Rare Antelope Research Articles

Behavioral and endocrine correlates of dominance in captive female Jackson's hartebeest (Alcelaphus buselaphus).

For species that form dominance hierarchies, such as group-living ungulates, aggressive interactions can pose a challenge to successful captive management. For example, Jackson's hartebeest (Alcelaphus buselaphus), a rare antelope of east Africa, can be difficult to maintain in captivity because aggression within female dominance hierarchies can lead to injury and death. We quantified behavioral and endocrine correlates of dominance in a captive herd of ten female hartebeest with the goal of understanding how to minimize dangerous interactions. We observed hartebeest for 18 months in a 4-ha enclosure on St. Catherines Island, Georgia. We quantified type of agonistic behavior, initiator and recipient of the behavior, who displaced whom, and age and relative size of participants. We also used fecal steroid analysis to take weekly measurements of corticoids, a hormonal correlate of stress. Hartebeest maintained a stable, linear dominance hierarchy. Only 5.9% of interactions were reversals of established rank. Most dominance interactions were low intensity, but 17.3% of interactions carried a high risk of injury (chase, horn butt, horn clash, horn clash on knees, and head push). High-ranking individuals usually initiated interactions. Most interactions were between animals of similar rank, and animals of intermediate rank participated in the highest number of interactions. The frequency of high-intensity interactions was unrelated to rank. Rank was correlated with age, but not size. There was no relationship between rank and fecal corticoid levels. Dominance interactions in hartebeest are not a function of social instability, and the frequency of dangerous interactions is not a function of rank.

Are relatively rare antelope narrowly selective feeders? A sable antelope and zebra comparison

AbstractAnimals that are relatively rare in local species assemblages are commonly assumed to be narrowly selective in their habitat or dietary requirements, with the latter generally assessed in terms of the range of food types consumed. We investigated whether a narrow dietary range might help explain the restricted distribution and low local densities attained by sable antelope Hippotragus niger compared with other grazing ungulates. Selection by sable antelope for grass species, its relation to species availability and the resulting evenness of the diet were compared with these measures for zebra Equus quagga, which are assumed to be generalist feeders owing to their hindgut fermentation system, under dry season conditions when food was most limiting. Both grazers exhibited a clear distinction between highly favoured and infrequently accepted or rejected grass species in the same region, and both favoured mostly the same common grass species, but sable showed greater acceptance of several less common grass species than did zebra. Distinctions were evident among individual sable herds in favoured grass species, dependent on local availability. Dietary evenness was similar for sable and zebra herds overall, although seasonal trends differed depending on whether animals concentrated their diet more narrowly on a few grass species or broadened it during more extremely dry conditions. Hence, although sable were more narrowly selective for green leaf content than zebra, the dietary acceptance range of these two grazers at grass species level did not differ fundamentally. In particular, sable readily consumed tall grass species rated as having low to moderate forage value. This dietary tolerance enables sable antelope to occupy savannah woodlands associated with relatively infertile soils where the risk of predation is reduced due to the relatively low abundance of other prey. Accordingly, the causes of local rarity may lie in the restricted availability of food in the places to which these species are restricted by other factors.

Variations in Eastern bongo (Tragelaphus eurycerus isaaci) feeding practices in UK zoological collections

The feeding strategy of the Eastern bongo in the wild is unusual, poorly understood, and few captive feeding recommendations are currently available to zoos. To assess the current state of nutritional husbandry of this rare antelope, eight UK zoos were surveyed. A nutritional husbandry questionnaire was completed and bongos at each zoo were visually assessed by body condition scoring (BCS). Representative samples of the forage and browse consumed by bongos at each zoo were analyzed for nutrient composition using standard agricultural techniques. Significant differences in bongo body condition were found, indicating that zoo husbandry practices are sufficiently varied to have identifiable impacts on the physical condition of the animals. The results highlight a disparity in feeding regimes and diet quality, with significant differences found in forage and browse nutrient compositions and in vitro digestibility. Most forage samples were of a low nutritional quality. Browse provision was found to be largely opportunistic and limited in most zoos. The provision of energy-rich produce was also found to be unnecessary in maintaining a bongo herd at an ideal mean BCS. This survey provides baseline data which may be useful in establishing "good practice" standards for Eastern bongo captive nutrition and highlights several areas requiring further research.

A critical assessment of adaptive ecosystem management in a large savanna protected area in South Africa

This paper uses five inter-related topics (the management of rivers, fire regimes, invasive alien species, rare antelope and elephants) to assess 15 years of adaptive management in the Kruger National Park (KNP), South Africa. The importance of adaptive planning (a process for developing achievable objectives, which is adaptive because objectives are revised as understanding grows), has been highlighted by this assessment, and the KNP’s track record of adaptive planning is better than that of adaptive management. Adaptive management has identified important issues with regard to biodiversity conservation, and resulted in a shift in management focus to these issues. Because the conservation outcomes of management shifts will only manifest themselves in the longer term, the relative success of adaptive management should be measured by the degree to which management has been refocused onto priority issues, and by the rate at which new understanding is generated. Some issues previously seen as important (fire, rare antelope), are now regarded as less so, while others remain important and difficult to solve, although there has been some progress (rivers, alien plants and elephants). It has also proved difficult to implement active adaptive management (large-scale, replicated trials using different approaches), because of local variation and logistical problems. Adaptive management will remain the approach of choice because there is some progress, and no known alternative to managing this complex ecosystem. It is simply not an option to return to the easily-understood “implementable” solutions (such as culling, regular prescribed burning, or artificial water provision) that demonstrably did not work.

Stable isotope evidence for nutritional stress, competition, and loss of functional habitat as factors limiting recovery of rare antelope in southern Africa

A major focus in population ecology is understanding factors that limit rare species. We used stable isotope approaches to diet to determine whether remaining rare antelope populations in Kruger National Park (KNP), South Africa experience i) nutritional stress; ii) competition with sympatric bulk grazers; iii) reduced habitat heterogeneity. Rare species consumed near-pure C 4 grass-based diets throughout the seasonal cycle, in contrast to field observations that reported significant levels of C 3 consumption (browse) by these taxa. This finding, coupled with low faecal %N at the height of the dry season, may indicate nutritional stress, but recent isotopic studies of the same species elsewhere in Africa suggest that field observations overestimated levels of browse consumption. We find little evidence for diet niche overlap between rare antelope with bulk grazing species. This partitioning of resources (interpreted mainly as tall- versus short-grass grazing, respectively), is consistent with reported differences in observed diet, and comparative oral morphology. Last, we find less seasonal diet variations amongst bulk grazers feeding in rare antelope habitats compared with other landscapes. We propose that loss of functional heterogeneity, apparently brought about by high densities of artificial waterholes, limits recovery of diet- and habitat-selective rare antelope populations in KNP.

Habitat selection by a rare forest antelope: A multi-scale approach combining field data and imagery from three sensors

It can be difficult to further scientific understanding of rare or endangered species that live in inaccessible habitat using traditional methods, such as probabilistic modeling based on field data collection. Remote sensing (RS) can be an important source of information for the study of these animals. A key advantage of RS is its ability to provide information over an animal's complete range, but models incorporating RS data are limited by RS's ability to detect important habitat features. In this study, we focus on the rare, poorly-understood mountain bongo antelope (Tragelaphus euryceros isaaci) which survives in the wild in isolated pockets of montane forest in Kenya. We hypothesize that mountain bongo habitat is multi-scaled. We analyzed field and RS data (derived from SPOT, ASTER, and MODIS) ranging in scale from 0.02–85.93 ha to test our hypothesis. Important microhabitat features were identified through logistic regression models of vegetation structure data collected in plots (0.04 ha) of bongo presence (n=36) and absence (n=90). Models were selected using an information theoretic approach. We analyzed the correlations between microhabitat (four canopy and four understorey structure measures) and RS variables derived using spectral mixture (SMA) and texture analysis; most ASTER and SPOT variables were significantly related with canopy structure variables (max|r|=0.56), but correlations between understorey structure and all but two RS variables were insignificant. Further logistic regression modeling showed that combining field microhabitat (primarily understorey structure variables) and larger-scaled RS measures (ASTER spectral mixture analysis variables aggregated to 450 m (20.25 ha)) provided superior models of bongo habitat selection than those based on field or RS data only. The results demonstrate that: 1) forest canopy characteristics at scales of ~20 ha and understorey structural conditions at the micro-scale of 0.04 ha were the most important features influencing bongo habitat selection; 2) models for predicting bongo habitat distribution must incorporate both micro- and macro-habitat variables; 3) optical RS data may characterize important micro-scale canopy variables with reasonable accuracy, but are ineffective for detecting understorey features (unless alternative techniques such as forest structural indices can be successfully applied); 4) RS and field data are both essential for understanding bongo habitat selection. The technique employed here for understanding this rare antelope's habitat selection may also be applied in studies of other large herbivores.

Challenges faced in the conservation of rare antelope: a case study on the northern basalt plains of the Kruger National Park

The conservation of rare antelope has long been one of the goals of the Kruger National Park. The roan antelope Hippotragus equinus, and to a lesser extent the tsessebe Damaliscus lunatus, represent low-density species or rare antelope in the park. Specific management approaches representing the older equilibrium approach, have been employed to conserve these antelope. Of these, the supply of artificial water over many decades was the most resource intensive. The sudden, severe drop in the roan antelope population towards the end of the 1980s was unexpected and, retrospectively, attributed to the development of a high density of perennial waterpoints. The postulated mechanism was that the perennial presence of water allowed Burchell’s zebra Equus burchelli to stay permanently in an area that was previously only seasonally accessible. The combined effect of a long, dry climatic cycle, high numbers of zebra and their associated predators was proposed to be the cause of this decline. As part of the new nature evolving or ecosystem resilience approach, twelve artificial waterpoints were closed in the prime roan antelope habitat in 1994 in an attempt to move the zebra out of this area. The zebra numbers declined as the rainfall increased. Closure of waterholes clearly led to redistribution of zebra numbers on the northern plains, zebra tending to avoid areas within several kilometres of closed waterpoints. However, at a larger scale, regional densities appeared similar in areas with and without closed waterpoints. There was an initial drop in the lion numbers in 1995, after which they stabilised. In spite of an improvement in the grass species composition and an increase in biomass the roan antelope population did not increase. The complexity of maintaining a population at the edge of their distribution and the problems associated with the conservation of such populations are discussed in terms of management options and monitoring approaches that may be employed in this process.

Towards an adaptive management approach for the conservation of rare antelope in the Kruger National Park - outcome of a workshop held in May 2000

A precipitous drop in rare antelope numbers specifically roan (<i>Hippotragus equinis</i>) sable (<i>Hippotragus niger</i>) and tsessebe (<i>Damaliscus lunatus</i>) since 1986 has become one of the main concerns of management. The zebra (<i>Equus burchelli</i>) population in the preferred habitats of these species had increased with the development of artificial waterpoints especially in the areas occupied by roan and tsessebe, and these events are hypothesised to be the main cause of the decline. Closure of artificial waterpoints resulted in moving the high-density, water-dependent zebra from the northern basalt plains, the preferred roan habitat. However, the expected responding increase in the rare antelope populations did not materialise. This lack of response over six years necessitated a critical re-evaluation of the management of rare antelope in the Kruger National Park. Subsequently, a workshop was held at Skukuza during May 2000. The options for adaptive management of the declining rare antelope populations, which was discussed at the workshop, is the subject of this manuscript. The participants felt that the removal/closure of artificial waterpoints was the most unintrusive management tool available to move high density grazers from the habitats preferred by rare antelope. Waterpoints to be closed should be carefully evaluated, and time allowed for rare antelope to respond to habitat changes. Boosting populations of roan and tsessebe by supplementing animals was seriously considered, with the proviso that it should be done under favourable circumstances. Small patch fires that could provide green grazing over extended periods were recommended. Predator control was discussed but could not obtain general support as a viable option in the Kruger National Park.

National Park in Ethiopia urged for rare antelope

National Park in Ethiopia urged for rare antelope

British Museum (Natural History): Acquisitions

THE most important recent zoological accession to the Zoological Department of the British Museum (Natural History) is perhaps a collection of mammals and birds made by Messrs. Charles and Edward G. Bird in the Mygybukta region of North East Greenland. The collection is of special interest since it contains examples in breeding plumage and chicks of birds well known in the British Isles in winter, such as the knot, sanderling, turnstone and brent goose. There are also specimens of the ptarmigan in breeding plumage, as well as young birds and small ducklings of the king eider—a rare visitor to Britain. Among the mammals are specimens of the lemming, skulls and skeletons of arctic foxes, and various seals. Another important acquisition to the Department is the mounted head of a chobe situtunga (Limnotragus spekei selousi) presented by Major Henry Abel Smith. This rare antelope is known only from about a dozen specimens and enjoys a distribution to the south of the Zambesi between the Chobe Swamps and Lake Ngami in Bechuanaland. Among the accessions to the Department of Entomology is the very valuable collection of butterflies formed by Major P. P. Graves in the Near East, particularly in Palestine, Asia Minor, Syria, the southern Balkans and Greece. This collection is made up of more than 9,000 specimens, and is particularly rich in material from historic localities which were extensively worked by German and Austrian collectors in the middle of the last century.