UNGULATES 117

Int. Zoo Yb. (1993) 32 117-124 0 The Zoological Society of London

Conservation assessment and management plan for antelope KAREN A. SAUSMAN Executive Director, The Living Desert, 47-900 Portola Avenue, Palm Desert, California 92260, USA

The Captive Breeding Specialist Group of the IUCN/SSC has begun the develop- ment of Conservation Assessment and Management Plans (CAMPs) and Global Captive Action Plans (GCAPs) for a variety of taxonomic groups including hornbills, carnivores and rhinoceroses (Foose & Seal, 1992).

The CAMP process reviews the wild and captive status of all taxa in the group under consideration, on a taxon by taxon basis, assesses the degree of threat for each taxon in the wild and recommends levels of intensive action that may reduce the risks for threatened taxa, especially management involving the captive community. The recommendations for intensive management are provided for use by managers of both wild and captive populations.

The CAMPs are being used to test the applicability of the Mace/Lande criteria for assessment of threat in terms of like- lihood of extinction within a specific period of time (Mace & Lande, 1991). This system is still under active development.

The proposed Mace/Lande system defines three categories for threatened taxa: 1 . Critical, 50% probability of extinction within 5 years or two generations, which- ever is longer; 2. Endangered, 20% probability of extinction within 20 years or ten genera- tions, whichever is longer; 3. Vulnerable, 10% probability of extinc- tion within 100 years.

The GCAPs specifically relate the CAMPs to captive populations and what the captive community could and should attempt to contribute to the intensive management needs of threatened taxa. Where captive programmes are recom- mended, there is an attempt to propose the level of captive programme required to reflect the taxa’s status and prospects in the wild. To date, GCAPs have targeted six levels of captive programmes: 1. 90%/100 years I, population sufficient to preserve 90% of the average hetero- zygosity of the wild gene pool for 100 years, developed as soon as possible (1-5 years); 2. 90%/100 years 11, population sufficient to preserve 90% of I:he average hetero- zygosity of the wild gene pool for 100 years but developed more gradually (5-10 years); 3. Nucleus 1, a captive nucleus (50-100 individuals) to alway:~ represent 98% of the wild gene pool. This type of pro- gramme will require periodic but, in most cases, modest immigration to maintain this high level of genetic diversity in such a limited captive population; 4. Nucleus 11, a well-managed captive nucleus (25-100) for taxa not of conserva- tion concern but present in captivity or otherwise of interest; 5. Elimination or no captive breeding, taxa are not of concern and captive popu- lation should be managed to extinction; 6 . Husbandry purposes only, breed for experience in c,aptive management only.

I18

DEVELOPMENT OF THE ANTELOPE CONSERVATION AND MANAGEMENT PLAN There are approximately 90 species of antelopes within the family Bovidae. Most of the species are found in Africa and the Middle East, with a few forms further east in Asia. They live in various habitats including mountains, deserts, tropical rain forests and jungles. Antelope range in size from the Giant eland Tragelaphus der- biunus, shoulder height 100&1800 mm, to the Dik-dik Mudoqua sp, shoulder height 305405 mm, and Bates’ dwarf antelope Neotragus batesi, shoulder height c. 355mm (Nowak & Paradiso, 1983). Some forms, such as the vast herds of Wildebeest Connochaetes sp, are still common and appear to be holding their own in the wild while others have either become extinct in the wild or are now balanced precariously on the edge of extinction. Habitat loss and hunting, both for sport and food, have been major factors in the decline of many populations.

A complete review of the status of ante- lope was undertaken by the Antelope Specialist Group of IUCN/SSC as a first step in the development of a global strategy for their conservation. Three of the four Global Surveys and Regional Action Plans for Antelope compiled by Rod East have been published, covering Africa south of the Sahara (East, 1988, 1989, 1990). An action plan for Duikers Cephalophus sp has also been published (Wilson, 1987). Much of the information concerning the status of the wild popula- tions of the various taxa in this report has been drawn directly from these important publications.

In 1989, the author developed the first in a series of surveys of all Artiodactyls in captivity (Sausman, 1989a, 1990, 1991) which included a review of over 600 taxa, their status in the wild, numbers in cap- tivity, current captive programmes, avail- able space in captivity and other relevant information. The CBSG Artiodactyl Working Group assigned captive pro-

gramme priority levels to over 125 taxa. These early surveys and captive breeding priority lists were used as the basis for the development of a more complete review of the antelopes (Sausman, 1989b; Seal et ul., 1990).

The current CBSG Antelope Working Group, chaired by the author, has active members from the IUCN Antelope Specialist Group, the American, British, European, African, Australian and Gulf States regional antelope management groups, and the Veterinary Specialist Group. In January 1992, members of the working group and the Antelope Specialist Group, including Dr Ulysses Seal, Chairman of the IUCN/CBSG, Dr Richard Estes, Chairman of the IUCN/ASG, and Dr Rod East, compiler of the Global Surveys and Regional Action Plans for Antelope, met in Palm Desert, California, to develop a first draft of an Antelope CAMP. By March 1992, the first draft was completed and circu- lated to the workshop participants whose comments, along with those of AAZPA’s Antelope Taxon Advisory Group, were incorporated into a second draft. The second draft was reviewed by original working group members as well as indivi- duals who attended a second CBSG Ante- lope Working Group meeting held in South Africa in June 1992 (J. L. Ander- son, pers. comm.). Copies were also circu- lated at a meeting hosted in October 1992, in Riyadh, Saudi Arabia, by the National Commission for Wildlife Conservation and Development of Saudi Arabia on ‘Establishing priorities for gazelle conser- vation in the Arabian peninsula’.

Integral to the development of the Antelope CAMP was a review of the taxonomy of this group of bovids. The working taxonomic list recognizes ten subfamilies and is generally based on the ASG Action Plans and on Ansell (1971). For some groups, for example, gazelles, dwarf antelopes and duikers, taxonomy at the species level is still open to review. It is probable that many of the described subs- pecies of antelope may reflect individual

UNGULATES I19

variation and even when real taxonomic variations are reflected, there is insuffi- cient information to determine precise distributional limits of many subspecies. The worksheets developed by the Group list recognized subspecies, including many which are not held in captivity, to provide a relatively complete framework for plan- ning captive breeding and future accessions.

ANTELOPE CONSERVATION AND CAPTIVE PROGRAMME RECOMMENDATIONS Of the 395 antelope taxa listed in the June 1992 Antelope CAMP, 135 are currently held in captivity in numbers ranging from a few individuals to thousands. The working group reviewed all 395 taxa using the Mace/Lande criteria to assign a degree of threat to 166 forms: critical, 11; endan- gered, 19; vulnerable 1, 25; vulnerable 2, 21; not of concern/safe, 90 (Table 1). The category ‘vulnerable 2’ was added to meet a level of concern that the original Mace/ Lande scale did not address: vulnerable 2 species do not yet meet the criteria for vulnerable but are likely to do so within the next few decades.

East (1992) noted that ‘Application of the Mace/Lande criteria to African ante- lopes suggests that relatively few species are endangered or critical at present, but this situation could change dramatically within the next 100 years. Human popula- tion growth is the fundamental cause of most current and potential loss of bio- diversity. In the case of African antelopes, increasing numbers of people, expansion of settlement, greater numbers of live- stock, loss of habitat and over-hunting inevitably lead to the eventual loss of most species in the absence of effective conservation measures.’

The percentage of antelope species at risk as a factor of the human population per square kilometre has been plotted against the level of protection and management provided in the region (East, 1992). It is clear that as human popula- tion densities rise the number of species which are endangered also rises, parti-

cularly in those countries where there are no protected areas. Current growth rates of human populations in most sub- Saharan African countries are within the range of 2.5-3.5% a year. Within 100 years, almost all of i.hese countries will have human population densities suffi- ciently high to place rn ost antelope species at risk unless there are well-managed conservation areas. Some species of ante- lope, such as Wildebeest and Lechwe Kobus sp, tend to be dominant members of their herbivore community and have a major impact on other associated ante- lopes and on the whole ecosystem (Estes, 1992), so the welfare of the whole commu- nity may depend on maintaining large populations of these ‘Ikeystone’ species.

These concerns along with other rele- vant current population and status reports from scientists working in the field, led the working group to accept the fact that the degree of threat to many species must still be open to re-evaluation as more information becomes available.

In addition to making specific recom- mendations for each taxa, the working group determined there were some general needs for the conservation of antelopes and gazelles. One important consideration is the taxonomic uncertainty of many forms and so, where appropriate, taxo- nomic surveys, including both cytogenetic and molecular genetics, should be conducted for identification of subspecies or other evolutionary significant units. This is needed particularly within the genus Gazella and in 1 he duikers. Recent advances in the application of genetic techniques can help to substantiate and clarify taxonomic confusion. With the development of gene tic laboratories in Kenya and South Africa, this process will become easier and be of direct benefit particularly to in situ conservation programmes.

The working group considers that many species which are vulnerable or critical would benefit from more intensive in situ management and the establishment of protected areas. Indeed, even those

120

SPECIES: SUBSPECIES CAPTIVE RECOMMEND.

CRITICAL Mountain nyala

Tragelaphus huxtoni Aders’ duiker

Cephalophus adersi Aders’ duiker (Zanzibar pop.)

Cephalophus adersi Giant sable antelope

Hippotragus niger variani Scimitar-horned oryx

Oryx dammah Arabian oryx

Oryx leucor>.u Addax

Addax nasomaculatus Swayne’s hartebeest

Alcelaphus buselaphus swayner Acacia gazelle

Gazella gazella acaciae Muscat gazelle

G. g. muscatensis Saudi gazelle

Ga;ella saudiya

ENDAKGERED Jentink’s duiker

Cephalophus jentinki Ruwenzori red duiker Cephalophus nigrifrons rubidus

Western mountain reedbuck Redunca fulvorufula adamauae

Baker’s roan antelope Hippotragus equinus bakeri

East African sable antelope Hippotragus niger roosevelti

Tord hartebeest Alcelaphus buselaphus tora

Hunter’s antelope or Hirola Damaliscus hunteri

Western klipspringer Oreotragus 0. porteousi

Black-faced impala Aepyceros melampus petersi

Yemen gazelle Gazella bilkis

Cuvier’s gazelle Gazella cuvieri

Darna gazelle Gazella darna

Mhorr gazelle G. d. mhorr

Addra or Kordofan gazelle G. d. ruficollis

Rio de Oro dorcas gazelle Gazella dorcas neglecta

Farasan Island gazelle Gazella gazella farasani

Slender-horned gazelle Gazella leptoceros

90%/100 I

90%/100 I

90%/100 I

90%/100 I

90%/100 1

9OYo/lOO I

90%/100 I

90%/lOO 1

9O%/lOO I

90%/100 1

90%/100 I

90%/100 I

90X/l00 I

90%/lOO I

90%/lOO I

90%/100 I

9OX/lOO I

90%/100 I

90%/100 I

90%/l00 I

90%/100 I

90%/100 I

90%/100 1

90%/100 I

90%/100 I

90%/100 I

NUC I

90%/100 I

SPECIES/SUBSPECIES

~~ ~~~~~~~~ ~~ ~ ~~

Arabian goitred or Sand gazelle Gazella subgut rurosa marica

Mongolian saiga antelope Saixa tatarica mongolieu

VULNERABLE 1 Western giant eland

Tragelaphus d. derhianus Eastern bongo

Tragelaphus euryceros isuuc I Four-horned antelope

Tetracerus quadricorni.? White-legged duiker

Cephalophus ogilbyi crusalhum Abbott’s duiker

Cephalophus spadix Zebra duiker

Cephalophus zebra Chanler’s mountain reedbuck

Redunca fulvorufula chanleri Angolan roan antelope

Hippotragus equinus cortoni Black or White-tailed wildebeest

Connochuetes gnou Kenya hartebeest hybrid Alcelaphus buselaphus cokei x A . b. lelwel

Bontebok Damaliscus d. d0rca.s

Korrigum Damaliscus lunatus korrigum

Piacentini’s dik-dik Madoqua piacentinii

Beira antelope Dorcatragus megalotis

Haggard’s oribi Ourebia 0. haggardi

Dibatag Ammodorcas clarkei

Pelzeln’s gazelle Gazella dorcas pelzelni

Mountain gazelle Gazella gazella

Palestine mountain gazelle Gazella g . gazella

Arabian gazelle G. g. cora

Heuglin’s gazelle Gazella rujifrons tilonura

Soemmerring’s gazelle Gazella soemmerringii

Dahlac gazelle Guzella soemmerringii ssp indet

Speke’s gazelle Gazella spekei

Przewalski’s gazelle Procapra przewalskii

90%) 100 I 1

90%’l00 I

90% 100 I

YlJC I I

90% 100 I 1

90% 100 I I

90% 100 I

90% 100 I

90% 100 I

90% 100 I1

9OYo 100 11

none

90% 100 I

90% 100 1

h U C I

NUC I

90% 100 11

90% 100 11

90% 100 11

see subspp

NCJC I

90% 100 I1

90% 100 11

90% 100 I1

90% 100 I1

90%/ 100 I1

UNGULATES 121

SPECIES/SUBSPECIES CAPTIVE RECOMMEND.

SPECIES/SUBSPECIES CAPTIVE RECOMMEND.

VULNERABLE 2 Giant eland

Trugeluphus derbiunus Eastern giant eland

T. d. gigus East African sitatunga

Trugeluphus s. spekii Harvey’s red duiker

Cephulophus hurveyi Black duiker Cephulophus niger

Ogilby’s duiker Cephulophus ogilbyi

Defassa waterbuck Kobus ellipsiprymnus defussu

Red lechwe Kobus 1. leche

Black lechwe K. 1. smithemuni

Kafue lechwe K. 1. kufuensis

Nile lechwe Kobus meguceros

Puku Kobus vardoni

Beisa oryx Oryx guzellu beisu

Fringe-eared oryx 0. g. callotis

Lichtenstein’s hartebeest Alceluphus lichtensteinii

Tsessebe Dumuliscus 1. lunutus

Royal antelope Neotragus pygmaeus

Blackbuck antelope Antilope cervicupru

Bennett’s or Chinkara gazelle Guzella bennetti

Dorcas gazelle Guzella dorcus

Red-fronted gazelle Guzellu rufifrons

NOT OF CONCERNiSAFE

Trugeluphus ungusii

Trugeluphus scriptus

T. s. scriptus

Trugeluphus spekii

T. s. grutus

T. s. selousi

Lowland nyala

Bushbuck

Western bushbuck

Sitatunga

West African sitatunga

Southern sitatunga

see subspp

90%/lOO I1

NUC I

NUC I1

90%/lOO 11

90%/100 I1

NUC I1

90%/100 I1

90%/100 I1

90%/100 I1

90%/100 I1

9 O X / l O O I1

NUC I

NUC I

NUC I

90%/100 I1

NUC I1

NUC I1

NUC I

NUC I

NUC I

NUC I1

no cap. br.

no cap. br.

NUC I1

NUC I1

NUC I1

Lesser kudu Trageluphus imberbis

Southern lesser kudu T. i. australis

Greater kudu Trugeluphus strepsiceros

South African greater kudu T. s. strepsiceros

Bongo Trugeluphus euryceros

Western bongo T. e. euryceros

Common eland Trageluphus oryx

Cape eland T. 0. oryx

Zambesi eland T. 0. livingstonii

East African eland T. 0. puttersoniunus

Nilgai Boseluphus trugocumelus

Peters’ duiker Cephulophus cullipygus

Bay duiker Cephulophus dorsulis

White-bellied duiker Cephulophus leucogaster

Maxwell’s duiker Cephulophus muxwellii

Blue duiker Cephulophus monticolu

Red forest or Natal duiker Cephalophus natalensis

Black-fronted duiker Cephalophus nigrifrons

Red-flanked duiker Cephulophus rufilutus

Yellow-backed duiker Cephalophus sylvicultor

Weyns duiker Cephulophus weynsi

Grey or Crowned duiker Sylvicapru grimmiu

Waterbuck Kobus ellipsiprymnus

South ellipsen waterbuck K. e. ellipsiprymnus

Lake Victoria defassa watertiuck K. e. ado@-friderici

Kob Kobus kob

Buffon’s kob K. k . kob

White-eared kob K. k . leucotis

Uganda kob K. k. thomusi

NUC I1

NUC I1

NUC I1

NUC I1

NUC I1

NUC I1

NUC I1

NUC I1

NUC I1

NUC I1

NUC I1

NUC I1

husb. purp.

no cap. br.

husb. purp.

husb. purp.

NUC I1

NUC I1

NUC I1

NUC I1

no cap. br.

no cap. br.

NUC I1

NUC I1

NUC I1

see subspp

NUC I1

NUC I1

NUC I

122

SPECIES/SUBSPECIES

Lechwc Kobus leche

Southern reedbuck Redunca arundinum

Mountain reedbuck Redunca fulvorufula

South African mountain reedbuck R . f fulvorufula

Bohor reedbuck Redunca reduncu

Grey rhebok Pelea capreolus

Roan antelope Hippotragus equinus

East African roan antelope H. e. langheldi

Sable antelope Hippotragus niger

South African sable antelope H . n. niger

Gemsbok Orys g. gazella

Blue or Brindled wildebeest Connochaetes taurinus

~~

Southern wildebeest or Brindled gnu I

C. t . taurinus Eastern white-bearded wildebeest

C. t . albojubatus Cookson’s wildebeest

C. t . cooksoni Nyassa or Johnston’s wildebeest C. 1. johnstoni

Western white-bearded wildebeest C. t . mearnsi (hecki)

Common hartebeest Alcelaphus buselaphus

Red or Cape hartebeest A . 6 . caama

Coke’s or Kongoni hartebeest A . h. cokei

Lelwel hartebeest A . b. lelwel

Western hartebeest A. 6. major

Bontebok Damaliscus dorcas

Blesbok D. d. phillipsi

Topi or Tsessebe Damaliscus lunatus

Jimela topi D. 1. jimelu

Tiang D. I . tiang

Coastal topi D. 1. topi

Klipspringer Oreotragus oreotragus

CAPTIVE RECOMMEND.

~~

see subspp

NUC 11

see subspp

NUC 1

NUC 11

NUC 11

NUC 11

NUC J

NUC 11

NUC I1

NUC I1

see subspp

NUC I1

NUC 11

no cap. br.

no cap. br.

NUC I1

see subspp

NUC I

NUC I

NUC I

NUC I

see subsp

NUC I1

see subspp

NUC I

NUC I1

NUC I1

NUC I1

SPECIES/SUBSPECIES

Guenther’s dik-dik Madoqua guentheri

Kirk’s dik-dik Madoqua kirki

Damara dik-dik M . k . damarensis

Salt’s dik-dik Mudoqua saltianu

Oribi Ourehia ourebi

Bates’ dwarf antelope Neotragus batesi

Suni antelope Neotragus moscharu.c

Zanzibar suni N . m. moschatus

Steenbok Raphicerus campesrris

Cape grysbok Raphicerus melanotis

Sharpe’s grysbok Raphicerus sharper

Impala Aepyceros me1ampu.r

Transvaal impala A . m . melampus

Kenyan impala A. m. rendilis

Springbok Ant idorcas marsupiali.r

Gerenuk Litocranius wnlleri

Grant’s gazelle Gazella granti

Goitred gazelle Gazella subgutturnxi

Thomson’s gazelle Gazella thomsonii

Kilimanjaro Thomson’s gazelle G. t . thomsonii

Mongalla gazelle G. t . albanotata

Mongolian (zeren) gazelle Procapra gutturosa

Tibetan (goa) gazelle Procapra picticaudatu

Tibetan antelope Pan tholops hodgson i

Saiga antelope Saiga tatarica

Russian saiga antelope S. t. tatarica

CAPTIVE RFCOMMEVL)

UUC I1

NUC I 1

no cap br

no cdp br

NUC I 1

no cap br

NUC I1

\uc 11

no cap br

Y U C I1

no Cdp br

NUC 11

h U C I1

N U C 11

YUC IT

N U C I1

N U C I1

NUC I1

no cap br

NUC I1

NUC I1

Y U C I1

NUC I1

YUC I1

\ee subspp

YUC I I

Table 1. Antelope taxa by the Mace/Lande category system with captive management recommendations.

UNGULATES 123

MACE/LANDE CAPTIVE MANAGEMENT RECOMMENDATIONS CATEGORY

TOTAL NO. SPECIES

90?'0/100 I 90?'0/100 11 NUCLEUS I NUCLEUS 11 NO CAPTIVE HUSBANDRY BREEDING PURPOSES

CRITICAL 1 1 11 ENDANGERED 17 1 1 19 VULNERABLE 1 6 12 3 1 22 VULNERABLE 2 9 I 4 20 NOT OF CONCERN 8 58 13 3 82

TOTAL NO. SPECIES 34 22 19 63 13 3

Table 2. The numbers of species and subspecies in each of the six levels of the Global Captive Action Plan captive management programmes compared with the Mace/Lande categories. The numbers here do not include forms which have not been assigned captive management recommendations even though they are included in various Mace/Lande categories (see Table 1).

species which have reasonably large popu- lations at this time, may have most of the population located outside protected areas and may be under continued pressure from habitat loss.

Many of the lesser known species of antelopes and gazelles which are critically endangered are not found in captivity and efforts should be made to establish captive 'buffer' populations for these species. The precise origin of all wild-caught indivi- duals must be documented at the time these animals are brought into captivity. Studbooks should be started for any species which is recommended for any level of captive management in the Global Action Plan. It is possible that specimens of some critical species may exist in zoos or private collections in their country of origin and it is urgent that such collec- tions be identified and encouraged to participate in the captive management of these species.

For many taxa, husbandry problems need to be identified and protocols estab- lished. Isolated captive management problems for some species continue to surface and these may reflect inappro- priate husbandry practices and/or genetic compromise. For small antelope such as duikers, research is needed on their social structure, life history and nutritional requirements in order to manage better

the captive populations of this increas- ingly endangered taxa.

For virtually all of the antelope and gazelle species which are declining or criti- cally endangered, the major problems tend to be either hahitat loss or over- hunting. For desert species, habitat loss has been exasperated by the prolonged drought in many areas. Small antelopes are under constant pressure of subsistence hunting.

As habitats continue to be lost and species whose populations were once large and continuous become fragmented into isolated remnant populations, there will be a need to evaluate ithe effects of isola- tion on the health of the individual popu- lations and the species as a whole. On the positive side, sufficient numbers of some critical species exist in captivity to make replenishment and/or reintroduction possible. Efforts should be made to co- operate with local government in deve- loping viable reintroduction programmes.

Of the 395 taxa listed in the Antelope CAMP, over 200 have been left without formal comment at this time. Most of these forms are subspecies for which no scientifically useful information on status in the wild is available. In some cases these are questionable taxonomic forms. The working group generally followed the lead of the Antelope Specialist Group in

124

recognizing subspecies for assigning degrees of threat and making captive breeding recommendations.

The Antelope Working Group welcomes comments on the material presented here. We recognize these lists will undergo several more modifications as more information comes to light or, 'sadly', as situations in the wild continue to deteriorate.

ACKhOWLEDGEMENTS

The development of a Conservation Assessment and Management Plan for a group of animals as diverse as antelopes and gazelles is certainly not the task of a single individual. The number of people who have given generously of their time and information are too numerous to mention. Certain people, though, have played extraordinary roles in the CAMP process. In particular, I would like to thank Terrie Correll, Dr James Dolan, Dr Richard Estes, Dr Rod East, Tom Foose, Dr Arnaud Greth, Larry Kilmar, Bruce Read, Dr Ullyses Seal, Ed Spevak and, also, my secretary Angela Woods, for her efforts in bringing the reports into publishable form.

REFERENCES ANSELL, W. F. H. (1971): Order artiodactyla. In The mammals of Africa: an identification manual part 15: 1-84. Meester, J. I% Setzer, H. W. (Eds). Washington, DC: Smithsonian Institution Press. EAST, R. (1988): Antelopes. Global survey and regional action plans. Part 1. East and northeast Africa. Gland: IUCNjSSC Antelope Specialist Group. EAST, R. (1989): Antelopes. Global survey and regional action plans. Part 2. Southern and south- centrul Africa. Gland: IUCN/SSC Antelope Specialist Group. EAST, R. (1990): Antelopes. Global survey and regional action plans. Part 3 . West and central Africa. Gland: IUCNjSSC Antelope Specialist Group.

EAST, R. (1992): Conservation status of antelopes in sub-Saharan Africa: a time perspective. In Conservation assessment and management plan .for antelopes draft 11: 177-183. Sausman, K. A. (Comp.). Gland, Apple Valley & Palm Desert: IUCN/SSC/CBSG and The Living Desert. Esns, R. (1992): Conservation of keystone species. In Conservation assessment and management plan for antelopes draft 11: 185. Sausman, K. A. (Comp.). Gland, Apple Valley & Palm Desert: IUCNiSSC CBSG and The Living Desert. FOOSE. T. J. & SEAL, U. S. (1992): C'onservu/ion assessment and management plans and global captive action plans. Gland & Apple Valley: IUCN/SSCCBSG. MACE, G. M. & LANDE, R. (1991): Assessing extinction threats: toward a re-evaluation of IUCN threatened species categories. Conserv. B i d . 5(2):

NOWAK, R. M. & PARADISO, J. L. (1983): Walker's mummal.s of the world 2 (4th edn). Baltimore, London: Johns Hopkins University Press. SAUSMAN, K. A. (1989a): Survey of artiodactyls in captivity. Gland, Apple Valley & Palm Desert: IUCNjSSCjCBSG and The Living Desert. SAUSMAN, K. A. (1989b): Survey of desert antelopes in eapivity. Gland, Apple Valley & Palm Desert: IUCNjSSCCBSG and The Living Desert. SAUSMAN, K. A. (1990): Survey and action plan f o r artiodactyls in captivity. Gland, Apple Valley & Palm Desert: IUCN,'SSC/CBSG and The Living Desert. SAUSMAN, K. A. (1991): Survey und action plan .for artiodactyls in captivity. Gland, Apple Valley & Palm Desert: IUCNISSCCBSG and The Living Desert. SEAL, U. S., SAUSMAN, K. A. & MIKOLAI, J. (Eds) (1990): CBSG aridland antelope workshop report: Sun Antonio, Texas, USA, 13-15 September 1989. Apple Valley, MN: IUCN/SSC/CBSG. WILSON, V. J. (1987): Pan African decade of duikrr research, i 1985-1994 j . Action plan for duiker conservation. Gland & Bulawayo, Zimbabwe: IUCNjSSC Antelope Specialist Group & Chipangali Wildlife Trust.

148-1 57.

Manuscript submitted I3 January 1993