We have been successful in training them to take rodents by taking small sections of frozen snakes and sewing them with surgical gut to two or three dead rats. The cobras will start swallowing the snake piece, then be forced to take the rats because they are attached. They try to wipe off the rats but eventually will swallow them. Some learn to eat rodents without the piece of snake; but, interestingly, they are never able to modify their swallowing mechanism, which only works well with snake prey, to the classical jaw movements that all rodent-eaters employ. Either they have structural differences in their jaws, or their swallowing behavior is so _hard-wired‘ that they cannot adjust it.

There are many small arboreal lizard-eating snakes on display in Tropical Discovery. One of the most beautiful is the paradise flying snake (Chrysopelea paradisi) from Indonesia. These usually have to be started feeding by offering them live lizards; but soon they will take dead lizards, then dead lizards with a small dead mouse sewn to them. Eventually they become familiar enough with the odor of the mouse that they will take mice from forceps.

Small, wild-caught eyelash vipers (Bothriechis schlegeli) often prefer frogs. Amphibians usually have very distinctive skin slime that can be rubbed onto a mouse which is then offered to the snake. Usually one frozen frog will be sufficient to scent dozens of mice, and eventually the snake will shift to rodent feeding.

All of the above techniques involve subverting the snake‘s olfactory sense that is telling it that an item is or is not an appropriate prey item. Sometimes we can utilize the snake‘s stereotypic behavior chains to get a specimen to eat something it otherwise wouldn‘t. Most vipers and pit vipers eat rodent prey in the wild, but are sometimes difficult to get started feeding in captivity because of their nervousness or the unavailability of the exact species they prefer. Knowledge of their feeding behavior gives us an advantage in dealing with these snakes. Typically, they are _sit and wait‘ predators that detect a live rodent walking by, strike and envenomate it, and then release it to run off and die. They do this because rodents are very dangerous to try to hold until they are dead. After a few minutes the snake begins tongue-flicking to locate the trail by smell. It then follows the scent trail to the dead rodent and swallow it. In captivity, the viper may not recognize the species of rodent offered, and thus refuses to strike at it. Often we can take a dead laboratory mouse that the viper refuses to strike at, wave it threateningly in front of the snake with forceps, and get the snake to strike defensively, as it would at a predator. This appears to trigger the whole stereotypic behavior chain, and the snake will then begin tongue-flicking and searching for the mouse. Upon finding it, the snake will eat it, even though it had rejected that species earlier.

Constrictors have a similar stereotypic behavior chain involving grabbing the prey, constricting and killing it, finding the head and swallowing. Again we can sometimes break into this chain in the middle and get it to go to completion, with the snake eating a prey item it would normally refuse. If the keeper uses forceps to wriggle a dead rodent in the body coils of a constrictor, the snake will often begin what appears to be involuntary twitching. Persistence with the rodent will cause the snake to begin to constrict its prey, followed by eating it.

Utilizing these various tricks that take advantage of the snakes‘ stereotypic behaviors and ability to be gradually trained to different odors have allowed zoos to be successful with species that would not have survived in captivity a generation ago. Maybe if we can become still more creative in our approach to feeding, the world of snakes specializing in things like centipedes, scorpions, slugs and frog eggs will also become open to us.

Charlie Radcliffe, Area Supervisor of Fishes and Reptiles, in The Zoo Review (Summer 2000)

 

Edinburgh Zoo, U.K.

In 1994, Edinburgh was the first zoo in Britain to breed the Egyptian spiny-tailed lizard (Uromastyx aegyptius), and four years later we were delighted to see the second generation hatch successfully, which was possibly a world first. Because they are so endangered in the wild, all 15 species of Uromastyx are listed under Appendix II of CITES, and the European Union has a current ban on importation from the wild. These lizards have always had a poor record in captivity, being somewhat infamous for their refusal to feed, eventually succumbing to a lingering death. So we were very pleased when we were able to demonstrate that, with a bit of effort, this species can not only be maintained but bred to second generation.

The successful maintenance of U. aegyptius in captivity is reliant on an understanding of their natural history. They inhabit the dry rocky desert areas of Egypt, Sudan, Syria, and the Arabian Peninsula through to western Iraq. This is a truly desert species and, as such, is adapted to live in one of the harshest environments in the world. They can withstand a great range of temperatures, from mid-day highs of well over 50° C to night lows which can drop to 0° C by excavating long, deep burrows where they maintain the temperature at around 20° C. They can also endure long periods of drought, as they derive most of their fluid requirements through their diet, which is primarily vegetation.

Accommodation should be spacious, as these lizards are, as a rule, an active species and can be highly territorial. The exhibit we use for our adult group measures 4 ´ 3 ´ 2 m and simulates a desert environment, incorporating a substrate of coarse sand to a depth of 15 cm. Sandstone boulders create a rocky outcrop and sand-coloured paving slabs which sit on buried bricks are provided to act as retreats for the lizards. It is important that heavy objects such as boulders are cemented down, as this species will undermine them, being a habitual burrower, and this can lead to unnecessary accidents.

They have massive appetites and require feeding almost every day. We try to offer as much in the way of wild greens as is feasible, but our individuals also have a great liking for insects, in particular locusts, crickets and waxworms, and these are offered occasionally as a nutritional stimulus.

Both males and females are highly territorial during the breeding season, which here lasts from March through June, and careful observation is needed to identify animals being dominated to the point where they will no longer emerge from their tunnels to feed. If this does occur, the individual in question will have to be removed until breeding behaviour ceases within the group. Males are territorial of the entire exhibit, whereas females are territorial of their respective tunnels. Male aggression is predominantly directed towards other sexually active males, and although these bouts of wrestling, with occasional smacks with the tail, rarely lead to injury, they can take precedence over mating, so it is recommended that only one male is maintained with the females, and that spare males are passed through to stimulate the territory-holder should he become complacent toward his _harem‘.

Female aggression, however, is somewhat more complicated and can lead to the suppression of all other females in the group. In our experience, the dominant female is always the aggressor, and she will defend her chosen tunnel violently. This is why it is so important to have an appropriate number of tunnels available to all specimens – during the breeding season, each female, whether dominant or subordinate, gravid or non-gravid, will require her own tunnel, as shared accommodation will not be tolerated. But outside the breeding season the females are entirely tolerant of each other and will share their tunnels with other individuals.

The male instigates courtship by approaching a female and repeatedly bowing his head. He will then proceed to walk in a circular motion over her, rubbing his cloaca over her back, sometimes depositing small amounts of uric acid. Matings are generally short in duration. On a number of occasions females have been observed lying on their backs with the male astride them, a behaviour which has also been reported at Indianapolis Zoo. This appears to indicate a reluctance on the female‘s part to be mated. The male will bite the female above the shoulder and attempt to mate with her, but she, instead of raising her tail, will start to twist and spin until he releases his grip. She will then lie upside down until he moves away. When a female is willing to be mated, she is passive when grasped by the male.

Once gravid, females become very aggressive towards others in the group and highly possessive of their chosen tunnel. The female will gradually become more rotund, and when walking on raised legs the stomach sometimes drags along the ground. Approximately one week prior to egg deposition she will excavate every corner of the exhibit, but she will invariably lay the eggs in her chosen tunnel. It is important that the sand is kept slightly dampened during this period, as females will lay only in a damp substrate.

Our females typically lay around 17 eggs, though one female laid 21 in 1998. Eggs of this species are somewhat more delicate than most other reptile eggs, as the shell is less _parchment‘ and more _tissue paper‘ in texture and frailty. This may well be an adaptation to the dry, harsh environment in which they have to develop, where even the slightest amount of moisture has to be absorbed to enable continued development.

The eggs are relatively large, averaging 5.1 ´ 2.7 cm. Viable eggs have a visible pink area on their upper surface, which is indicative of an already developing embryo and is a good indicator of the polar position when removing eggs from the nest site and setting up for incubation.

The best substrate for incubation is a mixture of dry coarse sand and wet vermiculite in a ratio of 10:1. The eggs will not succeed if the substrate is too wet or too dry. We therefore have to find the balance between the two, and this mixture – at a depth of at least 3 cm – gives us good results. The eggs are set up in a plastic box container, the lid of which has a small hole punched into each corner The eggs are placed into a depression to about one-third of their depth.

We then incubate them, using a second-hand hospital _child type‘ incubator, set for a constant 28.5° C, though a range of 28–30° C is probably adequate for this species. It is essential to maintain a very high level of humidity in the incubator, c. 75%. Eggs which fail during incubation develop an unmistakable odour and need to be discarded before the inevitable bacterial and fungal growths develop, which could possibly affect other eggs. The duration of the incubation period is naturally temperature-dependent, with hatching occurring between 88 and 105 days.

Douglas Sherriff in Arkfile Vol. 9, No. 3 (Autumn 2000)

 

Heritage Park Zoo, Prescott, Arizona, U.S.A.

Olfactory enrichment is the most challenging work for our enrichment team, and until recently the least successful. Unknowingly, we were missing a very special ingredient, a scent that would create a significant response in animals. At the 1999 AAZK conference in Portland, Oregon, a paper presented from Disney‘s Animal Kingdom, Florida, mentioned the use of a perfume known as _Angelfire‘ (distributed by Mary Kay Cosmetics), which had an intoxicating effect on their six female tigers. We decided to try this substance on some of our cats.

Armed with spray bottles of diluted Angelfire and cameras for documentation, we headed for Shikar, a male Bengal tiger. Previously, rope was wrapped around his favorite tree, to encourage clawing, face-rubbing and scent-marking. The enrichment team sprayed the rope with perfume and introduced a small tire, also scented, as a novelty toy. The test was planned at feeding time to make it easier for the keepers as well as more accessible to the team. Shikar consumed part of his meal, but then, to our amazement, caught the scent of Angelfire and immediately demonstrated flehmen. He straddled the roped tree, rubbing his face and body as if in abandoned ecstasy. The scented tire was next; he tossed it in the air, rolled around, and licked it. He seemed as if transformed into a cub.

Inca, the jaguar, one of our most difficult cats to enrich, was our next test case. The vertical pole in his enclosure was also wrapped with rope. This seemed the obvious target for Angelfire. The consensus was that the perfume probably wouldn‘t cause a reaction in this independent cat, for food was his passion. We were wrong. He got a whiff of his pole and mounted it with sheer delight. Witnessed by the enrichment team and the keepers, he proceeded to drool long ropes of saliva as he embraced the pole with a flehmen grimace on his face. Eventually, he grew tired of being the centre of attention and resumed eating. But who would have thought that a scent designed for humans could have such a profound effect on our wild zoo cats!

Adapted from Linda Kocar in Animal Keepers‘ Forum Vol. 27, No. 8 (August 2000)

 

John G. Shedd Aquarium, Chicago, Illinois, U.S.A.

Many of the newest animals in the Fishes Department aren‘t fishes, only a few have scales, and a couple can‘t even swim. They are the semi- or non-aquatic species now on show in the aquarium‘s _Amazon Rising: Seasons of the River‘ exhibit, and they include pygmy marmosets, a two-toed sloth, an emerald tree boa and a green anaconda. But whether these animals spend part of the time in water or all of the time in trees, they are representative residents of the Amazon flooded forest ecosystem, where the distance between river and canopy is sometimes only a matter of feet.

The Amazon flooded forest is one of the most diverse ecosystems on earth. It supports more fish species than any other freshwater system – about 2,000 identified and possibly many more new species in regions still to study – as well as scores of reptiles, hundreds of birds and millions of invertebrate species. Amazon Rising, with 250 kinds of animals, offers a sample of this complexity to illustrate how each species both depends on and supports the other animals and plants around it.

If the composition of the Amazon Rising habitats is more complex than that of previous exhibits, so is the job of caring for all this new biological diversity. Even though the two pygmy marmosets were born and raised at Lincoln Park Zoo and not the western Amazon, U.S. Department of Agriculture rules required that they undergo a 60-day quarantine. _New World monkeys are susceptible to human cold viruses as well as tuberculosis,‘ says Allen Feldman, curator of fishes. _All the employees who work with marmosets have to be tested for TB. And if a staff member has a cold or the flu, that person does not approach the animals.‘ When in doubt, aquarists wear surgical face-masks to safeguard the little monkeys‘ health. _It‘s different from what we‘re used to with fishes,‘ says Feldman, _but it‘s common practice in zoos with primates.‘

Aquarium staff have designed a behavioral enrichment program which helps provide stimuli similar to what the marmosets would encounter in the wild. The monkeys are also involved in a training program similar to the one for the marine mammals. They are learning to _target‘, which involves recognizing an object that can be used to guide or lead the animal through behaviors. Targeting is especially useful in teaching an animal to move from one part of its habitat to another for an examination. Fishes Department staff have participated in training programs themselves to learn more about the mammals and other animals new to the aquarium. The Marine Mammals staff held a husbandry training seminar for Fishes personnel, and colleagues at other zoological institutions have shared their time and knowledge with Shedd‘s aquarists.

Senior aquarist Jim Watson traveled to the Bronx Zoo to spend several days working with its large snakes. He observed how keepers fed, cleaned and maneuvered the anacondas and other big boas, and then described Shedd‘s exhibit habitats – a floating meadow for the anaconda, a tree canopy for the emerald tree boa – and asked zoo staff how they would deal with various situations. Back at Shedd, he trained other aquarists in the art of caring for big snakes. At about six feet and nine pounds [1.8 m and 4 kg], the aquarium‘s young female green anaconda is growing steadily, gaining four pounds [1.8 kg] between her January and May physical examinations. Most herpetologists consider 26 feet and 400 pounds [8 m and 180 kg] to be the maximum size for this species. The aquarium intentionally acquired a small anaconda, says Watson. _With an animal that will get very large, it‘s better to get a young specimen that you can work with to get it used to people. It‘s also easier to start the husbandry staff working with a smaller animal than with a full-grown adult. It gives them a chance to grow up with the snake.‘

Abridged from Karen Furnweger in WaterShedd Vol. 21, No. 3 (Summer 2000)

 

Monkey World, Dorset, U.K.

On 19 July 2000, the first shipment of confiscated apes arrived at Monkey World from Pingtung Rescue Centre for Endangered Animals in southern Taiwan. The shipment included a female orang-utan named RoRo and eight gibbons. These individuals were chosen for the first group as they passed two rigorous health checks and were fit for the long journey. All the apes shared the same tragic story. They were born in the wild, had their mothers shot from underneath them, and were smuggled into Taiwan for the illegal pet trade. The authorities finally confiscated all of them apes from people‘s homes in Taiwan.

We estimate that RoRo is approximately ten years old and came from Borneo. The gibbons came from various parts of South-East Asia and include: 3.1 Mueller‘s gibbons from Borneo (one of the males is missing his left arm above the elbow); one male agile gibbon who could have come from the Malay Peninsula, Sumatra, or Borneo; one male lar gibbon who could have come from China, Thailand, Laos, Burma, the Malay Peninsula or Sumatra; and two female concolor gibbons from Laos, Vietnam, or Cambodia.

The rescue centre [see I.Z.N. 45:2, pp. 71–77 – Ed.] was set up by the Taiwanese authorities in 1993 to provide temporary accommodation for confiscated wild animals that had been smuggled into the country illegally. The smuggling started after 1986, when a television programme called The Naughty Family featured an orang-utan as a family pet. Soon everyone wanted an exotic pet and the market in these endangered primates went wild. As babies, the orang-utans were cute and could be kept in a house like a human baby, but in order to catch them the mothers had to be killed and the clinging babies removed from their chests. It is a very traumatic and bloody process and the babies often die while being captured or subsequently. For every orang-utan who made it to Taiwan alive it is estimated that five died in the process.

In 1989 the Taiwanese authorities passed a wildlife conservation law prohibiting people keeping exotic animals as pets.; owners were given a period of six months to register their animals in order to be exempt from future penalties. From this point on, officials confiscated any wild animals unless they had been registered. Enforcement has been so successful that Pingtung is now full to capacity. Monkey World is helping by providing a home for the healthy gibbons and orang-utans at the centre. We are expecting that more individuals will clear their health checks shortly, and hope to bring more Asian apes to Dorset by the end of the year.

Ape Rescue Chronicle No. 15 (Summer 2000)

 

Monterey Bay Aquarium, California, U.S.A.

Beyond the humane and practical issues that drive most decisions to respond to marine mammal strandings, program managers must place rehabilitation efforts in a proper context. With that objective in mind, the aquarium‘s Sea Otter Research and Conservation (SORAC) program tries to position its activities within the larger context of southern sea otter (Enhydra lutris nereis) recovery, thus forming linkages to relevant issues involving the species.

After years of modest growth, the population of southern sea otters in California‘s coastal waters has declined by approximately 12% over the past four years. In response, SORAC program staff have shifted their emphasis to place the continued survival of the subspecies as their foremost guiding principle. SORAC collaborates with various partners to monitor population status, understand the causes of high mortality, maximize survival and reintroduction of live-stranded sea otters, and establish contingencies against a continuing population decline. We continually seek the integration of rehabilitation, research, and management activities in everything we do. By undertaking rehabilitation work, we develop expertise that overlaps a broad range of research and conservation challenges. Without the veterinary skills, animal handling skills, field support and tracking we provide, a number of field research projects would probably not be underway.

The SORAC program rescues and rehabilitates sea otters of all ages with the aim of returning them to the wild. Over the past 15 years, the aquarium‘s staff and veterinarians have developed diets and care protocols that have resulted in a high survival rate for live-stranded pups, juveniles, and adults. Since 1984, we have recovered and treated nearly 200 sea otters. By handling living animals, better care and management techniques emerge, trends in disease become apparent, possible intervention measures surface, and we reintroduce healthy animals that contribute to the wild population.

We believe that long-term monitoring of released animals is necessary to determine whether rehabilitation techniques yield positive results. Before release, we equip each otter with color-coded flipper tags, and implant all young otters with a VHF transmitter. We track these animals for up to two years to evaluate their progress, and re-capture those otters that fail to demonstrate adequate survival skills for transfer to other aquariums for long-term care. (Ironically, because the Marine Mammal Protection Act prohibits the display of listed species, the otters‘ _threatened‘ status actually interferes with placing non-releasable animals in zoos and aquariums. We are working with the U.S. Fish and Wildlife Service on a permit plan that should resolve this issue.)

All southern sea otters in zoos and aquariums originally came through SORAC‘s rehabilitation program; thus, we feel a strong sense of responsibility for coordinating a management strategy for institutions holding non-releasable otters for public display. This SSP-like strategy is crucial for improving programs for general care, breeding, cooperative research and rehabilitation.

Recently, the SORAC program realized a long-anticipated goal. On or about 16 November 1999, an otter rehabilitated and released in 1997 delivered a healthy pup in the wild. As we monitor the physical and behavioral development of this pup, we find ourselves again shifting the contextual basis upon which we operate our rehabilitation program. Fifteen years ago, we felt satisfied keeping a sea otter pup alive. Now, nothing short of a successful release and integration into the wild population will suffice. With each new milestone, we must revise our definitions of success.

Abridged from Andrew B. Johnson, Program Manager, Sea Otter Research and Conservation, in AZA Communiqué (March 2000)

 

Riga Zoo, Latvia

The zoo‘s Ecological Laboratory was founded in 1988 as part of a project to restore the European tree frog (Hyla arborea) to Latvia. Ten years later this project was successfully completed, though regular monitoring of the reintroduced population will continue. Meanwhile, the laboratory had begun to breed many other amphibian species. The 2000 season was very successful, and almost all the species of exotic amphibians kept in our collection were bred. Among them, such rare species as Theloderma corticale [see I.Z.N. 46:6, pp. 347–352 – Ed.] and Bufo galeatus, as well as Scynax rubra, ornate horned frog (Ceratophrys ornata), tomato frog (Dyscophus antongilii), White‘s tree frog (Litoria caerulea), Asian tree frog (Polypedates leucomystax), and three species of poison-arrow frog (Dendrobates azureus, D. auratus and D. tinctorius), have bred regularly for several years. This summer Dyscophus guineti and Leptodactylus insularum decided to follow the good example of others and bred for the first time. Fire-bellied toads (Bombina bombina) bred in the exhibition of Latvian native amphibians.

We were able to collect plenty of interesting data about our amphibians, because all the cases of breeding and the tadpoles‘ and froglets‘ development are well documented. Special attention is paid to data about T. corticale and P. leucomystax, and we hope to solve the problem of why we have so many males and so few females among the frogs we have raised. The information we have collected will also help us to design the new exhibition of exotic amphibians in the zoo‘s planned Tropical House.

Ilze Dunce

 

Riverbanks Zoological Park, Columbia, South Carolina, U.S.A.

The following births and hatchings took place during the period July to September 2000: 1 pink-necked fruit dove, 1 keel-billed toucan, 3 Gould‘s monitor, 1 bog turtle, 4 spotted turtle, 8 black-headed python, 1 crocodile skink, 11 eastern diamond-backed rattlesnake, 4 lined leaf-tailed gecko, 24 Henkel‘s leaf-tailed gecko, 5 giant leaf-tailed gecko, 2 giant day gecko, 2 chuckwalla.

The following were acquired: 0.1 blue-crowned motmot, 2.1 king cobra, 1 copperhead, 4.4 blue poison-dart frog, 1 scrawled cowfish, 1 yellow stingray, 1 occelated moray, 2 painted greenling, 10 black-eye goby, 2 rock beauty angelfish, 2 pygmy angelfish, 1 white-spotted filefish, 1 scrawled filefish, 1 queen angelfish, 8 porkfish, 10 French grunt, 6 cottonwick grunt, 1 giant Pacific octopus, 3 painted tealia, 3 white-spotted tealia, 3 fish-eating tealia, 2 pincushion urchin, 6 diadema sea urchin, 3 banded coral shrimp, 36 camel shrimp, 144 Trochus snail, 50 Turbo snail.

Working with the South Carolina Department of Natural Resources and the S.C. Native Plant Society, Riverbanks Zoo is restoring the rocky shoals spider lily (Hymenocallis coronaria). The lily makes its home on rocky outcrops along rivers. The foliage emerges in spring and the white blooms tend to appear in June. Changes in river flow, among other factors, have made this lily increasingly rare in South Carolina. Zoo horticulturists are cultivating seeds gathered in the wild, mostly along the Broad River in the Columbia area. The seedlings from the zoo‘s Growing Center are then returned to the wild. The horticulture staff are also experimenting with other ways to reproduce the plant through vegetative propagation. While seen as a supplement rather than a replacement to seedling reproduction, vegetative reproduction offers hope for greater availability of the plant to its native habitat and to the public.

Alan H. Shoemaker, Collection Manager (births and acquisitions), and AZA Communiqué (July 2000) (rocky shoals spider lily)

 

Ueno Zoo, Tokyo, Japan

The zoo has ten (2.8) pancake tortoises (Malacochersus tornieri). They have laid eggs every year since 1997, but at first none hatched. They are kept on a substrate of sand, which is lightly misted once a day. Usually the females dig a nest in the sand and bury their eggs, but sometimes they just lay an egg on the surface. To keep the eggs from being trampled, all are collected and put in an incubator. The eggs are white and measure about 44 by 30 mm. Usually only one egg is laid at a time. Some eggs that were laid in December 1998 hatched in June 1999. Other eggs laid in March and April 1999 hatched in September or October that year, bringing the total number of hatchlings to seven. One died at the age of eight months, but all the others are developing normally.

The eggs took 140–220 days to hatch, an average of 184 days. Humidity was kept at 60–70%, and the temperature was set at either 28° or 30° C. The eggs kept at 28° C took a little longer to hatch. The hatchlings had voracious appetites, and one began eating leafy vegetables on the day it emerged. Some emerged with the yolk sac already completely gone, but others took up to a week to absorb it. Adults show almost no need for water, but the hatchlings not only drank but also sought out damp spots to rest in. When furnished with a shallow vessel of water, they entered it frequently.

The hatchlings‘ weight and carapace length were measured nearly every week. Just after hatching, they weighed about 14 grams, about 3% of the adult weight, but they gained weight very rapidly after that. After 12 weeks individual differences in growth began to appear. Adult males are smaller than females and weigh about 20% less. The differing weight gains of the hatchlings may be due to sex differences. Immediately after hatching the carapace was wider than long, and the body thickness was similar to that of other tortoises, but after six weeks the carapace became longer than broad, and the babies took on the flattened form typical of the species.

English summary of article in Japanese by Yuki Takahara, published in Animals and Zoos Vol. 52, No. 8 (August 2000)

 

Wildfowl and Wetlands Trust, Martin Mere, Lancashire, U.K.

Two new exhibits have been completed during the year. The first was our Sustainable Garden, which aims to demonstrate ways in which we can garden on a more environmentally-friendly basis, using less water by planting drought-resistant species and utilising mulches. A solar pump is used to create moving water, and other features include an insulated greenhouse, fruit cage, wormery, compost area and nature garden. There is a display of different types of nest box and bat box.

The second exhibit completed this year was an African Water-hole housing grey-necked crowned crane, comb duck, white-faced whistling duck and Egyptian goose. The cranes represent something of a new departure for Martin Mere and their dancing has proved very popular with the public.

It has been a very odd year from the point of view of breeding, particularly in the two flamingo flocks. Greater flamingos laid two infertile eggs in March and did not lay again until two eggs were produced in August. Our greaters have consistently produced eggs every year since 1990 with a peak in April and May, so this year‘s results are rather peculiar. Our Chilean flock also did not lay until August, when they produced 20 eggs, several nests containing two eggs. A pair of magpie geese also produced a trio of eggs in August. Other notable hatchings were goosander, Patagonian crested duck, bronzewing, marbled duck, cereopsis, lesser Magellan goose, and coscoroba and black-necked swans.

The centre received a Commendation from the Federation of Zoological Gardens of Great Britain and Ireland for its conservation work with wild tree sparrows (Passer montanus), a species which has declined seriously in Britain in recent years.

P.J. Wisniewski

* * *

RECENT ARTICLES

 

Aden, D.: Expanding beyond captive care giver to captive manager: my role as studbook keeper and population manager for pygmy marmosets (Callithrix pygmaea). Proceedings, 26th AAZK National Conference (1999), pp. 7–12.

Alink, R.: We hid our zoo in a wildlife refuge! Proceedings, 26th AAZK National Conference (1999), pp. 52–53. [Wildlife West Nature Park, New Mexico; attracting native wildlife.]

Andra, K.: Keeper involvement in research at White Oak Conservation Center. Proceedings, 26th AAZK National Conference (1999), pp. 13–18. [A behavioural and reproductive study of the okapi.]

Baker, K.C.: Advanced age influences chimpanzee behavior in small social groups. Zoo Biology Vol. 19, No. 2 (2000), pp. 111–119. [Management strategies for captive chimpanzees must begin to take into account the increasing age of the captive population. Data were collected on 14 old individuals (30–44 years old) and 20 younger adult individuals (11–22 years old) at Yerkes Regional Primate Research Center. In the same captive setting, the behavior of old chimpanzees was significantly different from that of younger animals. Old chimpanzees showed less aggression and moved about their enclosures less. Old females behaved submissively more often than younger adult females; the reverse was found among males. However, affiliative social behavior occurred at similar levels in old and younger adults, implying continued need for social housing with advancing age. These results suggest that aging in chimpanzees may be accompanied by altered patterns of social interaction, requiring careful attention to the compatibility of social partners. Also, old chimpanzees manipulated objects and/or their enclosures less, which may influence the success of some enrichment devices for aged individuals.]

Baker, W.K.: Are there any special precautions that should be considered before going into the field, especially in other countries? Animal Keepers‘ Forum Vol. 27, No. 8 (2000), pp. 346–347.

Baker, W.K.: What should I expect when a crisis occurs? Animal Keepers‘ Forum Vol. 27, No. 6 (2000), pp. 250–252.

Baker, W.K.: What technical aspects should you look for in a cat management facility? Animal Keepers‘ Forum Vol. 27, No. 7 (2000), pp. 294–296.

Berghaier, R., Maas-Anger, T., and Ffinch, J.: Wild avifauna of the Philadelphia Zoological Garden. Animal Keepers‘ Forum Vol. 27, No. 7 (2000), pp. 316–324.

Bocian, D.: Comparison of exhibit use and social behavior of resident and introduced female Francois langurs (Presbytis f. francoisi). Proceedings, 26th AAZK National Conference (1999), pp. 63–71. [San Francisco Zoo, California. To assess whether an adult female François‘s langur could be successfully introduced to a group of six animals (consisting of an adult male, two adult females, and their offspring), 52 hours of systematic social behavior, exhibit use, and proximity data was collected using the three adult females as focals. The new female‘s behavior was compared to that of resident females as an evaluation of her integration into the troop. The adult male exhibited positive interactions with the new female, while the resident adult females were moderately agonistic but quickly allowed the new female to rest with troop members and engage in social grooming. The concurrent fall in rank of two post-partum females (one resident and the new female) suggests that rank in females is variable. Results indicate that the addition of the new female to the stable existing troop was not disruptive.]

Cantrell, R., Chag, M., Cooke, C., and Pope, B.: Introduction and acclimation of two species of Old World fruit bats to the _Cliffs of Anandapur‘: a free flight exhibit at Disney‘s Animal Kingdom. Proceedings, 26th AAZK National Conference (1999), pp. 91–100. [Malayan flying fox (Pteropus vampyrus) and Rodrigues fruit bat (P. rodricensis).]

Cassinello, J., and Pieters, I.: Multi-male captive groups of endangered dama gazelle: social rank, aggression, and enclosure effects. Zoo Biology Vol. 19, No. 2 (2000), pp. 121–129. [A study of four multi-male groups of captive dama gazelles (Gazella dama mhorr) at the Estación Experimental de Zonas Aridas, Almería, Spain, characterized the social rank order of males and possible enclosure effects on aggression rate. A strong relationship between rank and age was found. The results also showed that dominant individuals in the two smallest enclosures were more aggressive than their herdmates, suggesting a more stressful environment, which might precipitate unstable or challenged hierarchies when the animals live in a more restricted enclosure. Subordinate males performed submissive responses at a higher frequency, irrespective of the size of the enclosure. The frequency of interactions between the gazelles, on the other hand, was affected by enclosure size, since high-ranking males showed higher values than low-ranking males in the two smallest enclosures. Frequencies of aggressive acts, retreats, and related interactions were similar in all the herds. Implications for the management of the species in captivity are discussed.]

Chester, M.: Keeping Indian scops owls. Tyto Vol. 5, No. 3 (2000), pp. 134–137. [Otus bakkamoena.]

Dieckmann, R., Pagel, T., and Wolters, J.: Der Regenwald – ein neuartiges Tropenhaus im Kölner Zoo. (Cologne Zoo‘s new Rainforest tropical house.) Zeitschrift des Kölner Zoo Vol. 43, No. 2 (1999), pp. 55–69. [German, with brief English summary.]

Fritz, J.: I‘m forever blowing bubbles! The Newsletter Vol. 11, No. 3 (2000), pp. 1–2. [Soap bubbles as environmental enrichment for chimpanzees.]

Guerrero, D.: Animal behavior concerns and solutions: a clicker training program for American black bears. Animal Keepers‘ Forum Vol. 27, No. 7 (2000), pp. 290–292.

Guerrero, D.: Animal behavior concerns and solutions: camel training questions. Animal Keepers‘ Forum Vol. 27, No. 8 (2000), pp. 339–341.

Guerrero, D.: Animal behavior concerns and solutions: guidelines regarding parrot training. Animal Keepers‘ Forum Vol. 27, No. 6 (2000), pp. 258–261.

Haddad, J.A.: _Drop chute‘ restraint - an alternative to chemical immobilization at the San Diego Wild Animal Park. Proceedings, 26th AAZK National Conference (1999), pp. 83–86.

Hawkins, J.P., Roberts, C.M., and Clark, V.: The threatened status of restricted-range coral reef fish species. Animal Conservation Vol. 3, No. 1 (2000), pp. 81–88. [Throughout the world, coral reefs are being overfished, polluted and destroyed. To date, much of the concern over the resulting biodiversity loss has centred on local losses, and the possibility of global extinction has largely been discounted. However, recent research has shown that 24% of reef fish species have restricted ranges (< 800,000 km2), with 9% highly restricted (< 50,000 km2). Restricted-range species are thought to face a greater risk of extinction than more widespread species, since local impacts could cause global loss. The authors searched for information on status in the wild and characteristics of 397 restricted-range reef fish species, and compared body size, habitat requirements and usefulness to people with those of a taxonomically-matched sample of more widespread species. They found that on average species with restricted ranges were significantly smaller, tended to have narrower habitat requirements and were less used by people. Greater habitat specificity will tend to increase extinction risk, whereas, if real, more limited usefulness may reduce risk. Fifty-eight percent of restricted-range species were considered common/abundant in the wild and 42% uncommon/rare. Population status and threats to 319 species for which data were available were assessed according to the IUCN categories and criteria. A number of species were found to be rare, were exploited and had highly restricted ranges overlapping areas where reef degradation is particularly severe, placing them at a high risk of extinction. Five species were listed as Critically Endangered, two of them (the wrasse Anampses viridis and the damselfish Azurina eupalama) possibly already extinct in the wild, one as Endangered and 172 as Vulnerable. A further 126 species fell into Lower Risk categories and 11 were considered Data Deficient. Given the intensity of impacts to reefs, the broad geographical areas affected and the large numbers of restricted-range species, global extinctions seem likely. Urgent management action is now crucial for the survival of several species of reef fishes.]

Heuschkel, B., Kröhne, A., and Zimmermann, W.: Die Haltung von Junggesellengruppen für das EEP – Grevyzebras im Kölner Zoo. (Cologne Zoo‘s bachelor group of Grevy‘s zebras.) Zeitschrift des Kölner Zoo Vol. 42, No. 3 (1999), pp. 103–120. [German, with English summary (see above, pp. 460–462).]

Hoppes, R.E., Lyon, E., Rudovsky, M., Engeszer, S., and Willers, C.: Evolution of keeper interpretive programs at the San Francisco Zoo. Proceedings, 26th AAZK National Conference (1999), pp. 119–123.

Houts, L.: Utilizing young visitors for behavioral enrichment. Proceedings, 26th AAZK National Conference (1999), pp. 72–73. [Folsom City Zoo, California.]

Kalla, J., and Sevenich, M.: Managing hoofed stock at Disney‘s Animal Kingdom and Disney‘s Animal Kingdom Lodge. Proceedings, 26th AAZK National Conference (1999), pp. 142–151.

Kastelein, R.A., Schooneman, N.M., Vaughan, N., and Wiepkema, P.R.: Food consumption and growth of California sea lions (Zalophus c. californianus). Zoo Biology Vol. 19, No. 2 (2000), pp. 143–159. [The daily food consumption of 26 sea lions at Harderwijk Marine Mammal Park, The Netherlands, was recorded. Average annual food consumption of males increased with age to stabilize at approximately 4,000 kg/year by the age of ten years. Females showed a rapid increase in average annual food consumption until they were three years old. Thereafter, females housed outdoors averaged 1,800 kg/year, whereas those housed indoors ate approximately 1,400 kg/year. Between the ages of four and seven, the food intake of males began to fluctuate seasonally, decreasing between May and August. The low food intake in summer was associated with an increase in aggressive behavior. Seasonal fluctuation in the food intake of non-reproductive females was negligible. Between the ages of six and eight years, many females began to reproduce successfully. Pups were born in May and June. The females‘ food intake decreased approximately three days before birth and ceased the next day. Feeding resumed the day after birth, and by two days after birth it had usually returned to normal. On average, female intake increased in the year of conception, the year of birth, during which the pup was suckled for six months, and the following calendar year, during which the pup was weaned. Pups began to eat fish at approximately 11 months of age, and when force-fed they were fully weaned within two to 23 days. Male weight and body length increased until approximately 20 years of age. Females increased in body length until six years and in weight until approximately 13 years of age. The relationship between standard body length and body weight is given. The heavier an animal is, the lower is its food intake as a percentage of body weight.]

Kastelein, R.A., van der Elst, C.A., Tennant, H.K., and Wiepkema, P.R.: Food consumption and growth of a female dusky dolphin (Lagenorhynchus obscurus). Zoo Biology Vol. 19, No. 2 (2000), pp. 131–142. [Data on food consumption, body measurements, weight changes and body temperatures are presented for the 13 years that the dolphin was at Sea World, Durban, South Africa.]

Kornak, A.M.: The success of performing procedures using operant conditioning with giraffe in a restraint device. Proceedings, 26th AAZK National Conference (1999), pp. 124–128. [Binder Park Zoo, Michigan.]

Lantermann, W.: Lebensraumbereicherung und Beschäftigungsförderung für Papageien in Menschenobhut. (Environmental and behavioural enrichment for captive parrots.) Zeitschrift des Kölner Zoo Vol. 43, No. 3 (2000), pp. 129–137. [German, with very brief English summary.]

Laubscher, C.: Cloncurry parakeets – a review of this fascinating species. Parrot Society Magazine Vol. 34, No. 8 (2000), pp. 266–268. [Barnardius b. macgillivrayi.]

Laubscher, C.: Rock pebblers – a golden gem from the south of Australia. Parrot Society Magazine Vol. 34, No. 8 (2000), pp. 264–265. [Polytelis anthopeplus.]

Lockwood, J.L., Brooks, T.M., and McKinney, M.L.: Taxonomic homogenization of the global avifauna. Animal Conservation Vol. 3, No. 1 (2000), pp. 27–35. [Several authors have suggested that in order for conservation to become more proactive, taxonomic or phylogenetic information can be used as a triage tool. Evolution probably conserves particular traits within phylogenetic units, such as families. The result is an increase in susceptibility of species in these groups to invasiveness or extinction compared to species within other groups. By clearly identifying these groups, we can proactively place species at the top of either our red-lists (i.e. prevent extinction) or our black-lists (i.e. prevent invasion). The results of the present study confirm the existence of taxonomic patterns in extinction risk and probability of successful introduction, and suggest that species-poor families are taxonomically favoured for extinction. The combined effects of taxonomic selectivity for extinction and successful introduction could leave a future avifauna with far fewer species and fewer higher taxa. Several bird families are at high risk of extinction (e.g. Procellariidae, Rallidae). With a few minority exceptions (e.g. Passeridae, Tyrannidae), the species that survive the effects of taxonomic homogenization will mostly be remnants – those few species from formerly large families that we inadvertently selected to coexist with us in urban habitats. This future scenario is probably not confined to birds.]

Low, R.: Breeding Amazona brasiliensis in Brazil. Parrot Society Magazine Vol. 34, No. 8 (2000), pp. 253–255.

Malina, C.: Interpreting and influencing animal behavior: an essential keeper‘s tool. Proceedings, 26th AAZK National Conference (1999), pp. 129–135. [Natural Encounters, Inc., Orlando, Florida; operant conditioning and positive reinforcement training.]

Neptune, D., and Larsen, E.: Multi-male bisexual entellus langur troop: it can be done! Proceedings, 26th AAZK National Conference (1999), pp. 101–108. [Utah‘s Hogle Zoo, Salt Lake City. The zoo has exhibited an intact troop of entellus langurs (Presbytis entellus thersites) since 1990. Following a recommendation from the langur studbook keeper in the fall of 1997, the authors began to assess the possible introduction of an additional, solitary male to the all-adult troop, consisting of one male and three females. Attempts to introduce this new male with other males at previous institutions had been unsuccessful. Studies show that breeding populations typically consist of one adult male, several females and their offspring. Male offspring emigrate, frequently forming all-male bands. Dispersal of the all-male bands can result in multi-male breeding troops. These studies have shown a high rate of antagonistic behavior between the resident male and the migrant male. This often results in the expulsion of the resident male, and the troop is then restored to uni-male status. The migrant male will exhibit aggression towards the females as well. Due to this natural behavior, attempts to introduce a second adult male to a bisexual troop at zoos have not been successful, so little information is available on multi-male bisexual troops in captivity. In the present case, a twelve-month process resulted in the successful introduction of the new male. Key factors in this success included the use of a sedative to decrease the males‘ anxiety and aggression, the fact that the resident male had been castrated (following a TAG-recommended moratorium on breeding in this species), and the fact that the introduction took place in an enclosure which was unfamiliar to all the animals.]

Neu, K., Howell, S., Fritz, J., and Murphy, J.: Rigid plastic balls as environmental enrichment: a novel presentation. The Newsletter Vol. 11, No. 2 (2000), pp. 1–2. [A way of encouraging positive social interaction between chimpanzees in adjacent cages.]

Ohlinger, R., Schwandt, M., Fritz, J., and Howell, S.: King Kong® rubber toys: an effective enrichment device for captive chimpanzees (Pan troglodytes). The Newsletter Vol. 11, No. 2 (2000), pp. 2–4.

Palmer, B.: The lemurs are loose: Project Betampona, Madagascar – black and white ruffed lemurs return to the wild. Proceedings, 26th AAZK National Conference (1999), pp. 57–62.

Pastorello, L.: Mixed species exhibits by animal choice. Proceedings, 26th AAZK National Conference (1999), pp. 109–111. [The Zoo, Gulf Breeze, Florida, has a 30-acre (12 ha) preserve housing 35 free-ranging species of hoofstock and birds. The author describes interactions between these animals and the chimpanzees, gorillas and colobus on islands in an adjacent lake.]

Pratte, J.: Creating habitats from a whole lotta‘ nothin‘. Proceedings, 26th AAZK National Conference (1999), pp. 47–51. [Little Rock Zoo, Arkansas; low-cost rehabilitation of sterile, old-fashioned exhibits using volunteer keeper labour.]

Prutzman, D.: A new, dynamic live food presentation to captive wolves. Proceedings, 26th AAZK National Conference (1999), pp. 74–75. [Grizzly Discovery Center, Montana. Live rats are released in the 0.8 ha enclosure, with a system of plastic tunnels which gives them some chance of survival (during a ten-week period, 40 out of 50 rats were caught).]

Pywell, M.: The use of environmental enrichment in pinnipeds. Animal Keepers‘ Forum Vol. 27, No. 6 (2000), pp. 276–278.

Reed, D.H., and Bryant, E.H.: Experimental tests of minimum viable population size. Animal Conservation Vol. 3, No. 1 (2000), pp. 7–14. [Fitness and rates of extinction were compared among populations of the housefly ( Musca domestica), kept either at constant effective sizes of 50, 500 or 1500 or passed through extreme founder events reducing effective size to 5. Populations were maintained for 24 generations, which for small- to medium-sized mammals would be less than the 200 years frequently regarded as necessary for maintaining viable populations of endangered species. The results demonstrate that effective population sizes have to be greater than the 50 individuals sometimes suggested in order to retain fitness and escape extinction, even in the short term. In contrast to populations of constant size that exhibited monotonic decreases in fitness through time, populations established with few founders rebounded from initial inbreeding depression. However, they were less adaptable to environmental stress than constant-size populations, suggesting that populations founded with few numbers may do well within a single environment but may do far less well if they are reintroduced to natural environments or exposed to rapid environmental changes.]

Rice, A., Wright, R., Hilton, S., and Floyd, S.: Reintroduction of a hand-raised infant bonobo (Pan paniscus) to her biological parents and sibling. Proceedings, 26th AAZK National Conference (1999), pp. 29–37. [Jacksonville Zoo, Florida.]

Robertia, J.: A year in the life – a photographic study of horn growth and chromatic development in the pelage of bontebok (Damaliscus d. dorcas) calves. Proceedings, 26th AAZK National Conference (1999), pp. 170–179. [Dallas Zoo, Texas.]

Ross, J.P.: From art to science: documenting the effectiveness of enrichment and training. Proceedings, 26th AAZK National Conference (1999), pp. 76–82. [Disney‘s Animal Kingdom, Florida; parrots and parma wallabies.]

Schireman, M.R.: The history of a mixed species exhibit: its failures and successes. Proceedings, 26th AAZK National Conference (1999), pp. 112–118. [Oregon Zoo, Portland; the species involved at various stages were Cape clawless otter, L‘Hoest‘s monkey, Kikuyu colobus and Allen‘s swamp monkey.]

Schultz, C.A.: Show and husbandry training considerations for the binturong (Arctictis binturong). Proceedings, 26th AAZK National Conference (1999), pp. 152–61. [Disney‘s Animal Kingdom, Florida.]

Silver, S.C., Ostro, L.E.T., Yeager, C.P., and Dierenfeld, E.S.: Phytochemical and mineral components of foods consumed by black howler monkeys (Alouatta pigra) at two sites in Belize. Zoo Biology Vol. 19, No. 2 (2000), pp. 95–109. [The authors analyzed the chemical composition of the diets of eight groups of free-ranging monkeys in two different forests. Young and mature leaves, fruits, flowers and fig samples were analyzed, and statistically significant differences were found in almost all measures. However, when two of the study groups were translocated from one forest to the other three months into the study, it was found that they compensated for changes in nutrient availability by concentrating on different plant parts. This confirms a high degree of behavioral and dietary flexibility for this species, and suggests that howler monkeys may be excellent candidates for translocation, even to areas with completely different types and levels of resource abundance. Data from the study may also be useful in developing optimal diets for captive howler monkeys.]

Tardona, D.R., and Tardona, J.H.: Primate food sharing behavior and its relationship to panhandling in captivity. Animal Keepers‘ Forum Vol. 27, No. 6 (2000), pp. 269–273. [_Panhandling‘ (begging for food from visitors) in captive primates is a development of a natural behaviour reinforced by some features of the zoo environment.]

Templeton, M., and Sevenich, M.: Tiger training at Disney‘s Animal Kingdom: husbandry and enrichment and its role in guest experience. Proceedings, 26th AAZK National Conference (1999), pp. 137–141.

Thomas, K.: The successful hand rearing and reintroduction of a Saudi goitered gazelle. Proceedings, 26th AAZK National Conference (1999), pp. 38–46. [Detroit Zoo, Michigan; Gazella subgutturosa marica. (Also published in Animal Keepers‘ Forum Vol. 27, No. 7 (2000), pp. 309–315.)]

Tkachuk, G.: The hand-rearing and reintroduction of Chip and Dale. Proceedings, 26th AAZK National Conference (1999), pp. 162–169. [Valley Zoo, Edmonton, Canada; cotton-top tamarin.]

Unger, R.: Anmerkungen zur Handaufzucht von Kurzohr-Rüsselspringern, Macroscelides proboscideus (Shaw, 1800). (Notes on hand-rearing of short-eared elephant shrews.) Zeitschrift des Kölner Zoo Vol. 43, No. 3 (2000), pp. 121–126. [German, with English summary. The author, at Schönbrunn Zoo, Austria, reared two litters, both of which were separated from their mother immediately after birth. They were kept in a plastic box (50 ´ 50 cm) on a substrate of sand, with hiding places and an infra-red heating source. The young were fed with a kitten milk-replacer supplemented with lactic acid bacteria. This milk substitute was fed in a 1:1 dilution with fennel tea, the latter being reduced step by step, until on the sixth day milk was fed undiluted. Feeding took place with the first litter every three, with the second litter every four hours with 2-ml and later 5-ml one-way squirts. The change to solid food took place with the first litter on the 7th and 8th day, by adding baby pap to the milk and offering solid food, a fine mixture of cucumber, carrot, apple, curd and moist cat food ad libitum. With the second litter no baby pap was added to the milk, and solid food was offered on the 7th day. On the 8th and 9th days respectively the feeding of milk was stopped. The report subsequently describes the behaviour of the young until the 14th and 25th days respectively; this does not differ in any way from the behaviour of adults of the species.]

Urban, R., Arnold, P., and Wilkes, C.: A look into the nestbox of the rhinoceros hornbills at the Houston Zoo. Proceedings, 26th AAZK National Conference (1999), pp. 87–90. [Buceros rhinoceros silvestris; monitoring with a light-sensitive camera.]

Wagner, D.C., and Edwards, M.S.: Hand-rearing black and white rhinoceros: a comparison. Proceedings, 26th AAZK National Conference (1999), pp. 19–28. [San Diego Wild Animal Park. No significant differences were found in hand-rearing the two species. The authors stress the importance of providing companion animals to reduce dependence of the calves on their human caregivers; a domestic goat, an eland and several species of wild cattle were used for this purpose.]

Wensing, J.: Burgers‘ Bush – der Versuch, ein Ökosystem zu präsentieren. (Burgers‘ Bush, Arnhem, the Netherlands – an attempt to present an ecosystem.) Zeitschrift des Kölner Zoo Vol. 43, No. 2 (2000), pp. 93–99. [German, with brief English summary. The aim of the 1.5-ha Bush, opened in 1988, was to establish an ecosystem similar to that of a tropical rainforest. Plants and animals should coexist with as little human intervention as possible. The soil of the Bush is very poor, consisting of rough sand covered by a layer of fallen leaves and bark. The plants chosen were a mixture of fast- and slow-growing species. Pest control is achieved by means of natural predators, or by parasites of the pest itself.]

Whitney, T.K., Brader, F., and Horlock, M.A.: Color discrimination match-to-sample tasks as behavioral enrichment for a Yucatan miniature pig. Animal Keepers‘ Forum Vol. 27, No. 7 (2000), pp. 297–300.

Wilkinson, D.L.: An introduction of lemurs and flying foxes at Crystal Garden Conservation Center. Animal Keepers‘ Forum Vol. 27, No. 8 (2000), pp. 361–364. [Victoria, British Columbia, Canada. A successful mixed exhibit was created with ring-tailed and ruffed lemurs and Indian flying fox (eventually to be replaced with Rodrigues fruit bats).]

Womack, J.: Raising parent-reared kori bustard at the Dallas Zoo. Animal Keepers‘ Forum Vol. 27, No. 8 (2000), pp. 359–360. [Dallas Zoo is the only institution in the western hemisphere known to have successfully produced parent-reared kori bustards (Ardeotis kori). The author attributes their success to several factors. First, the breeding group is kept in an off-exhibit area with no visitor traffic and limited staff traffic. Secondly, as the breeding season starts, they allow the vegetation in the birds‘ pens to overgrow. This growth gives the females many places to hide and may add to their feeling of security. Next, the pop-gates and access to several yards gives each female a territory and a safe place to get away from each other and the males. And finally, at the hatching of any chick all other birds are removed from the yard, and access thorough the pop-gates is stopped. Kori bustards are predatory in the wild, and the possibility exists that other adults might eat a new chick.]

Publishers of the periodicals listed:

Animal Conservation, Zoological Society of London, Regent‘s Park, London NW1 4RY, U.K.

Animal Keepers‘ Forum, American Association of Zoo Keepers, 3601 S.W. 29th Street, Suite 133, Topeka, Kansas 66614, U.S.A.

The Newsletter, Primate Foundation of Arizona, P.O. Box 20027, Mesa, Arizona 85277–0027, U.S.A.

Parrot Society Magazine, Parrot Society, 108b Fenlake Road, Bedford MK42 0EU, U.K.

Proceedings of the 26th National Conference of the American Association of Zoo Keepers, Inc., A.A.Z.K., 3601 S.W. 29th Street, Suite 133, Topeka, Kansas 66614, U.S.A.

Tyto, International Owl Society, Sheraton Lodge, Station Road, Southminster, Essex CM0 7EW, U.K.

Zeitschrift des Kölner Zoo, Zoologischer Garten, Riehler Strasse 173, D-50735 Köln, Germany.

Zoo Biology, John Wiley & Sons, Inc., 605 Third Avenue, New York, NY 10158, U.S.A.