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Human-wildlife conflict and habitat loss are threatening carnivore populations in southern Africa, where the bulk of research focuses on large predators. However, scant research exists on medium and small carnivore (mesocarnivore) ecology. We employed hierarchical community modelling to estimate the effect of habitat on species occurrence and the effect of bait on detection probabilities for the carnivore community in the Mashatu Game Reserve, Botswana. We tested sites baited with either impala (Aepyceros melampus) meat (meat sites) or cheesecloth soaked in used cooking fat (fat rag sites) against unbaited sites (control sites). Within each bait classification, we divided our sampling effort between two habitat classifications, riverine and non-riverine sites. Thirteen of 16 carnivore species inhabiting the area (81%), including 10 of 12 species of mesocarnivore (83%), were recorded. Occupancy rates were higher in riverine habitat for several species, in particular African civet (Civettictis civetta), bro...

In eastern and southern Africa, some ranch owners are now keeping cattle overnight in temporary corrals (hereafter referred to as kraals) within rangelands for short durations to improve grass production. However, this has profound effects on the woody plant community. For instance, cattle break woody plant stems and strip them of foliage, initiating resprouting. The resprouts produced have high foliar nitrogen (N) and reduced condensed tannin (CT) concentrations, making them attractive to herbivores. The aim of this study was to determine the key nutrient-quality parameters of resprouts that make previously kraaled sites attractive to impala soon after cattle removal at Debshan Ranch in central Zimbabwe. We determined resprout length, foliar N, phosphorus (P), potassium, CT, fibre and rumen fermentation of three browse species, viz. Grewia monticola Sond., Terminalia sericea Burch. ex DC. and Dichrostachys cinerea (L.) Wight and Arn., and related them to impala use of previously kraaled sites. We used impala dung density to determine the use patterns of previously kraaled sites 2, 4, 12 and 24 weeks after cattle removal and compared them with the surrounding vegetation. Impala use of previously kraaled sites was highest 4 weeks after cattle removal and lowest in the surrounding vegetation. Resprout length increments were 6-fold over a 10-week growth period in all three woody species. Foliar N and P were generally higher, whereas CT was lower, in previously kraaled sites than the surrounding vegetation in all three of the plant browse species. Impala use of previously kraaled sites showed a strong negative relationship with foliar CT. We conclude that kraaling initiates strong resprout responses by woody plants soon after cattle removal, to produce resprouts of high nutrient quality, which attract herbivores such as impala.

This investigation analyses the commercial carcass yields and chemical composition of impala (Aepyceros melampus). The potential of this species for the export market is also discussed. Impala rams (eight) and ewes (eight) cropped commercially in Zimbabwe were found to have a similar dressout proportion (580 g kg), although the males had a heavier live weight (49.4 ± 4.606 kg) than the females (33.5 ± 3.417 kg). Sexual dimorphism was shown, with the males having significantly (p 0.2) were found in the mean chemical proximate composition of the 9-10-11 rib cut for the moisture (724.0±14.00g kg pooled sample), protein (238.3 ± 7.46 g kg pooled sample) and ash (21.2 ± 3.74 g kg pooled sample) contents. The females had a statistically higher (p = 0.0197) mean total lipid content (33.9 ± 1.705g kg) than the males (24.5 ± 3.171 g kg). This investigation occurred at the end of the impala rut season, a period when the rams not only consume less feed but also expend more energy owing to strenuous activities in fighting for and maintaining a harem. (C) 2000 Society of Chemical Industry.

The study was done in Lake Mburo area, Uganda, consisting of Lake Mburo National Park and surrounding ranches. The study involved monitoring changes of output of helminth eggs per gram (e.p.g.) by impala for 12 months. Fresh faecal samples, 178 in total, were collected from the rangeland and subjected to floatation and culture tests. There was a peak faecal e.p.g. output from March to April and from October to November. This period coincided with time of high rainfall and calving peak of impala. There was no faecal e.p.g. observed during the dry spell from June to July. Resume Cette etude fut menee dans la region du Lac Mburo en Uganda, comprenant le Lake Mburo National Park et les ranchs avoisinants. Elle a implique la surveillance continue des variations de l’expulsion d’oeufs d’helminthes par gramme (e.p.g.) par les impalas durant 12 mois. Au total, 178 echantillons fecaux frais furent collectes dans la zone d’etude et soumis a des tests de flottation et de culture. On a constate un pic d’expulsion d’e.p.g. fecaux de mars a avril et d’octobre a novembre. Cette periode coincidait a l’epoque des fortes pluies et du pic des mises bas de l’impala. On n’a observe aucune e.p.g. fecale durant la periode seche de juin a juillet.

The small population of wild dog Lycaon pictus (n= 3 to 30) in Hluhluwe-Umfolozi Park (HUP) has declined since 1992. The survival of dogs in HUP is dependent on the reintroduction of more dogs; however, wild dog reintroduction programmes are fraught with problems and many have failed. In this paper the diet and capture success of the wild dog pack in the Hluhluwe Section, and the influence of dietary considerations on the success of the future reintroduction of wild dogs in this reserve, are investigated. Diet choice was determined from scat analysis, personal observation and field staff records. Eight ungulate prey species were identified from scat analysis: nyala Tragelaphus angasi and impala Aepyceros melampus were the most abundant ungulate species in HUP and accounted for 77% of the diet. On the whole, wild dogs included prey types in the diet consistent with a rate-maximizing foraging approach, although some prey were clearly taken opportunistically. The dogs preyed mostly on small- (> 25 kg) to medium-sized (40–90 kg) prey, while the young of large (< 90 kg) prey species or scavenged carcasses supplemented the diet during the dry season. Adult nyala were taken more frequently than other age classes, but wild dog preyed on juvenile impala more than expected. Female prey were taken more frequently than males but selection did not differ from prey population sex ratios. Prey capture success was similar to that of previous studies from both open and densely wooded habitats and the wild dogs successfully caught 48% of all prey species pursued. Results suggest that wild dogs are quite capable of adapting both their diet choice and foraging technique to the dense vegetation in HUP. We conclude that prey type, prey availability and habitat constraints on prey capture success, will not affect the reintroduction of more wild dogs into HUP.

Impala Aepyceros melampus and wildebeest Connochaetes taurinus vigilance behaviour was concurrently monitored in two adjacent sites where re-introduction of large felids at one site gave rise to increased predation pressure. In the high predation site, rate of looking and proportion of time spent looking by both species was significantly greater than in the low predation site. Vigilance behaviour also showed an increase over time following feIid re-introduction: there was no increase where re-introduced feIids were absent. The relationship between vigilance and herd size, position in herd and presence of juveniles was compared for high and low predation conditions. Herd size and vigilance behaviour showed a negative correlation for both species regardless of predation conditions. Mothers with juveniles were always the most vigilant members of the herd and central animals were always the least watchful in both predation conditions. The interplay between vigilance behaviour and predation pressure, herd size, position in herd and presence of juveniles is discussed. It is suggested that predation pressure is the principal influence on vigilance behaviour in ungulates and even very low risk of predation appears to contribute to vigilance. Impalas and wildebeest spared the risk of predation devoted very little time to vigilance, suggesting it played a minor role in intraspecific interactions and finding food.

Restriction-endonuclease site maps of mitochondrial DNA were constructed for members of the family Bovidae emphasizing species in the Alcelaphinae, Bovinae, and Aepycerotinae. Cladograms weakly supported sister status of the impala, Aepyceros melampus , relative to the Alcelaphinae, and monophyletic status of the Bovini and Tragelaphini. Four members of the Tragelaphini remained an unresolved quadrichotomy, which would be consistent with the inclusion of the eland, Taurotragus oryx , within Tragelaphus . The restriction data are consistent with a radiation for the Tragelaphini at the end of the Miocene.

Oral grooming is highly eVective in removing ectoparasites in ungulates and other species. The programmed grooming model postulates that preventive oral grooming bouts are periodically activated by an internal timing mechanism (clock), with grooming rates modulated according to fitness costs and benefits. The 'body size principle' of the programmed grooming model, developed from interspecific comparisons, predicts that animals or species of smaller size, because they cannot tolerate as great a density of engorging ticks per unit of body surface area, will groom at a higher rate than those of larger size. Accordingly, within a species, young animals should groom at a higher rate than adults. The 'tick challenge principle' states that the rate of programmed grooming will be regulated as a function of tick bites such that animals will groom more frequently when tick exposure in the habitat is greater. These predictions were tested by comparing self-grooming rates of impala, Aepyceros melampus, lambs and their mothers at three study sites ranging from tick-dense to tick-sparse or tick-free. As predicted, newborn lambs from 1-5 weeks postpartum self-oral groomed at about three times the rate of their mothers, and young lambs 6-12-weeks-old self-oral groomed at least twice as frequently as maternal conspecifics; self-oral grooming rate of older (7-8-month-old) lambs was no diVerent from that of adults. Presumably, the timing mechanism slowly changes its rate as impala mature, reflecting increased costs of self-oral grooming (attrition of the dental elements used in oral grooming and distraction from vigilance over predators) relative to declining body surface:mass ratio. Both lambs and their mothers consistently self-groomed at a higher rate at the tick-dense study site compared with the tick-sparse or tick-free sites. The results are in line with the concept that an intrinsic grooming clock is responsible for regulating body-size and tick-challenge specific grooming rates that enable impala to survive and thrive in a tick-infested environment. ? 1997 The Association for the Study of Animal Behaviour

A retrospective serosurvey was carried out between 2009 and 2012 to detect antibodies to Brucella spp. in free-ranging African wildlife ungulates from five selected game parks in Zimbabwe. Samples were drawn from wildlife-livestock interface and non-interface areas in Zimbabwe. A total of 270 serum samples from four different species, namely African buffalo (Syncerus caffer) (n=106), impala (Aepyceros melampus) (n = 72), black rhinoceros (Diceros bicornis) (n= 45) and white rhinoceros (Ceratotherium simum) (n = 47), were tested. The percentage of positive samples was 17.0% in buffalo (18/106; 95% CI: 9.72% – 24.1%) and 1.4% in impala (1/72; 95% CI: 0% – 4.2%). No antibodies to Brucella spp. were detected in the two rhinoceros species. The difference in the percentage of seropositive cases between buffalo and impala was significant (p< 0.05). Seropositivity to Brucella spp. was higher (19.1%) in adult buffalo compared with juveniles and sub-adults younger than six years (5.9%). Further, seropositivity was marginally higher (20.4%) in animals from wildlife-livestock interface areas than in those from non-interface areas (13.45%; OR = 1.45) although the difference was not statistically significant. The study showed that brucellosis could be more widespread in buffalo and may circulate in this species independently in the absence of contact with cattle, whilst rhinoceros may be considered less susceptible to brucellosis. The role of the wildlife-livestock interface in the epidemiology of brucellosis in wildlife and livestock is probably overstated but needs to be explored further.

Molecular characterization of Cryptosporidium spp. was done on isolates from African elephant (Loxodonta africana), African buffalo (Syncerus caffer), impala (Aepyceros melampus) and native domestic calves collected during May and June 2008 at the wildlife/livestock interface of the Kruger National Park (KNP), South Africa. A polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) analysis of the 18S rRNA gene was used in feces from 51 calves (3-12 months of age), 71 buffalo, 71 impala and 72 elephant, and sequencing of the 18S rRNA gene was done on PCR-RFLP-positive wildlife samples. Cryptosporidium spp. were detected in 8% (4/51) of the calves and identified as C. andersoni (2/4) and C. bovis (2/4). Four of the 214 wildlife samples were positive for Cryptosporidium with a prevalence of 2.8% each in impala and buffalo. Cryptosporidium ubiquitum was detected in two impala and one buffalo, and C. bovis in one buffalo. A concurrent questionnaire conducted among 120 farmers in the study area investigated contacts between wildlife species and livestock. Buffalo and impala had the highest probability of contact with cattle outside the KNP. Despite the fairly low prevalence found in wildlife and cattle, the circulation of zoonotic Cryptosporidium spp., such as C. ubiquitum, should be investigated further, particularly in areas of high HIV infection prevalence. Further studies should target younger animals in which the prevalence is likely to be higher.

International audience; Background: Partial migration, where one portion of a population conducts seasonal migrations while the other remains on a single range, is common in wild ungulate populations. However the relative costs and benefits associated with the distinct strategies adopted by coexisting migrant and resident individuals have rarely been investigated. Here we compare the body condition of migrants and residents in a partially migratory population of impalas (Aepyceros melampus) in Zimbabwe. The study was conducted during two consecutive years with highly contrasted population densities (16.4 and 8.6 indiv/km(2)) due to harvesting. Results: We first identify a population substructure with a north-south sub-division in two spatial units related to distinct soils and vegetation cover. Impalas in the north range had a consistently higher diet quality and body condition than those in the south range. At the beginning of the dry season about one third of the individuals migrated from the lower (i.e. south) to the higher (i.e. north) diet quality range. This partial migration pattern was consistent between the consecutive years, and most individuals showed constancy to their moving strategy (migrant or resident). In both years, these migrants had a significantly higher body condition at the end of the dry season than the south residents that remained year-round in the lower diet quality range. Diet quality and body condition of impalas were higher in the year of lower density; however we did not detect any evidence for density-dependence in migration propensity, at the individual or population levels, nor in the benefit associated with migration. Conclusions: Our findings provide rare evidence for a significant relationship between body condition and seasonal migration strategy in wild ungulates in relation to a difference in the quality of resources acquired between distinct seasonal ranges. This study also constitutes rare evidence of partial migration in a tropical ungulate population.

Activity pattern plasticity in ungulates serves as an evolutionary adaptation to optimize fitness in inconsistent environments. Given that time is a limited and valuable resource for foraging wildlife species, provisioning and attraction may affect the activity pattern plasticity and reduce complexities of time partitioning for different activities by impala in closed environments. We assessed activity budgets of free-ranging impala social groups in a closed environment. Social group type had an influence on the activity budgets of impala except for foraging and moving activity states. Both the harem and bachelor groups spent more than 30% of their daily time foraging. Bachelor groups spent more time exhibiting vigilance tendencies than the harem groups. Season influenced the activity budgets of social groups other than vigilance and foraging activity states. Foraging time was highly correlated with vigilance, resting, and grooming. We concluded that provisioning and attraction may have reduced the influence of seasonality on the proportion of time spent on different activity states by impala social groups. There is a need to establish long-term socioecological, physiological, and reproductive consequences of provisioning and habituation on impala under closed environments.

The livers of impala (Aepyceros melampus) collected in the Mlawula-Mbuluzi-Simunye Nature Reserve and Protected Area complex in northeastern Swaziland from October 1985 to September 1986 were infected with three species of helminths: a nematode (Cooperioides hepaticae), a cestode (Stilesia hepatica), and a trematode (Fasciola gigantica). Cooperioides hepaticae caused a severe cholangitis. Lambs were infected at 1.5 to 2 mo of age, and the prevalence increased to 100% by 5 mo of age. The prevalence was 82% in yearlings and 44% in adults, with the highest prevalence and intensity of infection at the end of the dry season. Stilesia hepatica was found primarily in adults. Heavy infections caused a thickening and distension of the main bile ducts, but no changes were evident in the liver parenchyma. Fasciola gigantica, found only in one adult male, caused a thickening and distension of main bile duct. There was no apparent association between the helminth infections and body condition.

Quantitative data on host tick burdens are fundamental for the initiation of control strategies and effective management of wildlife populations, but the methods of live sampling employed for domestic animals are unsuitable for sampling wild animals. Despite advances in the use of destructive methods (the scrub and digestion techniques) to obtain measures of the total tick burden on wildlife, these methods are too involved for many field workers, who often need only measures of relative tick burden. Recently, patch sampling methods have been introduced whereby only certain predilection sites are sampled, the presumption being that the number of ticks collected gives an indication of the relative degree of infestation. We examined the validity of patch sampling as a measure of relative tick burden by comparing adult ticks collected from the ears, head, neck, foreleg and perianal region of impala (Aepyceros melampus) with total tick burdens of the same animals derived from the digestion technique. Adult ticks from patch sampling were positively and significantly correlated with total adults and total ticks (larvae, nymphs, and adults) on impala, with ticks patch sampled from the neck showing the highest correlation with the total tick burden. Comparison of relative tick loads from patch sampling with absolute tick loads from digestion for three classes of impala (females, bachelor males and territorial males) gave qualitatively similar results. We conclude that, when measures of relative tick load are sufficient and destructive sampling is not feasible, patch sampling can provide reliable information on relative tick burdens that are positively correlated with the total tick burden.

Grooming is among the most commonly performed parasite defence behaviour patterns and is eVective in removing ticks. Because both tick infestation and grooming activity have a cost, natural selection should favour individuals that match the current level of tick threat with an appropriate level of tick-defence grooming eVort. To test this notion, the relationship between seasonal tick challenge and grooming rate by wild, free-ranging impala, Aepyceros melampus, was investigated in Zimbabwe. Adult ticks in the vegetation showed a dramatic decrease from the warm/wet season to the hot/dry season, declining from 2·4 ticks per drag sample and 58 ticks per removal plot to virtually nil. This decline was mirrored by an associated decline in grooming rate by all impala in which self-oral and scratch grooming bouts per h decreased 30-45%. Allogrooming encounters per h (corrected for lying-down time) and total allogrooming delivered, as measured by bouts or episodes delivered per h, decreased for males but did not change for females. Overall percentage of time spent in all forms of grooming declined 37-57%. Multiple regression analysis revealed that, with the seasonal eVects of temperature and rainfall held constant, self-grooming rates were significantly and positively correlated with adult tick challenge, indicating that impala adjusted self grooming to seasonalfluctuations in adult tick threat. Allogrooming delivered was influenced by nymphal tick challenge; because the larvae and nymphs of the most abundant tick species favour the ear and neck region (where allogrooming is concentrated), allogroom- ing appears to function to remove immature ticks from body regions inaccessible to self-oral grooming. These results are what would be expected if grooming serves to remove ticks before they can attach and engorge, and supports the view that grooming is an evolved response to the threat of excessive tick burden in the impala's natural environment. ? 1995 The Association for the Study of Animal Behaviour

Five species of ixodid ticks, Amhlyomma hebraeum, Boophilus decoloratus, Rhipicephalus appendiculatus, R. evertsi evertsi and R. muehlensi, were commonly collected from impala (Aepyceros melampus) ...

The previously unknown life-cycles of Haemonchus bedfordi, Impalala tuberculata and Longistrongylus sabie parasitic in impala, are recorded. Observations on the morphology of the developmental stag...

Ixodid ticks and other ectoparasites were collected from impala ( Aepyceros melampus ). blue wildebeest ( Connochaetes taurinus ), kudu ( Tragelaphus strepsiceros ), common duiker ( Sylvicapra grimmia ) and warthog ( Phacochoerus aethiopicus ) in the Mlawula-Mbuluzi-Simunye Nature Reserve and Protected Area complex and Hlane Wildlife Sanctuary in the Swaziland lowveld, and from blue wildebeest and warthog in Malolotja Nature Reserve in the highveld from October 1985 to August 1986. The most commonly collected ticks were Amblyosomma hebraeum, Boophilus decoloratus, Rhipicephalus appendiculatus, R evertsi evertsi, R maculatus, R muehlensi and R simus . The diversity and intensity of infestation were greater in the lowveld, where the ectoparasite community was similar to that reported from these host species in the eastern Transvaal lowveld and Kwazulu/Natal. A hebraeum was collected throughout the year, but the largest samples were in October and November when the animals were in poor condition. The seasonal occurrence of R. appendiculatus adults on impala was later than that reported for other host species, possibly owing to seasonal changes in habitat use. Seasonal changes in habitat use and temperature effects on pre-oviposition and development of the eggs may have caused the seasonal patterns in the occurrence of B. decoloratus .

Ex-situconservancies are expanding alternatives to livestock production in Zambia albeit the lack of information on circulating infectious parasites from wildlife. Therefore, 12 wildlife species were examined on a game ranch were all species were found to be infected byRhipecephalusspp. Haemoparasite infections were estimated at 7.37% (n=95) withBabesiaspp. detected in bushbuck (Tragelaphus scriptus);Anaplasma marginalein impala (Aepyceros melampus) and puku (Kobus vardonii) for the first time in Zambia. The majority of worm species isolated from bovids were not detected in equids and,vice versa. Our findings intimate ecological and behavioural patterns of some animals as deterministic to exposure. Kafue lechwe (Kobus leche kafuensis) had the widest range of worm species with more infected organs than other animals suggesting their semi aquatic nature contributory to prolonged worm exposure compared to other animals. On the other hand, Kafue lechwe had the least tick infections attributable more to shorter attachment periods as they spend prolonged periods submerged in water. Our findings indicate the vital role that wildlife plays in the epidemiology of parasitic diseases. To reduce the infection burden, control measures should be focused on reducing transmission to highly susceptible animal species as described herein.

Climate change, habitat loss and fragmentation individually or synergistically force species to live in a sub-optimal condition in terms of climate and resource posing threat to fitness and survival of the species. Hence, a very pressing issue for biodiversity conservation at present is to understand if species are able to keep pace with these rapidly changing environment conditions. To persist with these changes, phenotypic plasticity of behaviour and physiology may be the most likely response for long-lived endothermic species because of their longer generation times. Therefore, the central aim of this thesis is to investigate intra- and intervariability of behavioural and physiological adaptation of range of African antelopes along spatio-temporal scales in their natural habitats. With the aim to understand the behavioural plasticity of African antelopes to the climatic stress, in Chapter 2, I investigated effect of heat stress on diurnal activity pattern of three species of antelopes of different body size and feeding types namely, eland Taurotragus oryx (≈ 420 kg; mixed feeders), blue wildebeest Connochaetes taurinus (≈180 kg; grazer) and impala Aepycerus melampus (≈ 50 kg; mixed feeder) across season and extreme climatic condition as indicated by the 10 hottest days. During summer when the heat stress was its highest, the heat stress negatively influenced diurnal activity of all the three species. However, they shifted the timing of their activity more to the early morning (eland) or late in the evening, or both (wildebeest and impala) to avoid heat stress and maximize intake of food in a season when forage is abundant. During the spring and the 10 hottest days over the entire study period, only the diurnal activity of the larger antelopes (eland and wildebeest) was negatively influenced by the heat stress whereas the smaller impala was unaffected. Therefore, these large African antelopes apparently suffer from heat stress during spring and the extreme hottest days due to their limited capacity to dissipate heat. In chapter 3, to understand possible behavioural adaptation of the largest African antelope eland against the thermal stress, I investigated the daily and seasonal selection of microhabitats based on altitude and microclimate at the southern limits of its distributional range. Eland actively selected lower altitudes with warm microclimates during the winter and the five coldest days when the ambient conditions were below its thermal neutral zone. In contrast, eland did not select higher altitudes or cooler climate when it was warm in the summer. However, selection of cooler microhabitats was only evident in the three extremely hottest days when the heat stress was close to the upper end of its thermal neutral zone. Hence, the eland was able to use diverse topography as a thermal refuge to buffer the adverse effect of both cold and very hot condition. In the fourth chapter, to study behavioural response of African antelopes to variation in food resources which is predicted to exacerbate due to climate change and habitat loss and fragmentation, I investigated adaptation of home range sizes of eland, impala (both mixed feeders) and wildebeest (a grazer) over time (seasons) and between two climatically contrasting areas in South Africa, taking Mapungubwe National Park as the core area and Asante Sana Game Reserve as the edge area. This comparative study not only showed the home range size of wildebeest in Mapungubwe was larger during the resource-poor dry season compared to the resource-rich wet season but their home range size in the core area was also a four to seven times larger in the dry season than those in the edge area. In contrast, the home range size of impala was 3-14 times larger in the edge area than those in the core area. Surprisingly, the home range size of eland neither differs across any season within study areas nor between Asante Sana and Mapungubwe, while their average year-round home range size in core area was larger than that in edge area. These results suggest that the home range size of these African antelope is most likely a response to resource quality and availability specific to the local habitat. With an attempt to investigate physiological plasticity of African antelopes over a spatiotemporal context, in Chapter 5, I compared intraspecific variation of body temperature, as measured by amplitude, of the eland, blue wildebeest and impala in the two climatically contrasting areas: one with a less seasonal pattern and a mild winter (Mapungubwe National Park) and the other with a more seasonal pattern and a long and cold winter (Asante Sana Game Reserve). The 24-hour amplitude of body temperature of both mixed feeder (eland and impala) did not differ between the study sites, regardless of season. In contrast, the grazer (wildebeest) at a less seasonal site exhibited not only a higher variability in the 24-hour amplitude of body temperature (Tb)(~4ºC) but also a lower daily minimum body temperature by ~2 ºC compare to the normothermic level during the dry season than the wildebeest at a seasonal site. Further, the variation in Tb amplitude were influenced both by temperature (positive effect) and rainfall (negative effect), a proxy for food availability only among the wildebeest from less seasonal site. This suggest that these physiological response of higher variability of Tb amplitude and reduced minimum Tb among the wildebeest in Mapungubwe is a response to nutritional stress rather than a response to cold climate. These behavioural (home range) and physiological (body temperature) response of African antelopes to stressful conditions are specific for species and habitats. The smallest impala, which is a mixed feeder, maintained homeothermy even though they were exposed to stressful habitats by selecting the most productive habitat, i.e., riparian habitat in Mapungubwe. In Asante Sana, impala maintained homeothermic status by extending their dry season home range size when their principle food Acacia Karoo was not available. The largest antelope (eland) maintained homeostasis by ranging over large areas to track heterogeneously distributed resources, which is only possible due to their large size and ability to cope with lower quality food. Eland in Mapungubwe had larger home range sizes compared to Asante Sana which was most probably due to the poor quality of the habitat in Mapungubwe. Interestingly, the wildebeest in Mapungubwe did not maintain homeothermy particularly in dry season. Not only their amplitude of Tb was much larger (~4ºC) and Minimum Tb lowered by 2 ºC compared to normothermic level, they also extended their home range size four to seven folds compared to the wildebeest in Asante Sana. This failure to maintain homeothermy and extension of home range size was due to nutritional stress and therefore these antelopes are living in a physiologically stressful environment. With the predicted increase in the frequency and intensity of drought periods in southern Africa due to climate change, wildebeest, and other grazers, will likely experience greater nutritional stress in the future. To conclude, this thesis shows importance of studying behavioural and physiological traits among a range of species along temporal and spatial scales in their natural habitats to understand the adaptive capacity, therefore sensitivity of animal species. Apparently, homeothermic mammals cannot cope well with heat stress, which negatively influence the larger ones more than the smaller ones. However, mammals can overcome these stresses by shifting time of their activity to cooler parts of the day or by selecting optimal microhabitats that minimize absorption of heat at high temperatures or that maximize the absorption of heat at low temperatures. The behavioural (larger home range size) and physiological (reduced body temperature) response of wildebeest, a grazer to dry season but not that of the mixed feeder emphasizes that grazers will become more nutritionally stressed than mixed feeders at times of low rainfall. With the predicted increase in low rainfall events in many parts of the world and changes in vegetation structure in savannas due to climate change, browsers and mixed feeders will be likely to benefit more in future than the ruminant grazers.

Summary A study of habitat selection by oribi (Ourebia ourebi, Zimmermann 1783), a small antelope in northern Serengeti National Park, Tanzania, addressed two questions: (1) what were the most preferred habitat features? and (2) did oribi associate with or avoid other ungulates? These questions were pertinent to three hypotheses on the function of habitat selection in antelopes: (i) habitats are chosen to minimize the cost of obtaining resources, (ii) habitat selection results from niche partitioning due to interspecific competition, or (iii) habitat selection functions to avoid predation by using escape terrain and by associating with other species for protection. Results from transects designed to examine preferences for open grassland, Acacia woodlands, Combretum-Terminalia woodland, forests, thickets and rocky habitat types suggested that oribi preferred habitats with rocky outcrops and Combretum-Terminalia woodland. These habitats supported preferred food plant species consistent with hypothesis (i). However, oribi occurred close to rocks in the dry season, and in areas with long grass during the wet season, both of which are used for cover against predators. The significant association of oribi with larger resident ungulates [impala (Aepyceros melampus) and kongoni (Alcelaphus buselaphus)] also suggested that oribi were avoiding predators, consistent with hypothesis (iii). Oribi avoided wildebeest, possibly because of interference, but were randomly associated with topi, zebra and Thomson's gazelle. Preference for plateaux or gentle slopes and green flush agree with studies elsewhere. Major contrasts were shown in the avoidance of open grasslands and Themeda triandra which are reported to be favoured by most oribi populations in South Africa. Resume Une etude de la selection de ľhabitat par ľoribi, Qurebia ourebi, Zimmermann 1783, une petite antilope du nord du Pare National du Serengeti, en Tanzanie, cherchait a repondre a deux questions: (1) Quels sont les elements preferes de ľhabitat? et (2) Est-ce que ľoribi s'associe ou evite les autres ongules? Ces questions se rapportaient a trois hypotheses sur la fonction de la selection de ľhabitat par ľoribi: (i) Ľanimal choisit ľhabitat pour reduire le cout de ľobtention de nourriture. (ii) La selection de ľhabitat resulte du partage des niches, suite aux competitions interspecifiques. (iii) La selection de ľhabitat sert aeviter les predateurs grâce a ľexistence de terrains de secours ou aľassociation avec ?autres especes dont ils obtiennent la protection. Des circuits furent choisis pour examiner les preferences entre les herbages ouverts, les zones boisees ?Acacia de Combretum-Terminalia, les forets, les buissons ou les endroits rocheux. Les resultats suggerent que ľoribi prefere les habitats avec des surplombs rocheux et ceux peuplees de Combretum-Terminalia. Dans ces habitats poussent les especes vegetales preferees, ce qui repond aľhypothese (i). Cependant, on rencontre des oribis pres des rochers en saison seche et dans les zones couvertes ?herbes hautes en saison des pluies, les deux milieux servant de protection contre les predateurs. Ľassociation significative des oribis aves des ongules plus grands comme ľimpala, Aepyceros melampus, ou le bubale, Alcelaphus buselaphus, suggere aussi que les oribis evitent les predateurs, ce qui repond aľhypothese (iii). Les oribis evitent les gnous, peut-etre en raison ?interferences, mais sont parfois associes aux topis, aux zebres et aux gazelles de Thomson. La preference pour les plateaux, les pentes douces et les ilots de verdure concorde avec ?autres recherches. Les plus grandes differences concernent le fait qu'ils evitent les pâturages ouverts et Themeda traindra qui sont recherches, parait-ill, par la plupart des populations ?oribis en Afrique du Sud.

Faecal samples (n = 1947) from captive wild impala (Aepyceros melampus melampus) were examined over a period of 14 months to determine quantitative seasonal helminth egg excretion patterns and qualitative protozoan oocyst excretion patterns. Geometric mean monthly faecal egg counts (FECs) ranged from 20 to 575 and coprocultures revealed three parasite genera, namely Trichostrongylus, Haemonchus and Strongyloides. Larvae of the Trichostrongylus spp. were most predominant from faecal cultures. No trematode eggs or lungworms were detected and eggs of the cestode Monezia were only seen in two samples during the entire study period. The nematode FECs showed a marked seasonal variation, being higher during the rainy season, moderate during the cool dry season and low during the hot dry season. The rainy season had significantly higher FECs than the dry season (P P P>0.05), but were significantly higher in pelleted faeces in the rainy season than the dry season (P P Strongyloides eggs and coccidia oocysts were only seen during the rainy season. This represents the first documentation of seasonal parasitic infestation in captive wild antelopes in Zambia. Treatment and control strategies for helminths in these captive wild impala are also suggested based on the findings from this study.

Veterinary cordon fences are used in Southern Africa to separate wildlife from domestic animals in order to prevent transmission of infectious diseases. Such fences are a control method recognized by the World Organization for Animal Health (OIE) for establishing disease-free zones in beef exporting countries. However, few studies have evaluated the ecological impact of these physical barriers or their effectiveness at a multispecies level. We examined the permeability of one such barrier, along 357 km of the western and southern boundary of the Kruger National Park (KNP) during 2007. Information was gathered using a semi-structured questionnaire implemented among 32 teams of fence maintenance workers. Data were analyzed to identify (a) the main causes of fence damage, (b) the seasonality, location and duration of fence repairs, (c) high permeability areas for elephant (Loxodonta africana), kudu (Tragelaphus strepsiceros), impala (Aepyceros melampus), buffalo (Syncerus caffer) and warthog (Phacochoerus africanus), and (d) the influence of fence electrification, rivers and elephant damage on the frequency of observation of wildlife species outside the KNP estimated during the year. Human and elephant damage were the most common reasons for fence repairs. Elephant and buffalo were the most and least common large mammal species reported observed outside the KNP (1076 and 162 reports/year), respectively. Cattle incursions into the KNP were also reported in 44% of the fence sections. Electrification of the fence was an important factor explaining differences in estimated wildlife species observations outside the KNP during the year. Correlations between estimations of observed species suggested that fence gaps created by elephants might be used by the other wildlife species. Estimated annual counts of kudu, impala and buffalo, but not warthog, were found to correlate with elephant observations. Negative binomial regression models were developed to explore the relationships between observed estimations of different wildlife species outside the KNP the fence, electrification of fence sections and the presence of watercourses, suggesting that kudu, impala and buffalo could use elephant induced fence damage to leave the KNP. The questionnaire was able to evaluate fence integrity and identify sections where integrity was sub-optimal for separating wildlife from domestic livestock species. If combined with more quantitative methods and applied on a routine basis, it could provide an efficient and cost-effective method for monitoring the effectiveness of physical barriers to contain wildlife within protected areas such as is the case with veterinary cordon fences in Southern Africa.

SummaryBetween 1989 and 1992, 7970 wild ungulates, comprising 14 different species, were tested for antibodies to types SAT 1, SAT 2 and SAT 3 foot-and-mouth disease (FMD) virus. Of these 1·2% were found to be positive and these included impala (Aepyceros melampus), eland (Taurotragus oryx), waterbuck (Kobus ellipsiprymnus) and sable (Hippotragus niger). All the positive animals were either from the wildlife areas where buffalo (Syncerus caffer) occur or from ranches where clinical FMD had occurred in cattle. The role of these animal species in the current epidemiology of FMD in Zimbabwe is discussed.

Casual observations have revealed that the anterior dentition of impala and other antelope is loosely embedded, with the tips of the teeth movable over a distance of 1middot;5 to 2mm. The comb-like anterior dentition of impala Aepyceros melampus is utilized extensively for grooming purposes, and it was hypothesized that the looseness of the teeth might be related to the grooming function. A sample of 12 impala mandibles was obtained from Pilanesberg National Park. Boputhatswana. Six of the incisor canine (IC) complexes were examined macroscopically, radiographically and histologically, while the remaining six were used to determine the alveolar depth relative to total root length, The findings were: (1) wide periodontal ligament spaces, most prominent in the apical region; (2) a loose, highly vascular periodontal ligament; (3) well-developed trans-septal periodontal ligament fibres; and (4) relatively shallow alveoli, with only approximately two-thirds of the roots included within the alveoli. In no case could looseness be ascribed to pathological changes in the periodontal ligament, cementum or alveolar bone. These features suggest that the looseness of the teeth is associated with a see-saw action of the teeth about a fulcrum below the alveolar bone crest. with the maintenance of the closed resting position of the teeth being facilitated by the well-developed trans-septal fibres. It is suggested that the minimal interdental space maintained by this arrangement during grooming assists in the efficient removal of parasites from the pelage by impala.

Palaeontology typically relies on fossil studies, in particular morphological differences, to reconstruct and interpret patterns of vertebrate evolution. However, genetic studies of population histories of extant species provide data about past population events (e.g. local extinctions, recolonisations) which are equally relevant to palaeontological questions. This study used morphological traits to evaluate a hypothesis based on genetic evidence that southern African impala (Aepyceros melampus) are the founder population for all other living African impala populations, after an eastern African extirpation event dating to around 200 000 years ago. Measurements of three horn metrics and the presence or absence of a particular dental trait were compared across four regional impala samples. Eastern African impala possess a unique combination of larger horns and a significantly higher occurrence of entostyles when compared to other impala populations. These traits are likely to have characterised a small group of founding impala which recolonised this region. This pattern appears consistent with the genetic evidence that a subset of the southern African impala gave rise to the eastern African populations. Other species with complex population histories, such as wildebeest, eland, topi and hartebeest may also therefore be expected to express variation in certain morphological traits in the fossil record because of similar patterns of recolonisations. The process of local extinction and subsequent repopulation over shorter timescales (102 – 103 years) may pass unnoticed in the fossil record, and lineages may appear uninterrupted. Instead, greater morphological variation within a species may be observed, which may be misinterpreted as reflecting a speciation event, or ecophenotypic variation. Combining data from genetic studies and palaeontology may provide further clues as to how faunal dispersals within Africa shaped the morphological variation in the fossil record, and how to best interpret such differences.

Respiratory depression is a common side effect when opioids are used to immobilize wildlife. Serotonergic ligands have the potential to reverse opioid-induced respiratory depression. We examined whether any of three serotonergic ligands could reverse this depression in etorphine-immobilized (0.07 mg/kg) impala (Aepyceros melampus). The study took place in September-December 2007. Impala received intravenous injections of metoclopramide (10 mg/kg, n=6), buspirone (0.05 mg/kg, n=8), pimozide (1 mg/kg, n=8), doxapram (1 mg/kg, n=6), and control solutions on separate occasions. During the immobilization, partial pressures of oxygen (PaO(2), mmHg) and carbon dioxide (PaCO(2), mmHg), respiratory rate (breaths/min), ventilation (l/min), peripheral O(2) saturation (%), tidal volume (l), and respiratory exchange ratio were measured before and after injection of the experimental drugs. Etorphine immobilization caused respiratory depression and hypoxia (mean+/-SD, PaCO(2)=51+/-2 mmHg, PaO(2)=40+/-3 mmHg). Metoclopramide and buspirone, but not pimozide, attenuated the hypoxic effects of etorphine; 3 min after injection, metoclopramide increased the PaO(2) by 7.5+/-6.3 mmHg and buspirone by 6+/-6.6 mmHg (F=3.9, P=0.02). These effects were similar to those of doxapram (8+/-7 mmHg, F=3.9; P0.05). Neither metoclopramide nor buspirone significantly increased ventilation, but they increased PaO(2) by significantly improving the alveolar-arterial oxygen partial pressure gradient (A-a gradient, F=1.4, P0.05), indicating improved oxygen diffusion. Metoclopramide and buspirone transiently improved blood oxygenation of opioid-immobilized impala, probably by improving ventilation-perfusion ratios, without reversing catatonic immobilization.

Adult female and male impala engage in a type of allogrooming in which partners alternately deliver bouts of oral grooming to the head and neck. These grooming encounters comprise typically six to 12 tit-for-tat-like exchanges of bouts and are highly reciprocal among adult females, adult bachelor males and subadult males. Although allogrooming among females could be between related individuals, that occurring among adult males would appear to be between unrelated individuals. Unlike allogrooming reported for some primate species and other ungulates, the dominant impala received no more grooming than the subordinate. It is proposed that one function of impala allogrooming is to reduce the ectoparasite load on body areas an animal cannot reach with its own mouth. The impala reciprocal allogrooming system is unique among free-ranging antelope and other ungulates and may be a candidate for the tit-fortat strategy of evolved cooperation.

Grooming in ungulates has been shown to be very effective in removing ectoparasites. Ectoparasites, especially ticks, may be costly to an animal's resources in terms of blood removed and depression of appetite. There are two opposing models that address the parasite-control of function of grooming: (1) animals may groom in response to stimulation from parasite bites, whereupon those with the most parasites should groom the most; or (2) animals may groom prophylactically, removing parasites such as ticks before they attach, as a reflection of a central programming or timing mechanism. Based on behavioural observations of Thomson's gazelle, Gazella thomsonii , Grant's gazelle, Gazella granti , impala, Aepyceros melampus , and wildebeest, Cannocheates gnu , in Kenya and at the San Diego Wild Animal Park (SDWAP), both models seemed to apply to different aspects of grooming. Presumably, as a reflection of their increased vulnerability to ectoparasites through a greater body surface to mass ratio (body-size principle), Thomson's gazelle were found to groom more frequently than wildebeest. This corresponds to a reportedly smaller number of ticks per m 2 surface area in Thomson's gazelle. Territorial males groomed less frequently than conspecific females and bachelor males, presumably relfecting their need to remain vigilant over females (vigilance principle). Within-species grooming was less in a low-parasite environment (SDWAP) than in a high-parasite environment (Kenya), reflecting both a decreased exposure to parasites (habitat principle) and a decrease in programmed grooming. Impala, which typically inhabit tick-infested woodland areas, orally groomed themselves more than the size-matched Grant's gazelle comparison species, and also engaged in a unique form of reciprocal allogrooming of the head and neck. That the impala allogrooming may also have a tick-removal function was supported by the finding that impala scratch-groom the head and neck less than Grant's gazelle.

The effectivity of the scrub technique used in quantitative parasite ecology to collect ectoparasites from mammalian skins was evaluated. This was done by reprocessing already scrubbed skins with the alkali digestion technique to remove any remaining parasites. The skins of six adult impala (Aepyceros melampus) ewes were used in the study. The results showed that the scrub technique is variable in its effectivity, and on average removed only 30.2% ectoparasites from the skins. It was also shown that the scrub technique is unreliable and more labour intensive and time consuming than the digestion technique, and should preferably not be used in quantitative studies.

The previously unknown life-cycles of Cooperioides hamiltoni and Cooperioides hepaticae parasitic in impala, are recorded. Observations on the morphology of the developmental stages of these two nematode species are described and their habitat as well as their similarities and differences are discussed. C. hepaticae was successfully transferred to domestic sheep. Attempts were also made to transmit C. hamiltoni lo sheep.

The serum concentration of acute phase proteins (APPs) increases dramatically in response to inflammation and tissue injury. APPs are clinically useful in a range of domesticated mammals; however, knowledge is limited in nondomesticated mammals. The detective ability of two assays for each of three potential APPs--serum amyloid A (SAA), C-reactive protein (CRP), and haptoglobin (Hp)--was evaluated in eight species. For SAA, a turbidimetric immunoassay (TIA) demonstrated significant detective abilities in the Asian elephant (Elaphas maximus), impala (Aepyceros melampus), musk ox (Ovibos moschatus), and chimpanzee (Pan troglodytes), as did an SAA enzyme-linked immunosorbent assay (ELISA) in the impala. For CRP, both TIA and ELISA had significant detective abilities in the chimpanzee. For Hp, a colorimetric assay demonstrated significant detective abilities in impala, musk ox, sitatunga (Tragelaphus spekeii), and chimpanzee, as did the Hp ELISA in the impala, musk ox, and sitatunga. In conclusion, these results suggest that assays for detection of relevant APPs in several nondomesticated animals are available.

Summary A longitudinal study was performed in the Kruger National Park, South Africa to investigate the role of impala (Aepyceros melampus) in maintaining SAT serotypes of foot-and-mouth disease (FMD) virus. Three sampling sites with different histories of FMD outbreaks in impala and also of varying ecology were chosen. At three monthly intervals approximately 40 impala were bled and examined for clinical FMD at each of these sites for a period of 6 years, followed by 4 years of less frequent sampling. During the 10 years of the study, clinical disease was only observed once at a single sampling site, while at two of the three locations, serological evidence of infection was detected; in one locality this was a frequent occurrence. The discrepancy between clinically evident disease and serological evidence of infection indicated that sub-clinical infection with these viruses may be more regular than previously suspected. Furthermore, there was evidence that either SAT-serotype infection is maintained within local impala populations for prolonged periods or that re-infection of impala by buffalo occurs repetitively, sometimes at frequent intervals. A mixed-effects logistic regression model showed that females and older animals had a higher risk of seropositivity, while summer and autumn also represent periods when there is a heightened risk of seropositivity (as opposed to winter and spring which previous studies had shown to be associated with clinical disease). Comparison of impala and buffalo ratios in the three sampling regions indicated that the higher the impala density, the more likely disease transmission is from buffalo to impala, and that this is independent of buffalo numbers (presumably above an undetermined threshold). This study confirmed the potential role of impala for propagating FMD in southern Africa and this factor should therefore be considered when designing control strategies where wildlife and domestic animals interact.

The phytomass and species composition of the herbaceous layer in preferred grazing areas of zebra Equus burchellii, buffalo Syncerus caffer, waterbuck Kobus ellipsiprymnus, blue wildebeest Connochaetes taurinus, impala Aepyceros melampus and warthog Phacochoerusaethiopicus were investigated within the south-eastern portion of the Kruger National Park. The percentage frequency of herbaceous plants in Decreaser and Increaser categories, as determined by their reaction to different intensities of grazing, was established. The preferred grazing areas of the relevant herbivore species were compared in terms of phytomass, contribution of the Decreaser and Increaser categories, veld condition and degree of utilisation. The grazing areas of buffalo and zebra showed less utilisation than those of the other herbivore species. Warthog and impala were associated with over-utilised areas. It is clear that localised over-utilisation is an integral part of the natural grazing mosaic and should be managed as such in large African conservation areas.

Because impala are commonly exhibited and handreared in zoos and their natural nursing behavior had not previously been studied, we examined nursing and early development in five impala calves housed in a large, naturalistic enclosure. Calves were observed for the first 5 weeks of life during 12-hr continuous watches and 20-min focal animal samples. Total daily suckling time decreased while time grazing and feeding on concentrates increased from 1–5 weeks of age. An increasing proportion of nursing bouts were terminated by the dam as calves matured, with dams terminating almost 70% of bouts during the first week. Suckling success and maternal grooming also decreased after week I, suggesting that impala mothers cut back early on nursing and grooming of offspring. Rapid decline in mother-young spatial proximity and a concomitant increase in calf association with age-mates over time suggests that the mother-young bond is weak and ephemeral in impala. An example of the implications of our results for improving handrearing programs would be that newborn calves should be started on a daylight feeding schedule of one bottle-feeding every three hours, and that they not be allowed to gorge themselves at any one of these feedings.

Game meat has distinct sensory characteristics and favourable fatty acid profiles which differ between species. The SFA's percentage was found to be higher in impala meat (51.12%) than kudu meat (34.87%) whilst the total PUFA was higher in kudu (38.88%) than impala (34.06%). Stearic acid (22.67%) was the major fatty acid in impala and oleic acid in kudu (24.35). Linoleic acid, C20:3n-6 and C22:6n-3 were higher in kudu while C20:4n-6, C20:5n-3 and C22:5n-3 were higher in impala. The PUFA:SFA ratio for kudu (1.22) was higher than for impala (0.73) while impala had a higher n-6 PUFA's to n-3 PUFA ratio (3.76) than kudu (2.20). Kudu was higher in cholesterol (71.42 ± 2.61 mg/100 g muscle) than impala (52.54 ± 2.73 mg/100 g muscle). Sensory evaluation showed impala had a more intense game aroma and flavour while the initial juiciness of cooked samples of kudu was higher. The results show kudu and impala can be marketed for their unique flavours and aromas as well as being a healthy substitute for other red meats.

Two impala (Aepyceros melampus) carcasses were subjected to varying degrees of mutilation by large mammalian scavengers. Daily observations of carcass surface condition revealed that the timing and frequency of scavenger feeding visits had a profound effect upon carcass decomposition: a single feeding visit 10 days after death at the first carcass produced an extended sequence of decay. At the second carcass, repeated visits two, three and five days after death, resulted in a faster rate of decay. The colonization of the carcasses by necrophagous insects was characterized by a distinct sequence of arrival. The abundance of Calliphoridae, Histeridae and Dermestidae was correlated with surface condition at both carcasses. Thus, these insects provided an indication of the state of carcass decay. However, as the rate of decomposition was different at each carcass, the temporal abundance of necrophagous insects was not the same at both carcasses. The results suggest that the temporal abundance of key insect families provide an inaccurate indication of the time of death in circumstances when carcasses have subsequently been mutilated.

The physiological response resulting from manual restraint in veld and bomakept impala was investigated by determining haematocrit, lactate, glucose, total protein and lipid, osmolarity, cortisol, and catecholamine values at times 0, 5, and 10 minutes. Blood was also obtained at time 10 from animals manually restrained but without repetitive sampling. The results indicate that manual restraint resulted in a physiological response in both veld and boma-kept animals but that the reactions were different depending on whether the impala were naive. In addition, repetitive blood sampling did not aggravate the response.

1. 1. The effects of tranquillizers on the physiological responses of wild boma-kept impala ( Aepyceros melampus melampus ) to repeated capture and handling were investigated. 2. 2. The study involved three separate trials in which both a treatment and a control group of impala were confined in a boma and caught regularly for blood sampling. 3. 3. The plasma and blood were analysed for variables associated with the stress response namely, lactate, glucose, total protein, total lipid, cortisol and total catecholamine concentrations as well as haematocrit and osmolality. 4. 4. In each trial, both groups displayed increased lactate, glucose, cortisol, total catecholamines, osmolality and haematocrit but there was no difference between control or treatment groups. 5. 5. These results indicate that none of the tranquillizers used was effective in suppressing the physiological responses of boma-kept impala to capture and handling. However, the observable sedatory effects of these drugs may be beneficial in the initial adaptation of wild impala to confinement if they are not subjected to additional Stressors.

This observational field study used intermittent still photography to examine the distribution of motor laterality in images of two African grazing quadruped species: plains zebras (Equus burchellii) and impalas (Aepyceros melampus). Zebra images (n=708) had a laterality index of −6.21 and a Z-score of −1.65 (p=.098). Impala images (n=318) had a laterality index of −18.87 and a Z-score of −3.36 (p=.0008). The weak left motor bias in zebras aligns with that reported in domestic horses using a related method.

Determination of carrying capacity for mixed‐ or multi‐species grazing systems is complex. Commonly, each species is compared to the standard large stock unit (LSU) used in conventional agriculture. However, this approach does not allow for ecological separation, and thus overlooks the potential for using the specialised and complementary resource‐use habits of wild ungulates to maximise veld utilisation. The aim of this study was to quantify the overlap in ungulate resource‐use on a game ranch, and to demonstrate how these indices of overlap can be incorporated into substitution ratios for calculating stocking rates. Habitat utilisation patterns of Burchell's zebra (Equus burchelli,), blue wildebeest (Connochaetes taurinus), eland (Taurotragus oryx), gemsbok (Oryx gazella), giraffe (Giraffa camelopardalis), impala (Aepyceros melampus), kudu (Tragelaphus strepsiceros), and warthog (Phacochoerus aethiopicus), were studied on the Messina Experimental Farm. Indices of overlap were determined for spa...

Behavioural thermoregulation is an animal's primary defence against changes in the thermal environment. We aimed to validate a remote technique to quantify the thermal environment behaviourally selected by free-ranging ungulates. First, we demonstrated that the temperature of miniature, 30 mm diameter, black globes (miniglobes) could be converted to standard, 150 mm diameter, black globe temperatures. Miniglobe temperature sensors subsequently were fitted to collars on three free-ranging ungulates, namely blue wildebeest (Connochaetes taurinus), impala (Aepyceros melampus) and horse (Equus caballus). Behavioural observations were reflected in animal miniglobe temperatures which differed from those recorded by an identical miniglobe on a nearby exposed weather station. The wildebeest often selected sites protected from the wind, whereas the impala and the horse sheltered from the sun. Nested analysis of variances revealed that the impala and horse selected significantly less variable environments than those recorded at the weather station (P

The intestinal helminth parasites of the impala from the Kruger National Park, South Africa, were examined to describe the parasite community structure. Demographic variation and the associated differences in behavior were used to further investigate the patterns of community composition. Monte Carlo simulations were performed to test for differences in species richness and mean abundance between the various demographic groups, and nonmetric multidimensional scaling ordination was used to compare community composition. Seventeen species of nematodes, totaling more than 1.3 million worms, were recovered. Males harbored a greater number of nematode species than did females, but adult females were more heavily infected than their male counterparts. Lambs acquired infections early in life, and their parasite community composition rapidly approached that of the older animals. The parasite community in the juvenile and adult males was significantly different from the community of the adult females. These data suggest that social and feeding behavior of the different age-sex classes structure the parasite component community of impala. Additionally, the distinction between common and rare parasites, and their classification in other herbivores, implies complex transmission dynamics that includes extensive species sharing within the Kruger National Park.

Large- to medium-sized African ungulates are often studied in conservation areas, ignoring the fact that most African landscapes are nowadays heavily impacted by agricultural and pastoralist practices. The present study emphasises the wealth of information obtained from studying a remnant population of a medium-sized ungulate, the impala (Aepyceros melampus), on degraded rangelands in Rwanda. Compared with impala occurring under similar climatic conditions in Serengeti National Park in Tanzania, the study population showed a marked reduction in daytime activity, absence of a mid-day resting phase, and a slight increase in activity towards the late afternoon. This pattern was not directly correlated with daily variation in human activity. It is argued that hunting/poaching leads impala to seek shelter to such a degree that any daytime rhythmicity in activity patterns is lost and that increased afternoon activity reflects a shifted cost-benefit ratio of hiding versus foraging, as hungry individuals are more likely to take risks. Indeed, impala were more likely to encounter cattle herds and their herdsmen towards the afternoon. The study augments understanding of behavioural flexibility, potential for habituation and adaptation to human-induced habitat alterations in impala and highlights a possible function of rangelands as dispersal corridors for African wildlife populations.

We studied the spatial and temporal habitat use of impala in Botswana's Okavango Delta at landscape level with the aid of satellite imagery, with minimal fieldwork. We related remotely sensed vegetation to impala habitat preferences, by first distinguishing three vegetation types through a multi-temporal classification, and dividing these into subclasses on the basis of their Normalized Difference Vegetation Index (NDVI). This indicator for abundance and greenness of biomass was assessed for wet and dry season separately. Similarly, habitat use was assessed for both seasons by allocating vegetation classes to bimonthly impala observations. Impala distribution patterns coincided with NDVI-based subclasses of the landscape, nested within broad vegetation types, to which impala did not show a marked seasonal response. We suggest that this methodology, using limited field data, offers a functional habitat classification for sedentary herbivores, which appears particularly valuable for application in extensive areas with high spatial variability, but with restricted access.

An updated list of helminth parasites of impala ( Aepyceros melampus ), blue wildebeest ( Connochaetes taurinus ), sable antelope ( Hippotragus niger ), waterbuck ( Kobus ellipsiprymnus ), common duiker ( Sylvicapra grimmia ), eland ( Taurotragus oryx ), tsessebe ( Damaliscus lunatus ) and bushbuck ( Tragelaphus scriptus ) is given based on the results of a study of helminths of antelope reared with cattle. The helminths are listed according to host species. The list will constitute an update of the helminth checklist reported by Jooste (1989). New helminth species were recorded in impala, tsessebe, sable antelope, waterbuck, common duiker and bushbuck. Zimbabwe Vet. J. Vol.33(2) 2002: 109-115

The adult male and female and first instar nymph of the sucking louse Linognathus weisseri n. sp. are described. This louse was collected from impalas, Aepyceros melampus, at three localities in Limpopo Province, and at three in Mpumalanga Province, South Africa. Although it usually accounted for only a small proportion of the total louse burden, its overall prevalence exceeded 27 %. Its prevalence on adult male impalas (9 %) was significantly lower (P = 0.004) than that on adult females (39 %), but did not differ among age classes. However, the intensity of L. weisseri infestation was higher on lambs than on yearlings and adults, and peaked on impalas in late winter to early summer. Five species of lice are now known to parasitize impalas and a key for distinguishing adults of these species is included.