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Human activity shapes landscape heterogeneity, which can influence where and how species interact. In African savannas, human-mediated changes to woody cover affect perceptions of risk and foraging decisions by large herbivores. Through cafeteria-style feeding trials, we presented two common, browsing ungulates (Guenther's dik-dik [Madoqua guentheri] and impala [Aepyceros melampus]) with branches from four tree species that varied in their relative investment in mechanical and chemical defenses. We conducted trials in habitats that were perceived as risky to either dik-dik (i.e., open habitat) or impala (i.e., bushland habitat). We found that dik-dik preferred to eat thorny trees low in tannin content within bushland habitats, while the larger-bodied impala preferred tannin-rich but thorn-less branches within open habitats. Risk-induced habitat use homogenized browsing pressure in the lower canopy, but increased heterogeneity in browsing pressure in the upper canopy. In addition, plant defenses neutralized the effects of risk, and foraging height on browsing pressure. Our results demonstrate how foraging experiments—typically the basis for field studies on species coexistence—can be extended to make inferences about consumer-resource dynamics in human-modified landscapes.

Unmanned Aerial Systems (UAS) are increasingly being used recreationally, commercially and for wildlife research, but very few studies have quantified terrestrial mammalian reactions to UAS approaches. We used two Vertical Take-off and Landing (VTOL) UAS to approach seven herbivore species in the Moremi Game Reserve, Botswana, after securing the relevant permissions. We recorded responses to 103 vertical and 120 horizontal approaches, the latter from three altitudes above ground level (AGL). We ran mixed logistic regressions to identify factors triggering (i) any response and (ii) an evasive response. We included effects of activity, altitude, direction of approach, distance, habitat, herd type, herd size, other species, target species, time, VTOL type and wind strength. Response triggers were linked to altitude, distance, habitat and target species. Elephant (Loxodonta africana), giraffe (Giraffa camelopardalis), wildebeest (Connochaetes taurinus) and zebra (Equus quagga) were most affected by VTOL approach, impala (Aepyceros melampus) and lechwe (Kobus leche) were least responsive, and tsessebe (Damaliscus lunatus) displayed intermediate sensitivity. VTOLs flown lower than 60 m AGL and closer than 100 m horizontal distance from target animals triggered behavioural responses in most species. Enforced regulations on recreational UAS use in wildlife areas are necessary to minimise disturbance to terrestrial mammals.

The majority of Africa's parks and conservation areas have a vast road network, facilitating motorized vehicle game viewing. These roads have an influence that is both road type‐ and species‐specific, on the surrounding ecosystem. Due to their higher traffic volumes, we hypothesized that tar roads and their immediate surrounds within the Kruger National Park, South Africa, are avoided to a greater extent by medium‐to‐large mammals than comparable dirt roads in the park. We systematically recorded the presence of medium‐to‐large mammal species from our vehicle, recording data at 401 tar and 369 dirt road stops in the Kruger National Park. In addition to species presence, we also estimated the proximity of animals to the road, as well as herd sizes. Our results indicate an equal likelihood of viewing the commonly recorded medium‐to‐large mammal species from both road types. The likelihood of observing larger herd sizes was also similar between tar and dirt roads for the three most commonly observed species, African elephant (Loxodonta africana), impala (Aepyceros melampus), and plains zebra (Equus quagga), and the likelihood of viewing impala and zebra close to the road also did not differ between tar and dirt roads. However, elephant was observed more often close to tar roads, compared to dirt roads. We interpreted this as the result of potentially increased woody cover associated with more water runoff in close proximity to tar roads compared with dirt roads. Our results not only have ecological significance, supporting the notion that many of the park's species are habituated to human infrastructure, but also management implications, informing park officials about the influence of road traffic and road type on wildlife distributions., The likelihood of viewing the common mammal species in the Kruger National Park (KNP), South Africa, is equal from tar and dirt roads. The likelihood of viewing large herds of elephant (Loxodonta africana), impala (Aepyceros melampus), and zebra (Equus quagga) is equal from tar and dirt roads in KNP. The likelihood of close‐up sightings of impala and zebra is equal from tar and dirt roads, but close‐up elephant sightings are more likely next to tar than dirt roads at KNP.

Enterotoxemia is an important issue in various zoological taxa. In this study, serologic responses over a 1-yr period after vaccination with a multivalent clostridial vaccine were evaluated in 10 adult springboks (Antidorcas marsupialis), 12 impalas (Aepyceros melampus), seven alpacas (Vicugna pacos), and five red-necked wallabies (Macropus rufogriseus). Antibody production to the Clostridium perfringens type D epsilon toxin component of the vaccine was measured using an indirect enzyme-linked immunosorbent assay and determined as the percentage of inhibition (% inhib). Initial % inhib was (0.01-18.9)%. All animals received initial vaccination with a booster vaccine 4 weeks apart. Serum samples were collected at T0 (nonvaccinated), 15, 30, 60, 180, and 360 days postvaccination (dpv) for analysis. The vaccine induced a high antibody response that peaked at 15, 30, and 60 dpv in springboks, 30 and 60 dpv in impalas (P < 0.01), and 60 dpv in alpacas and wallabies (P < 0.01). The booster vaccine was followed by a high antibody response, which slowly decreased with time. The antibody response was significantly higher at 360 dpv than at T0 in wallabies and alpacas (P < 0.01). In impalas and springboks, it appeared that a booster every 6 mo might be required to maintain an antibody response above baseline (P < 0.01). Because no challenge studies were performed, it is unknown whether the measured humoral immune responses would have been protective. Further research is warranted to investigate protective effects of antibodies to inoculation challenge in nondomestic species.

The objective of this study was to determine the influence of three production systems (intensive, semi-extensive and extensive) with differing nutrition on the descriptive sensory and fatty acid profiles of sub-adult (±15–18 months old) male impala longissimus thoracis et lumborum (LTL) muscles. The discriminant analysis plot showed that extensively produced impala had a sensory profile distinct from the intensive and semi-extensive system impala. Extensively produced impala had the highest sensory ratings for overall intensity, gamey, beef-like, herbaceous, and sweet-associated aroma and flavor of their meat. The intensive and semi-extensive system impala did not differ for most of the sensory attributes, except for higher ratings for gamey flavor, liver-like flavor, tenderness and mealiness, and lower ratings for residue found in semi-extensive system impala. The overall aroma and flavor intensities of impala meat in general had strong positive correlations with gamey, beef-like, herbaceous, and sweet-associated aromas and flavors, however, marketing should be adjusted depending on the nutrition received by the impala, to allow consumers to select their preferential sensory profile. Impala meat from all three production systems had low fat contents (&lt, 2%), and desirable fatty acid profiles.

Simple Summary Until now, the milk composition of impala and tsessebe has been unknown. Our study showed that the composition of impala milk was 5.56 ± 1.96% fat, 6.60 ± 0.51% protein, and 4.36 ± 0.94% lactose, and that of tsessebe milk was 8.44 ± 3.19%, 5.15 ± 0.49%, and 6.10 ± 3.85%, respectively. The fatty acid composition and protein properties also differed. The data of these two species were subjected to an interspecies comparison with 13 other antelope species by statistical methods. This showed that the milk of tsessebe is similar to that of its relatives of the Alcelaphinae sub-family. Although the impala is a close relative of the Alcelaphinae, its milk composition finds comparison with a different sub-class, the Hippotraginae. The information contributes to the phylogenetic properties of milk and milk evolution. Abstract The major nutrient and fatty acid composition of the milk of impala and tsessebe is reported and compared with other Bovidae and species. The proximate composition of impala milk was 5.56 ± 1.96% fat, 6.60 ± 0.51% protein, and 4.36 ± 0.94% lactose, and that of tsessebe milk was 8.44 ± 3.19%, 5.15 ± 0.49%, and 6.10 ± 3.85%, respectively. The high protein content of impala milk accounted for 42% of gross energy, which is typical for African Bovids that use a “hider” postnatal care system, compared to the 25% of the tsessebe, a “follower”. Electrophoresis showed that the molecular size and surface charge of the tsessebe caseins resembled that of other Alcelaphinae members, while that of the impala resembled that of Hippotraginae. The milk composition of these two species was compared by statistical methods with 13 other species representing eight suborders, families, or subfamilies of African Artiodactyla. This showed that the tsessebe milk resembled that of four other species of the Alcelaphinae sub-family and that the milk of this sub-family differs from other Artiodactyla by its specific margins of nutrient contents and milk fat with a high content of medium-length fatty acids (C8–C12) above 17% of the total fatty acids.

BackgroundThe rutting vocal display of male impalaAepyceros melampusis unique for its complexity among ruminants. This study investigates bouts of rutting calls produced towards potential mates and rival males by free-ranging male impala in Namibia. In particular, a comparison of male rutting and alarm snorts is conducted, inspired by earlier findings of mate guarding by using alarm snorts in male topiDamaliscus lunatus.ResultsRutting male impala produced 4–38 (13.5 ± 6.5) rutting calls per bout. We analyzed 201 bouts, containing in total 2709 rutting calls of five types: continuous roars produced within a single exhalation-inhalation cycle; interrupted roars including few exhalation-inhalation cycles; pant-roars distinctive by a pant-phase with rapidly alternating inhalations and exhalations; usual snorts lacking any roar part; and roar-snorts starting with a short roar part. Bouts mostly started and ended with usual snorts. Continuous roars were the shortest roars. The average duration of the exhalatory phase was longest in the continuous roars and shortest in the pant-roars. The average fundamental frequency (49.7–51.4 Hz) did not differ between roar types. Vocal tract length, calculated by using measurements of the first four vocal tract resonances (formants), ranged within 381–382 mm in all roar types. In the studied male impala, rutting snorts within bouts of rutting calls were longer and had higher values of the upper quartile in the call spectra than alarm snorts produced towards potential danger.ConclusionsAdditional inhalations during the emission of the interrupted and pant-roars prolong their duration compared to the continuous roars but do not affect the fundamental frequency or the degree of larynx retraction while roaring. Alarm snorts are separated from one another by large intervals, whereas the intervals between rutting snorts within bouts are short. Sometimes, rutting snorts alternate with roars, whereas alarm snorts do not. Therefore, it is not the acoustic structure of individual snorts but the temporal sequence and the occasional association with another call type that defines snorts as either rutting or alarm snorts. The rutting snorts of male impala may function to attract the attention of receptive females and delay their departure from a male’s harem or territory.

Potent opioids are known to cause negative alterations to the physiology of immobilised antelope. How these effects differ between species has not been studied. This study aimed to compare time to recumbence and effects of opioid-based immobilisation on the physiology of impala (Aepyceros melampus) and blesbok (Damaliscus pygargus phillipsi). Eight animals of each species were immobilised, with 0.09 mg/kg etorphine and 0.09 mg/kg thiafentanil respectively, in a randomised two-way cross-over study. Variables measured and analysed by means of a linear mixed model included time to recumbence, heart rate, respiratory rate, arterial blood pressure, blood gases, lactate and glucose. In blesbok, mean time to recumbence was not significantly different with either drug (2.5 minutes and 2.2 min, respectively), but in impala thiafentanil achieved a shorter time to recumbence (2.0 min) than etorphine (3.9 min). Mean heart rates of immobilised impala were within reported physiological limits, but lower in immobilised blesbok when both opioids were used (35 beats/min to 44 beats/min vs. 104 ± 1.4 beats/min resting heart rate). Impala developed severe respiratory compromise and hypoxaemia from both opioids (overall mean PaO2 values ranged from 38 mmHg to 59 mmHg over 30 min). In contrast, blesbok developed only moderate compromise. Therefore, significantly different species-specific physiological responses to potent opioid drugs exist in blesbok and impala. Given that these different responses are clinically relevant, extrapolation of immobilising drug effects from one species of African ungulate to another is not recommended.

Although large herbivore habitat use has been extensively studied, more information is still required on the use of heterogeneous vegetation types. Over 3 y we carried out monthly road transects in the Zambezi National Park (ZNP), Zimbabwe, to determine the impala density in each of five vegetation types. In addition we determined grass and browse chemical composition to test if at the time the impala switches from grass to browse, grass nutritive quality had declined below that of browse. Furthermore, grass height was measured in the five vegetation types. The impala used mixed, acacia and terminalia vegetation types, which constituted 37% of the protected area and avoided grassland and the predominant Zambezi teak (60% of ZNP) vegetation types. At the time of the diet switch by the impala from grass to browse, woody plant leaf nutritive quality was higher than grass in terms of nitrogen, calcium and acid detergent fibre content. The three vegetation types used by the impala had short to medium grass height. We concluded that when the impala switched from grass to browse the grass nutritive quality was lower than that of the browse.

Long-term growth rates of ungulate populations can be affected where disproportionate mortality occurs to adult females through predation. To investigate differences between lions (Panthera leo) and wild dogs (Lycaon pictus) in relative selection for female prey, we analysed ranger records for impala (Aepyceros melampus) and kudu (Strepsiceros zambesiensis) from Madikwe and Pilanesberg Nature reserves, South Africa. Each kill was categorized by sex of killed animal (female, male), likely predator (lion, wild dog) and season of kill (early wet, late wet, early dry, late dry). Our findings at Madikwe and Pilanesberg show that wild dog kill data for both kudu and impala are female-biased whereas lion kill data for the two ungulate species are male-biased.

Understanding a species’ diet can be critical for effective conservation. While several traditional methods for assessing raptor diet exist, many pose inherit biases and often require extensive fieldwork that can limit sample sizes and the geographic scope of studies. This is especially true for species that nest at low densities (e.g., large eagles). Recently, several studies have demonstrated the value of web-sourced photographs in tackling ecological and evolutionary questions. Specialized software (e.g., MORPHIC) has been developed to systematically extract Google Images for this purpose. We used this approach to explore the diet of Martial Eagles (Polemaetus bellicosus). A shortage of prey is one of the proposed hypotheses for recent population declines across their range. Of the 4,872 photographs selected by MORPHIC, 254 were usable (5%). Birds, mammals, and reptiles each contributed similarly to overall identified prey. Helmeted Guineafowl (Numida meleagris) were the most important bird prey identified (12% of overall prey). The 4 most important mammalian prey species were Thompson’s gazelle (Eudorcas thomsonii; 5%), impala (Aepyceros melampus; 4%), common duiker (Sylvicapra grimmia; 4%), and banded mongoose (Mungos mungo; 4%). Reptile prey was dominated by monitor lizards (Varanus spp.; 21%). Prey class proportions differed significantly by regions with mammalian prey being more common in eastern Africa and reptile prey being more common in southern Africa. Within South Africa, reptile prey proportion was greater in the east than in the west. These corroborate existing prey composition studies. Prey composition differed between age classes, with adult eagles preying on more birds than non-adults. There was no significant difference in the average estimated prey weight by eagle age or feeding position (ground, perched, or flying). Our results suggest that this approach may offer a useful method to explore the diet for raptor species that are well photographed across their range, at minimal cost and research effort.

Sympatric occurrence of puku (Kobus vardonii) and impala (Aepyceros melampus) characterises large parts of the protected areas in Zambia. The present study assessed traits of the populations as well as spatial and dietary overlap of both antelopes in Kafue National Park and adjacent Game Management Areas in western Zambia. Data were collected via distance sampling along line transects (population and distribution) and via microhistological analyses of dung (diet). Hunting activities might result in fewer males in both antelopes in the Game-Management areas. During the cool dry season there was considerable spatial overlap between puku and impala. However, puku are more abundant in grassland areas, while impala reach highest population densities in intermediate habitats. The diet of puku was characterised by high amounts of grasses during both the cool dry season and the late rainy season. Impala shifted from browsing during the cool dry season to a more grazing diet during the rainy season. This study found niche partitioning via habitat and diet as a key to understand the coexistence of these antelopes and improves our knowledge of Zambian Wildlife.

Based on fossil hair identified from brown hyaena (Parahyaena brunnea) coprolites from Middle Pleistocene deposits at Gladysvale Cave in the Sterkfontein valley, South Africa, the scale pattern and cross-sectional morphology of fossil hair conclusively established that brown hyaenas shared the Sterkfontein valley with humans, warthog (Phacochoerus aethiopicus), impala (Aepyceros melampus), Burchell’s zebra (Equus quagga, formerly burchelli), greater kudu (Tragelaphus strepsiceros) and black wildebeest (Connochaetes gnou). These animals are associated with mixed savanna biomes. Even though it cannot be attributed to which hominin species the fossil hair belong, they, however, lived in a mixed savanna environment.

Territoriality is a common behavioural adaptation, widespread among ungulates. Here, we tested the hypothesis that territorial individuals have higher glucocorticoid concentrations than non-territorial bachelors, in wild impala (Aepyceros melampus) in the Serengeti ecosystem. We also investigated how the relationship between territoriality and glucocorticoid levels is influenced by environmental context, specifically, food quality, population density (i.e., territory defence intensity), and herd size (i.e., mate defence effort). We collected 139 faecal samples over 4 years and analysed these for faecal glucocorticoid metabolites (FGMs). We used Normalised Difference Vegetation Index (NDVI) as a proxy for food quality, and population density was based on aerial surveys. Territorial males had, on average, higher FGM concentrations than bachelors. Increased food quality did not affect FGM levels in territorial males, but decreased FGM levels in bachelors by 78%. Greater population density increased FGM levels by 47%, but this effect was not different between territorial and bachelor males. Herd size did not affect FGM levels in territorial males. While elevated GC levels are often suggested to be repercussions of being territorial, our findings support the hypothesis that elevated GC levels may be beneficial and act as a facilitator of a male’s reproductive potential. The elevated GC levels may increase the ability of territorial males to maintain a territory by increasing energy mobilisation and metabolic rate, ultimately increasing their reproductive fitness. Appreciating that long-term increases in GC levels are not simply costly but may have an adaptive, potentially facilitating role in an animal’s life history is key to understanding HPA-axis reactivity and its potential in eco-physiological studies.

Human activities can lead to various changes in wildlife populations’ behaviour and dynamics. Understanding specific responses to disturbances can help conservation management better protect wildlife populations to coexist with local communities. Here, we studied the response of a model ungulate species, the impala (Aepyceros melampus), to different types of human activities in the Serengeti ecosystem. Impala were studied in central Serengeti National Park (CSNP), an area with relatively low human disturbance, and, with increasing levels of human disturbance, in western Serengeti National Park (WSNP), Grumeti Game Reserve (GGR), Ikona Wildlife Management Area (IWMA), and Loliondo Game Controlled Area (LGCA); pastoralism and/or hunting are the main disturbances in these areas. We hypothesised that in the exploited GGR, IWMA and LGCA areas, 1) impala would spend more time on costly behaviours, 2) sex ratios would be more female skewed, and 3) group sizes, reproduction and recruitment ratios would be lower compared to CSNP. We found that impala spent less time resting in IWMA and LGCA, as well as a significantly lower proportion of males, and lower reproduction and recruitment ratios in LGCA. Impala synchronized their behaviour, increasing their social cohesion potentially resulting in more efficient anti-predator strategies. Human activities induced a behavioural response in impala, indicating that in less regulated areas where pastoralism and hunting are allowed, these disturbances can potentially affect impala population persistence. These results highlight the importance of protected areas for wildlife populations, and the need for continuous monitoring of the impala and other ungulate populations in less regulated areas, as the underlying anthropogenic disturbances are likely impacting diverse species. © 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ).

Wildlife hosts many pathogens of economic importance and is considered as a reservoir of important tick-borne diseases of livestock in southern Africa. The species composition of ticks parasitizing buffalo (Syncerus caffer), impala (Aepyceros melampus) and elephant (Loxodonta africana) was investigated in five protected parks in the Zambezi valley, Zimbabwe. A total of 1104 adult ticks was collected from 75 adult animals comprising five buffaloes, five elephants and five impalas drawn from five protected wildlife parks. Five tick species belonging to two genera were recovered, with Rhipicephalus decoloratus being the most prevalent species in all the three animal groups. Amblyomma hebraeum was only recovered from buffaloes whereas Rhipicephalus zambeziensis was recovered from buffalos and elephants. Significant differences in mean tick species distribution and concentration were observed amongst the wildlife parks and these appeared to be influenced by the number of hosts in each park. The study revealed that buffaloes are the major host of R. decoloratus in the Zambezi valley. The presence of these ixodid ticks within the Zambezi valley may have significant ecological and economic impacts on wildlife conservation, domestic animals and human health.

Trophy hunting may influence wildlife populations in many ways, but these effects have received little consideration in many of Africa’s protected areas. We assessed the effects of trophy hunting on group size, behaviour, flight initiation distance, sex ratio and calf recruitment rate in two model species, impala (Aepyceros melampus) and greater kudu (Tragelaphus strepsiceros), in Rungwa Game Reserve (RGR), Tanzania. The adjoining Ruaha National Park (RNP) served as a control site, since only ecotourism is permitted. Road transects were driven and data recorded immediately upon sighting animals. Both impala and greater kudu had higher flight initiation distances, smaller group size, lower calf recruitment rates and higher levels of vigilance behaviour in RGR compared to those in RNP. Sex ratios did not differ between the two areas. The observed differences are ascribed to the direct and indirect effects of trophy hunting in RGR. Low calf recruitment rates in RGR are of concern, as this may directly compromise population growth rates. Long-term studies may therefore be required to assess how hunted populations are affected by different hunting intensities and at what point this may threaten population persistence. This work is licensed under a Creative Commons Attribution 4.0 License.

Foraging behaviour plays a key role in the interaction between herbivores and vegetation, their predominant food source. Understanding this interaction is crucial to providing information that is useful for conservation of herbivores. The objective of this study was to determine how sward height influences functional response and movement patterns of free ranging wild impala and zebra at the Kenya Wildlife Service Training Institute. The study was conducted for 3 months. Sward height is an important parameter that indicates how intensive a sward has been grazed and it influences intake rate through its effect on bite size. Bite size, instantaneous intake rate, specific mass intake rate and feeding station interval for impala and zebra increased with sward height. Sward height in combination with an animal's sex was found to have a profound effect on specific mass intake rate in impala. Zebra had a longer feeding station interval and lower stepping rate in tall swards compared to impala. Despite differences in their specific body mass and digestive strategies, impala and zebra maximized their intake rates in tall swards as a trade-off among the swards. Tall swards are therefore critical in the study area and should be protected from bush encroachment which is a persistent problem. 2017 John Wiley & Sons Ltd.

Understanding how wildlife responds to road and traffic is essential for effective conservation. Yet, not many studies have evaluated how roads influence wildlife in protected areas, particularly within the large iconic African National Parks where tourism is mainly based on sightings from motorized vehicles with the consequent development and intense use of roads. To reduce this knowledge gap, we studied the behavioral response and local spatial distribution of impala Aepyceros melampus along the heterogeneous (with variation in road surface type and traffic intensity) road-network of Kruger National Park (KNP, South Africa). We surveyed different types of roads (paved and unpaved) recording the occurrence of flight responses among sighted impala and describing their local spatial distribution (in relation to the roads). We observed relatively few flight responses (19.5% of 118 observations), suggesting impalas could be partly habituated to vehicles in KNP. In addition, impala local distribution is apparently unaffected by unpaved roads, yet animals seem to avoid the close proximity of paved roads. Overall, our results suggest a negative, albeit small, effect of traffic intensity, and of presence of pavement on roads on the behavior of impala at KNP. Future studies would be necessary to understand how roads influence other species, but our results show that even within a protected area that has been well-visited for a long time, wildlife can still be affected by roads and traffic. This result has ecological (e.g., changes in spatial distribution of fauna) and management implications (e.g., challenges of facilitating wildlife sightings while minimizing disturbance) for protected areas where touristic activities are largely based on driving.

Although the rumen microbiome of domesticated ruminants has been evaluated, few studies have explored the rumen microbiome of wild ruminants, and no studies have identified the rumen microbiome in the impala (Aepyceros melampus melampus). In the present study, next-generation sequencing and real-time polymerase chain reaction were used to investigate the diversity and density of the bacteria and methanogenic archaea residing in the rumen of five adult male impalas, culled during the winter dry season in Pongola, South Africa. A total of 15,323 bacterial 16S rRNA gene sequences (from five impala), representing 3,892 different phylotypes, were assigned to 1,902 operational taxonomic units (OTUs). A total of 20,124 methanogen 16S rRNA gene sequence reads (from four impala), of which 5,028 were unique, were assigned to 344 OTUs. From the total sequence reads, Bacteroidetes, Proteobacteria, and Firmicutes were the most abundant bacterial phyla. While the majority of the bacterial genera found were unclassified, Prevotella and Cupriavidus were the most abundant classified genera. For methanogens, the genera Methanobrevibacter and Methanosphaera represented 94.3% and 4.0% of the classified sequences, respectively. Most notable was the identification of Methanobrevibacter thaueri-like 16S rRNA gene sequence reads in all four impala samples, representing greater than 30% of each individual's total sequences. Both data sets are accessible through NCBI's Sequence Read Archive (SRA), under study accession number SRP [048619]. The densities of bacteria (1.26 × 10(10)-3.82 × 10(10) cells/ml whole rumen contents) and methanogens (4.48 × 10(8)-7.2 × 10(9) cells/ml of whole rumen contents) from five individual impala were similar to those typically observed in domesticated ruminants.

Variation of the intraruminal papillation pattern with diet quality has been described in many ruminant species, but the use of papillation measures as a proxy for habitat quality and nutritional status of animals has not been evaluated. We compared various measures of body condition (body mass, body condition score, kidney fat index, bone marrow fat index, adrenal mass, kidney to adrenal mass ratio), diet quality (%browse, protein and fibre content) and rumen papillation in 106 impalas (Aepyceros melampus) from four different locations in Zimbabwe. The various condition proxies indicated that periods of low diet quality are characterised by a high proportion of browse in the diet of this species. Animals with a high proportion of browse had more voluminous rumens, suggesting a compensation for lower diet quality by increased intake. Macroscopic papillation indices did not yield meaningful significant correlations with diet quality or body condition proxies, and hence, their use for estimating habitat or body condition cannot be advocated. In contrast to previous histological reports, ballooning cells of the Stratum corneum of the ruminal mucosa were more prominent in animals on lower-quality diets. There were significant correlations of the kidney to adrenal mass ratio with other body conditions and with diet quality indices, suggesting that poor body condition and low diet quality represent stressful situations.

Sport hunting may have severe behavioural consequences, and possibly conservation implications for wildlife populations. We used flight initiation distances by two herbivores, impala (Aepyceros melampus) and greater kudu (Tragelaphus strepsiceros) to assess the impacts of sport hunting on their flight behaviour. We compared Gwaai, a designated hunting area adjacent to Hwange National Park, a protected area in Zimbabwe. We aimed to estimate flight initiation distances (FIDs) for impala and kudu as this can be a good measure of hunting effect on behaviour. Our results suggest that impala and kudu are more flight prone in hunting areas than in non-hunting areas. We propose habituation to explain the shorter FIDs in the protected area, and the risk of being shot by hunters the higher FIDs in the hunting area. We concede that more field observations are needed to estimate the distance at which animals will always trigger an immediate flight response from approaching predators (Dmin) and the distance above which prey will not move away from an approaching predator as it is not perceived to be dangerous (Dmax) in our study area. However, we suggest that Dmin is a useful index for wildlife managers to assess predation risk.

Summary Human-mediated changes in habitat structure may disturb predator–prey relationships. We investigated the influence of perimeter fences on the diet of a reintroduced population of African wild dogs Lycaon pictus Temminck 1820 in a 316 km2, fenced reserve in South Africa, by tracking radio-collared individuals during hunting periods to determine dietary composition from observed kills. Nutritional status of impala Aepyceros melampus and kudu Tragelaphus strepsiceros prey, as measured by the percentage of femur marrow fat, was significantly lower than that of unselectively culled individuals. This supports the hypothesis that wild dog predation is at least partially compensatory. Fence-impeded kills (those for which escape was deemed to be compromised by the fence) comprised 40·5% of kills (n = 316), and 54·1% of all edible biomass consumed. Compared with fence-unimpeded kills, fence-impeded kills comprised larger species (32·9 vs. 25·0 kg, W = 25667·0, P ≪ 0·001), older age classes for one prey category (female kudu: Fisher's exact test, P = 0·02, n = 65) and animals in better condition for adult impala males (Mann–Whitney, W = 111·0, P = 0·012, n = 28). Fence-impeded kills also provided greater catch per unit hunting effort (27·3 vs. 12·2 kg km−1; χ2 = 7·89, P = 0·005), resulting in longer interkill intervals. Movement of the pack towards the fence at the start of each hunting period suggested a decision to exploit the advantage that fences conferred for capturing prey. Synthesis and applications. By enabling coursing predators to capture prey that would otherwise have escaped, fences may reduce the compensatory nature of predation, causing shifts in predator–prey dynamics that could influence the ability of small reserves to support such predators. The establishment of larger conservation areas to reduce perimeter-to-area ratios should be encouraged to limit the undesired effects of fences on predator–prey dynamics.

Trophy hunting in ungulates may favour individuals with smaller horns. A decrease in horn/antler size may jeopardize the conservation potential of hunting areas, which would be a major concern in Africa where hunting zones represent over half of the total area of protected lands. We investigated horn length trends of harvested male impalas Aepyceros melampus, greater kudus Tragelaphus strepsiceros and sable antelopes Hippotragus niger, from 1974 to 2008 in Matetsi Safari Area, Zimbabwe. Horn length declined by 4% in impalas, partly because male harvest age decreased. In greater kudus, surprisingly, horn length increased by 14%, while mean age of harvested male greater kudus increased during the study period. Reduced hunting pressure on this species during the study may have allowed males to live longer and to grow longer horns before being harvested. Horn length declined by 6% in sable antelopes, independent of age, suggesting that trophy hunting selected male sable antelopes with smaller horns through time, provided that horn length is heritable. Hunting pressure and trophy value were higher for sable antelopes than for impalas and greater kudus. Accordingly, the decline of horn length in this species was more pronounced. More valuable trophy species, such as sable antelopes, require special attention because they may be exposed to higher hunting pressure, and are therefore more likely to experience a decrease in horn size. (Resume d'auteur)

Underlying mechanisms of sexual segregation amongst ungulates, and Trivers and Willard’s hypothesis that mothers can influence primary sex ratios, continue to be topical theoretical issues. Over two years, using monthly repeated road transects, we determined the habitat and social segregation of male versus female impala (Aepyceros melampus) and kudu (Tragelaphus strepsiceros) in a predator-free, versus a predator-laden, South African reserve. We also determined, by the same technique but over four years, the primary sex ratio of the impala population free from predation. Significant overlap in habitat usage (Schoener’s Index 0.63 to 0.8) was found between the two sexes when free from predation, but not (Schoener’s Index 0.46 to 0.47) when under predation. Whilst occupying the same habitats impala, kudu and wildebeest (Connochaetes taurinus) male and female groups maintained rigid social segregation throughout the year, even when at close quarters. Impala primary sex ratios were significantly biased towards females (male/female = 0.72; χ² = 4.3175, df = 1, p-value = 0.038) in the absence of predation. Our findings suggest that whilst risk of predation is a proximal cause of sexual segregation, thus lending support to the predator-risk hypothesis, the underlying, functional mechanism of sexual segregation is difference in the activity budgets of males versus females (the activity-budget hypothesis).Our findings also suggest that mothers may indeed be able to adjust primary sex ratios, with the postulated driver in this case being an abnormally high density of adult males.

Although the efficacy of triclabendazole treatment against Fasciola gigantica has been shown before in cattle and buffaloes, there appears to be no published report on the efficacy of triclabendazole in impala or other antelope species. As part of a health monitoring programme at Mulungushi International Conference Centre, Lusaka, Zambia, a coprological examination was undertaken to investigate the helminthological status of captive impala (Aepyceros melampus). Of 39 fresh coprological samples, 46% contained F. gigantica. The source of infection was identified to be a fountain within the grounds of the conference centre. Lymnaea natalensis, collected from the study site, were induced to shed cercariae, and were thus confirmed as the snail intermediate host. In managing this disease, triclabendazole at 6 mg/kg was administered together with the feed bait. Water from the pond was drained; vegetation within it cleared and the pond allowed to dry for 1 week before water was replaced. Three weeks post-treatment, faecal examination revealed that the Fasciola had been cleared. To the best of our knowledge, this is a first case of Fasciola spp. infection reported in captive wild impala in Zambia and provides evidence that triclabendazole may be delivered to free-ranging antelope using medicated bait.

A study on the seasonal variation in population structure and status of the African buffalo (Syncerus caffer), the greater kudu (Tragelaphus strepsiceros) and the common impala (Aepyceros melampus) was carried out in the Mana Pools National Park floodplain, Zimbabwe. Data was collected during the wet (February) and dry (September) seasons of 2012. The simple random sampling method was employed in transect placement. A total of 10 transects were sampled. The line transect method was used to estimate dry and wet season populations of buffalo, kudu and impala. Results from the two tailed t-test showed no significant variation for the populations of kudu (P>0.05) and buffalo (P>0.05) with season. However, impala population varied significantly with season (P 0.05). Dry season mean group sizes for buffalo, kudu and impala were 9.8, 3.6 and 14.1 respectively. The population of buffalo declined from 446 in 1995 to 174 in 2012. The populations of kudu and impala showed an increasing trend between 1995 and 2012. Results from this study suggest that seasonal variation in forage availability could be the primary factor influencing the status of herbivores in the MPNP floodplain. There is an urgent need for management to revise staff and ration quotas for herbivores and increase law enforcement efforts to assure the sustainable management of herbivores in MPNP.

This study investigates the presence of Enterocytozoon bieneusi in domestic and wild animals living in the wildlife/livestock interface area of the Kruger National Park (KNP) in South Africa. Fifty fecal samples from domestic calves in rural communities and 142 fecal samples from impala (Aepyceros melampus) and buffalo (Syncerus caffer) in the KNP were analysed for Enterocytozoon bieneusi, using a nested PCR targeting the internal transcribed spacer of the rRNA gene. All wildlife samples were negative for E. bieneusi, whereas nine (18%) calf samples were positive. Three cattle specific genotypes (group 2) were identified, belonging to the known genotypes BEB4 and I, and one novel genotype (BEB3-like). One human-pathogenic genotype (D) was detected in one calf. This is the first study on microsporidia performed in a wildlife/livestock interface area of sub-Saharan Africa. Our findings show that at least one genotype of zoonotic importance is circulating in native cattle in the study area and the rest of the identified microsporidia were host-specific genotypes. Larger studies in domestic animals, humans and wildlife are necessary to assess the public health significance of E. bieneusi in that interface area.

Most populations of wild dogs (Lycaon pictus) are declining across southern and southeastern Africa, and in the Save Valley Conservancy (SVC) the decline appears to be associated with declining populations of prey and increasing numbers of competitors. Identifying the threats to this wild dog population is currently needed to determine the most appropriate conservation actions. We studied the diet composition, breadth and overlap among four sympatric carnivores in SVC: African wild dog, spotted hyaena (Crocuta crocuta), lion (Panthera leo) and leopard (Panthera pardus), using faecal analysis. We found remains of 16 mammalian prey species, ranging from small to large mammals (2–525 kg). The four carnivores had many prey species in common (>70% diet overlap), with impala (Aepyceros melampus) consistently the most frequent. The frequency of occurrence of impala, however, was highest in the diets of wild dogs (74%), and wild dogs were found to have the narrowest standardized dietary niche breadth (0.087). The diets also varied significantly in the contribution of different prey-size categories, with large prey (>100 kg) contributing most to the diets of lions and hyaenas, and small prey (

International audience; In this study, we examined the behavioural, temporal and spatial effects of simulated African wild dog (Lycaon pictus) presence on its two main prey species: kudu (Tragelaphus strepsiceros) and impala (Aepyceros melampus). We spread African wild dog faeces around waterholes and played African wild dog sounds at different intervals to mimic immediate and non-immediate predation pressure. We looked at anti-predator behaviour at both a herd and individual level and distinguished between high-quality (detracts from all other activities), high-cost vigilance and low-quality (used to monitor the surrounding in spare time), low-cost vigilance to determine costs involved. We found that simulated African wild dog presence had little effect on anti-predator behaviour of their free-ranging prey. Only when immediate predation risk was mimicked did kudu invest in (additional) high-quality vigilance, whereas impala showed no response. Regardless of direct cues of African wild dog presence, behavioural adjustments to reduce predation risk were primarily based on environmental factors such as time of the day and broad-scale habitat structure. Predators have been shown to utilize waterholes to hunt, and prey species are therefore likely to maximize anti-predator behaviour in this high-risk environment based on environmental variables affecting predation risk, the main predator within the system, and water requirements, leaving little flexibility to respond to (simulated) African wild dog presence.

The late dry season is a crucial period for grazing ungulates because the nutritional value of the remaining brown grass is lowest then and levels of crude protein and digestible organic matter may fall below the maintenance requirements of herbivores (Owen-Smith, 1982). During this adverse period, mixed feeders like impala (Aepyceros melampus) increase the proportion of browse in the form of the leaves of the woody plants they consume (Owen-Smith & Cooper, 1985). Crude protein levels are generally higher and seasonally more constant in foliage of woody plants than in grasses (Owen-Smith, 1982), but the foliage is commonly defended by tannins or spines that restrict consumption by grazers not adapted to cope with them (Cooper & Owen-Smith, 1985, 1986; Cooper, Owen-Smith & Bryant, 1988). Sable antelope (Hippotragus niger) are predominantly grazers and are distributed throughout southern African savannahs (Estes, 1991; Skinner & Chimimba, 2005) where the dry season is prolonged and ambient temperatures are high before the rains begin. Grass quality is especially poor on infertile, sandy soils (Bell, 1984). Sable typically depend on green grass persisting in drainage sump grasslands or in recently burned areas during the dry season (Estes & Estes, 1974; Parrini & Owen-Smith, 2009). However, contrary to previous reports, we observed a substantial amount of browsing by sable in our study area during the dry season. Here, we quantify the contribution made by browse to the diet of sable in our study area. Methods

There has been an increase in the number of wild ungulates kept in captivity for ecotourism and conservation in Zambia and these animals are susceptible to a number of diseases including gastrointestinal helminth infections. Surveys to determine anthelmintic efficacy to gastrointestinal nematodes in captive-wildlife are not common and there have been no reports of anthelmintic resistance in captive-wildlife in Zambia. This study was carried out to determine the efficacy of the benzimidazole anthelmintic fenbendazole in captive wild impala (Aepyceros melampus) in Zambia. During the month of April 2011, at the end of the rainy season, the faecal egg count reduction test was performed at a private game facility for assessing anthelmintic efficacy of oral fenbendazole and the anthelmintic treatment showed an efficacy of 90%. Haemonchus spp. and Trichostrongylus spp. were the predominant genera present before treatment, but Haemonchus spp. larvae were the only genus recovered from the faecal cultures after anthelmintic treatment. This represents the first documentation of anthelmintic treatment failure in captive wild-antelopes in Zambia. It also demonstrated the ineffectiveness of the common traditional practice of deworming captive-wild antelopes at the end of the rainy season due to the rapid re-infection of impala that occurs due to high pasture infectivity. Suggestions on changes to current anthelmintic use/practices that will make them more efficacious and reduce the possibility of development of anthelmintic resistance in captive wild game in Zambia are also made.

Prey make several behavioural adjustments to minimize the risk of predation by their natural predators. When hunted, however, they may have to adjust their behaviour further or differently to cope with this additional mortality risk. Here, we investigated whether African large ungulates would adjust their behaviour in response to hunting risk (i.e. risk of being shot by human hunters). We predicted that they would shift their use of surface water, a key and scarce resource in African savannas, from day hours to night hours to reduce the risk of encountering human hunters. In Hwange National Park, Zimbabwe, we monitored waterholes to record the temporal drinking niche of three nonhunted ungulates (i.e. impala, Aepyceros melampus, greater kudu, Tragelaphus strepsiceros, sable antelope, Hippotragus niger). We also monitored waterholes in hunting areas in the vicinity of Hwange National Park. In Hwange National Park, the three species avoided waterholes at night, when the risk of natural predation was higher. Conversely, in the hunting areas, all three species visited waterholes more often at night. Impala and greater kudu, however, were less prone to switch towards night-time use of waterholes in hunting areas compared to sable antelope, although all three species were exposed to similar hunting risk. Our results suggest that hunting may force African ungulates to shift their visits at waterholes from day hours towards night hours, but that the magnitude of this shift may be constrained by the predation risk imposed by large nocturnal carnivores. We conclude that species preyed upon by natural predators adjust their antipredator behaviour in response to the additional risk of predation imposed by hunting.

Elephant and impala as intermediate feeders, having a mixed diet of grass and browse, respond to seasonal fluctuations of forage quality by changing their diet composition. We tested the hypotheses that (1) the decrease in forage quality is accompanied by a change in diet from more monocots in the wet season to more dicots in the dry season and that that change is more pronounced and faster in impala than in elephant; (2) mopane (Colophospermum mopane), the most abundant dicot species, is the most important species in the elephant diet in mopane woodland, whereas impala feed relatively less on mopane due to the high condensed tannin concentration; and (3) impala on nutrient-rich soils have a diet consisting of more grass and change later to diet of more browse than impala on nutrient-poor soils. The phosphorus content and in vitro digestibility of monocots decreased and the NDF content increased significantly towards the end of the wet season, whereas in dicots no significant trend could be detected. We argue that this decreasing monocot quality caused elephant and impala to consume more dicots in the dry season. Elephant changed their diet gradually over a 16-week period from 70% to 25% monocots, whereas impala changed diets rapidly (2-4 weeks) from 95% to 70% monocots. For both elephants and impala, there was a positive correlation between percentage of monocots and dicots in the diet and the in vitro digestibility of these forage items. Mopane was the most important dicot species in the elephant diet and its contribution to the diet increased significantly in the dry season, whereas impala selected other dicot species. On nutrient-rich gabbroic soils, impala ate significantly more monocots than impala from nutrient-poor granitic soils, which was related to the higher in vitro digestibility of the monocots on gabbroic soil. Digestibility of food items appears to be an important determinant of diet change from the wet to the dry season in impala and elephants.

Scat analysis is one of the most frequently used methods to assess carnivoran diets and Global Positioning System (GPS) cluster methods are increasingly being used to locate feeding sites for large carnivorans. However, both methods have inherent biases that limit their use. GPS methods to locate kill sites are biased towards large carcasses, while scat analysis over-estimates the biomass consumed from smaller prey. We combined carcass observations and scats collected along known movement routes, assessed using GPS data from four African lion (Panthera leo) prides in the Kruger National Park, South Africa, to determine how a combination of these two datasets change diet estimates. As expected, using carcasses alone under-estimated the number of feeding events on small species, primarily impala (Aepyceros melampus) and warthog (Phacochoerus africanus), in our case by more than 50% and thus significantly under-estimated the biomass consumed per pride per day in comparison to when the diet was assessed using carcass observations alone. We show that an approach that supplements carcass observations with scats that enables the identification of potentially missed feeding events increases the estimates of food intake rates for large carnivorans, with possible ramifications for predator-prey interaction studies dealing with biomass intake rate.

The management of large ungulates in southern Africa necessitates reliable monitoring programmes to direct management action. Monitoring programmes for large ungulates typically rely on spotlight survey methods, but do not address variation in detection rates between surveys or observers. In 2009, we used a multiple observer survey technique to estimate detection probabilities for large ungulates in lowveld savanna habitats in Swaziland. Spotlight detection probabilities for all ungulates ranged between 0.22 and 0.57. Species-specific spotlight detection rates for the two most detected species, impala (Aepyceros melampus) and blue wildebeest (Connochaetes taurinus), were 0.48 and 0.61, respectively. At our open savanna study site, detection rates were higher and abundance estimates were fairly consistent. In our more enclosed savanna habitat, both detection rates and resulting abundance estimates were variable. Our results suggest that when monitoring large ungulate populations, managers should conservatively assume they are missing approximately 50% of the population available for surveying. We recommend that managers consider methods which incorporate multiple observers into survey practices and consider using multiple data sources to assist with population management decisions.

This study determined the prevalence of Cryptosporidium spp. oocysts in faecal samples from elephant ( Loxodonta africana ), buffalo ( Syncerus caffer ) and impala ( Aepyceros melampus ) in the Kruger National Park (KNP) and an adjacent game reserve in South Africa. Two of the study areas were in close proximity to rural communities on the western KNP boundary and the third study area was located in the centre of the KNP. Fresh stool samples ( n = 445) were collected and tested using an immunofluorescent antibody test (IFA) for Cryptosporidium parvum . A total of 278 of these were randomly selected (approximately 90 samples per wildlife species) and tested with the modified Ziehl Neelsen staining technique (ZN) for Cryptosporidium spp. The prevalence of Cryptosporidium spp. was highest in elephants (25.8% [95% confidence interval: 17.3, 35.9]), compared to buffalo (5.5% [1.8, 12.4]) and impala (4.3% [1.2, 10.5]). C. parvum showed similar patterns, being most prevalent in elephants (4.2% [1.5, 8.8]), compared to buffalo (1.4% [0.2, 5.1]) and impala (1.9% [0.4, 5.3]). 29 samples, including ZN positive and IFA positive samples, were retested using a real time PCR (rtPCR) technique. Of the 28 ZN-positive samples, 14 (50%) were positive with rtPCR and of the 9 IFA-positive samples 6 (67%) were confirmed positive by rtPCR. The prevalence of Cryptosporidium oocysts was significantly higher in both of the two study areas adjacent to the western KNP boundary compared to the area in the centre of the KNP ( OR = 3.2 [1.2, 9.0]; P = 0.024). Our study demonstrates for the first time the presence of Cryptosporidium spp. in wildlife in South Africa. The transmission of this parasite between wildlife, domestic animals and humans is a plausible hypothesis and represents a potential risk for immunodeficient human populations.

The distribution and abundance of native ungulates were measured on commercially managed, semi-arid rangeland in central Kenya over a 3-year period that encompassed severe drought and above-average rainfall. Native ungulate biomass density averaged 5282 kg km )2 over the study and was dominated by elephant (Loxodonta africana), impala (Aepyceros melampus) and dik-dik (Madoqua kirkii). Biomass density of domestic cattle (Bos taurus) averaged 2280 kg km )2 during the study. Responses of native ungulates to severe drought were variable. Impala densities were similar to or greater than densities for similar habitat in protected areas, and varied from 12 to 16 km )2 during and following the drought to 24–29 km )2 following above-average rainfall. Dik-dik densities were also greater than densities reported for protected areas and were surprisingly stable throughout the study despite the wide annual fluctuations in rainfall. Elephant migrated out of the region during drought but were present at high densities (2.9–5.2 km )2 ) during wet seasons, consistent with telemetry studies emphasizing the importance of Acacia bushland habitat on commercial rangelands for the migratory portion of the Laikipia–Samburu elephant population. Results show that substantial densities of native browsing and mixed-feeding ungulates can occur on rangeland managed for commercial beef production and suggest that the capacity for ungulates to move over large spatial scales (>100 km 2 ) and to shift distributions in re

Artificial waterholes are a widely used, yet contested wildlife management practice in semi-arid environments. We evaluated wildlife water provisioning at four artificial waterholes in the southern region of the Kruger National Park. We documented daily waterhole visitation patterns of mammals during the wet and dry seasons using camera-traps. We recorded 26 mammal species at the waterholes, with African elephants (Loxodonta africana) and impalas (Aepyceros melampus) being the most abundant. We used generalized linear mixed models (GLMM) to determine which variables (season, time of day, water quality, and the presence of carnivores or elephants) would affect animal visitation. Waterhole visitation patterns differed according to time of day, but this effect remained relatively constant between seasons. More animals visited waterholes in the dry season compared to the wet season. Carnivore presence negatively affected impala abundance. Elephant presence did not affect impala and white rhinoceros (Ceratotherium simum) visits to waterholes. Water quality also appeared to play a role in determining animal abundance. Based on our results, though obtained from a limited sample size, we suggest some management practices to be considered when deciding which waterholes should be closed down or left open.

Adult impala engage in a form of reciprocal allogrooming distinguished by a high degree of reciprocity and ***lack of influence of dominance or relatedness on partner preference or distribution of grooming between partners. A previous study on reciprocal allogrooming of captive newborn impala lambs in a zoological park found that the allogrooming emerged as early as the first week after birth and was identical in structure and reciprocity to allogrooming in adults. Because these findings of apparently unique allogrooming behavior of newborn impala could have been a reflection of the effects of being born and raised in a small, stable captive herd, it was necessary to investigate reciprocal allogrooming in newborn impala in the wild. The emergence, reciprocity, rate, and partner distribution of reciprocal allogrooming in wild newborn impala were observed at two study sites: a national park in Zimbabwe and a game farm in South Africa. Maternal one-way grooming between mother and newborn emerged as distinct from reciprocal allogrooming and rapidly declined after week 1 postpartum. Reciprocal allogrooming by lambs was first seen between 5 and 8 d postpartum, and as soon as the behavior occurred it was the same basic pattern as seen in adult impala. The reciprocity index for lambs was near 0.5, indicating that lambs delivered as much grooming during an encounter as the partner. Lambs were grooming frequently with non-mother adults and other lambs by week 1 or 2; by week 3 and onward the allogrooming rate of lambs was more than twice that of their mothers, as predicted by the body size principle of the programmed grooming model. The strong predisposition of neonatal impala lambs to deliver reciprocal allogrooming as early as the first or second week postpartum would appear to reflect a genetically acquired adaptation to the threat of tick infestation in their natural habitat.

We investigated herd-sizes and herd-compositions of Impala (Aepyceros melampus) inside a protected area [Lake Mburo National Park (LMNP) in western Uganda] and the unprotected adjacent ranchland [the Ankole Ranching Scheme (ARS)]. Impala experience intense hunting and poaching in the study area, and poaching is especially strong on the ARS. We found evidence for changes in overall group-sizes in both mixed-sex and pure bachelor herds between areas in and outside LMNP. Mixed-sex herds strongly decreased in size outside the National Park, but bachelor herds even slightly increased in size. While the group-composition of mixed-sex herds was very similar in areas in and outside LMNP, bachelor herds comprised more yearlings and subadult males on the ARS. Our study suggests that effects of hunting and other human nuisance may differ between herd types: mixed herds probably decrease in size because females are more strongly hunted. Around LMNP, impala are usually hunted using nets and spears, thereby increasing the hunters’ chance of being injured. Poachers therefore prefer hornless females (and their calves), as it is less dangerous to handle net-caught females than males. As a result, males are less hunted, but increased vigilance and, therefore, reduced aggression among the members of a bachelor herd, may account for the observed increase in herd sizes and changes in group-compositions. Resume Nous avons etudie la taille et la composition des hardes d’impalas (Aepyceros melampus) dans une aire protegee, le Parc National du Lac Mburo (LMNP) dans l’ouest de l’Ouganda, et dans le ranch adjacent non protege, le Ankole Ranching Scheme (ARS). Les impalas subissent une chasse et un braconnage intenses dans la region etudiee et le braconnage est particulierement grave dans l’ARS. Nous avons decouvert des preuves de changement de la taille moyenne des groupes, aussi bien dans les hardes mixtes que dans celles composees uniquement de mâles, entre les aires situees dans et en dehors du LMNP. La taille des hardes mixtes diminuait fortement hors du parc national alors que les hardes composees de mâles augmentaient legerement. Alors que la composition des groupes mixtes etait tres semblable dans et en dehors de l’aire protegee, les groupes de mâles comprenaient plus de jeunes de l’annee et de subadultes dans l’ARS. Notre etude laisse penser que les effets de la chasse et des autres nuisances d’origine humaine pourraient differer selon le type de harde: la taille des hardes mixtes se reduit probablement parce que les femelles sont chassees davantage. Autour du LMNP, les impalas sont d’habitude chasses au moyen de filets et de fleches, ce qui augmente les risques que les chasseurs soient blesses. Les braconniers preferent donc les femelles, sans cornes, et leurs jeunes parce qu’il est plus facile de manipuler des femelles prises dans des filets que des mâles. Par consequent, les mâles sont moins chasses, et une plus grande vigilance et donc une moins forte agression entre les membres d’une harde de mâles peuvent expliquer en partie pourquoi la taille des hardes augmente et la composition des groupes varie.

The meat quality of kudu and impala was compared. Live weight and carcass weight differed between species, genders and age groups. Impala had the highest dressing percentage while kudu had the highest live weight and carcass weight. Kudu had the lowest fat content while female animals had a higher fat and myoglobin content than males. Sub-adults had a higher ash content than adults. Species, gender and age had no effect of pH, drip loss, cooking loss or tenderness although kudu had higher L∗, a∗, b∗ and chroma values than impala. Impala sub-adults had significantly higher insoluble collagen, soluble collagen, total collagen and hydroxyproline content than kudu sub-adults. Kudu had the highest potassium levels while impala had the highest phosphorus levels. Potassium, sodium, iron and copper levels also differed between species.

Fecal glucocorticoid metabolite (FGM) assays are a popular means of monitoring adrenocortical activity (i.e., physiological stress response) in wildlife. Species-specific differences in glucocorticoid metabolism and excretion require assay validation, including both laboratory and biological components, before assay use in new species. We validated a commercially available radioimmunoassay (MP 125I corticosterone RIA kit [MP Biomedicals, Solon, OH]) for measuring FGMs of several South African herbivores, including giraffe (Giraffa camelopardalis), impala (Aepyceros melampus), nyala (Tragelaphus buxtoni), kudu (Tragelaphus strepsiceros), wildebeest (Connochaetes taurinus), and zebra (Equus burchelli). These herbivores are important in South African parks and reserves for ecotourism and as a prey base for predators and serve an integral role in ecosystem processes. Standard biochemical validations (e.g., recovery of exogenous corticosterone, intra- and interassay variation, and parallelism) demonst...

Grouping patterns within the genus Tragelaphus suggest that species inhabiting open areas tend to live in larger groups, while species preferring dense habitats live solitarily or in small family groups. We asked if similar variation would be concealed in the within-species variation of bushbuck (Tragelaphus scriptus). Recent molecular phylogeographic analyses revealed several locally adapted forms of bushbuck in different ecoregions on the African continent. We compared group sizes of south-eastern bushbuck (Tragelaphus sylvaticus) among six different populations (“ecotypes”). To date, most data on the social organization of bushbuck have been collected from only one population in Queen Elizabeth National Park (QENP) in Uganda. This particular population, however, inhabits an unusual—comparatively open—habitat type, while bushbuck otherwise inhabit dense habitats, leaving doubt whether data collected in QENP are representative of the entire species. We, therefore, compared grouping patterns between ecotypes inhabiting rather open habitats (e.g., dianae and haywoodi) and ecotypes occupying rather dense habitats (e.g., massaicus and ornatus). In bachelor groups and in all-female (spinster) groups, single sightings were the most frequent “group type” in all populations examined. We detected no significant difference among ecotypes in relative frequencies of group size categories in the case of bachelor groups. Spinster group sizes were slightly (albeit significantly) smaller in QENP than in all other areas. Moreover, a comparison of two areas inside (low human pursuit) and outside Lake Mburo National Park (high hunting pressure) in Uganda revealed no significant difference in grouping patterns in response to human pursuit (as reported for impala [Aepyceros melampus] inhabiting the same area). Altogether, our results suggest that group sizes in bushbuck are not dependent on the habitat type they inhabit; neither does human nuisance have an impact on grouping patterns. Hence, an “almost solitary” lifestyle appears to be a characteristic of the entire taxon.

The phylogenetic relationships of Hunter's antelope or hirola Beatragus hunteri (Artiodactyla: Alcelaphini), one of the most seriously threatened antelopes in Africa, have been the subject of controversial discussion. A total of 801 base pairs of the mitochondrial cytochrome b gene were determined from five alcelaphine species and from two nonalcelaphine bovids. Phylogenetic analysis using parsimony, maximum likelihood, and distance methods identified a single best-supported hypothesis of evolutionary relationships within the Alcelaphini: (i) monophyly of the tribe, (ii) most basal position of the blue wildebeest, (iii) sister-grouping of the Lichtenstein's and Coke's hartebeests, (iv) phylogenetic distinctiveness of the hirola from the topi and the hartebeests. We deduce that the alcelaphine cytochrome b sequences began to diverge from a common mitochondrial ancestor about 5.5 million years ago. In addition, we provide molecular evidence that the impala Aepyceros melampus is not closely related to Alcelaphini.

In South Africa, night cropping from a vehicle Is commercially used to crop game. Conventional hunting employs the principles of fair chase and usually consists of hunting on foot during the day. The purpose of this study was to compare the meat quality of the Impala (Aepyceros melampus) shot utilizing these two methods. No significant differences In pH45 or pHu were found between the two methods. An exponential decay model (y = a + b-ct) was fitted to the pH data and conventionally hunted animals showed significantly higher rates of pH decline (c = -0.385 ± 0.022 units per hour) than night-cropped animals (c = -0.184 ± 0.019 units per hour) - a phenomenon that may be linked to the ante-mortem stress experienced by the animals, and the cooling rate of the carcasses. Impala conventionally hunted also had significantly higher constants for the pH exponential model (a = 5.424 ± 0.039; b = 1.405 ± 0.034) than the night-cropped Impala (a = 5.295 ± 0.033; b = 1.556 ± 0.029). No significant differences were foun...

Summary 1 Top-down regulation of ecosystems by large herbivores is a topic of active debate between scientists and managers, and a prime example is the interaction between elephants Loxodonta africana and trees in African savannas. A common assumption among wildlife managers is that a local reduction in elephant numbers will ultimately allow woodland to self-restore to a desired former state. Such regeneration is, however, dependent on the survival of seedlings of impacted tree species. We conducted a field experiment to investigate seedling predation in the elephant-transformed Chobe riparian woodland of northern Botswana. 2 We planted seedling gardens in (i) complete exclosures that excluded all herbivores except small rodents and invertebrates, (ii) semi-permeable exclosures that excluded ungulates but included primates, lagomorphs, all rodents, gallinaceous birds, etc, and (iii) completely open plots. Seedlings were of two tree species decreasing in the area (Faidherbia albida and Garcinia livingstonei) and two that are increasing (Combretum mossambicense and Croton megalobotrys). 3 After 9 months, seedling survival ranged from >75% for all species in the complete exclosure to

A case-control study was performed in the Kruger National Park (KNP), South Africa, to find out whether impala ( Aepyceros melampus ) were more likely to harbor tetracycline-resistant Escherichia coli (TREC) in their feces when they drank from rivers that contained these bacteria than when they drank from rivers that were uncontaminated with TREC. The following five perennial rivers were selected: the Crocodile, the Letaba, the Olifants, the Sabie, and the Sand. Samples of river water ( n = 33) and feces ( n = 209), collected at 11 different sites, were cultured for E. coli. The resulting colonies were screened for tetracycline resistance by use of the Lederberg replica plating method (breakpoint, 4 mg/liter). A resistant and/or a susceptible isolate was then selected from each sample and subjected to the CLSI MIC broth microdilution test for tetracyclines. Among the 21 water specimens contaminated by E. coli , 19.05% ( n = 4) were found to be resistant by the MIC method (breakpoint, ≥8 mg/liter). This led to the Crocodile, Olifants, and Letaba rivers being classified as TREC positive. Among the 209 impala feces sampled, 191 were positive for the presence of E. coli (91.38%). Within these ( n = 191), 9.95% ( n = 19) of the isolates were shown to be TREC by the MIC method. It was found that 1.11% ( n = 1) of the E. coli isolates cultured from the feces of the control group ( n = 90) were TREC, in comparison with 17.82% ( n = 18) of those in feces from the exposed group ( n = 101). The calculation of the odds ratio showed that impala drinking from TREC-contaminated rivers were 19.3 (2.63 to 141.69) times more likely to be infected with TREC than were unexposed impala. This is a significant finding, indicating that surface water could be a possible source of antimicrobial resistance in naïve animal populations and that impala could act as sentinels for antimicrobial resistance.

This study compares two methods of estimating the density of three ungulate species: Kirk’s dik-dik, impala and common zebra, in a dry savannah ecosystem. Fixed strip width and distance sampling involving direct animal counts were used in parallel, and tested for bias and precision in two habitats. Distance sampling was the method that achieved a better balance between accuracy and precision. The differences in sightability of ungulates, according to body size, colour and habitat characteristics, are taken into account by the distance sampling method, but not by the strip method, which produced, what we suspect are, underestimates of animal density. Resume Cette etude compare deux methodes pour estimer la densite de trois especes d’ongules : le dik-dik de Kirk, l’impala et le zebre de Burchell, dans un ecosysteme de savane seche. On a utilise en parallele l’echantillonnage par largeur de bande fixe et celui a distance perpendiculaire, impliquant le comptage direct des animaux, et nous avons teste les biais qu’ils induisent et leur precision dans deux habitats. L’echantillonnage a distance perpendiculaire fut la methode qui a obtenu le meilleur equilibre entre exactitude et precision. Les differences de visibilite des ongules, selon la taille corporelle, la couleur et les caracteristiques de l’habitat, sont prises en compte par la methode a distance mais pas par la methode par bande qui entraine, nous le suspectons, des sous-estimations de la densite animale.