Jan F. Kamler

Diet, prey selection, and predation impact of black-backed jackals in South Africa.

Abstract To investigate the role of black-backed jackals (Canis mesomelas) as predators, we studied diet, prey selection, and predation impact of jackals on 2 game ranches in South Africa that differed in ungulate diversity and biomass. Results showed that large (>15 kg) ungulate species dominated jackal diets throughout the year on both the less diverse (range of ingested biomass across seasons u200a=u200a 39–78%) and more diverse (26–69%) game ranch. Other important food items included medium-sized mammals (1–3 kg; 1–26%) and fruit (2–69%), whereas small mammals comprised 3–11% of ingested biomass across seasons on both sites. Jackals were not random in consumption of ungulates, and consumption patterns suggested jackals actively hunted certain species rather than consumed them as carrion. During ungulate birthing periods, jackals consumed almost exclusively those ungulate species that were hiders (i.e., fawns were hidden in tall vegetation away from herd) regardless of ungulate densities, suggesting that primarily fawns were preyed upon. Among hiders, there was a negative relationship (P u200a=u200a 0.01) between body size and percent of population consumed by jackals, indicating smaller species were more susceptible than larger species to jackal predation. Consequently, springbok (Antidorcas marsupialis) were always selected over other ungulate species on both sites, and this species was the most impacted by jackal predation. In contrast, ungulate species that were followers (i.e., fawns immediately followed mothers within protection of the herd) were scarcely or not at all consumed by jackals, regardless of body size or density. Medium-sized mammals were selectively consumed over ungulates, and there was a negative relationship (P < 0.01) between consumption of berries and ungulates, indicating alternative food resources influenced consumption of ungulates on our study sites. Our results will help wildlife managers in Africa identify ungulate species susceptible to jackal predation, and can be used to develop management strategies for reducing jackal predation in areas where it is problematic.

Lethal and sublethal effects of black-backed jackals on cape foxes and bat-eared foxes

Abstract Little is known about the sublethal effects of mesocarnivores on small carnivores, which can have important implications regarding the ecology and behavior of the latter. We investigated the ecology of cape foxes (Vulpes chama) and bat-eared foxes (Otocyon megalotis) in the absence of black-backed jackals (Canis mesomelas), a dominant mesocarnivore and predator of both fox species. Results were compared with a concurrent study that investigated the ecology of both fox species in the presence of jackals, at a site <5 km away. In the absence of jackals, densities of cape foxes increased 64% despite similar food and habitat resources between sites, indicating that jackals suppressed cape fox populations. In contrast, jackals did not suppress populations of bat-eared foxes. For both fox species, the absence of jackals resulted in smaller home-range sizes and nonselective use of habitats for den sites, indicating that jackals had sublethal effects on the ecology and behavior of both fox species. Additionally, in the absence of jackals, cape foxes were marginally more active during daytime, whereas bat-eared foxes exhibited smaller group sizes. The 2 fox species became more segregated in the absence of jackals, indicating that jackals also had sublethal effects on the interspecific relationships of fox species. Our results showed that the effects of a mesocarnivore can extend well beyond population suppression of small carnivores, although sublethal effects varied in intensity and often were species specific. Sublethal effects on small carnivores can occur even if population suppression by a mesocarnivore is not occurring.

The diet, prey selection, and activity of dholes (Cuon alpinus) in northern Laos

Abstract Although Southeast Asia is one of the last strongholds of endangered dholes (Cuon alpinus), or Asiatic wild dogs, little is known about dhole ecology in this region. We used scat collections, prey surveys, and camera-trap data to determine the diet, prey selection, and activity of dholes in a national protected area in northern Laos. Results showed that dhole diets were dominated by ungulates (87% of biomass consumed), with additional prey including other carnivores (6%) and rodents < 1 kg (6%). Concerning individual prey species, only muntjac (Muntiacus, 45%) and sambar (Rusa unicolor, 33%) contributed >7% of biomass consumed. Dholes were not random in their consumption of ungulates, because muntjac (20–28 kg) and sambar (185 kg) were selectively consumed over medium-sized (75- to 85-kg) ungulates. Dholes were almost exclusively diurnal, and their activity pattern was significantly different (all P < 0.003) from that of all ungulate species except wild pigs (Sus scrofa). Overall, prey selection by dholes appeared to be more influenced by social behavior and terrain use of ungulates, rather than by body size or activity of ungulates. In tropical forests of northern Laos, dholes focused predation on relatively few species during diurnal hours, suggesting the management of muntjac and sambar may be important for conserving dhole populations in the region.

To kill, stay or flee: the effects of lions and landscape factors on habitat and kill site selection of cheetahs in South Africa.

Understanding how animals utilize available space is important for their conservation, as it provides insight into the ecological needs of the species, including those related to habitat, prey and inter and intraspecific interactions. We used 28 months of radio telemetry data and information from 200 kill locations to assess habitat selection at the 3rd order (selection of habitats within home ranges) and 4th order (selection of kill sites within the habitats used) of a reintroduced population of cheetahs Acinonyx jubatus in Phinda Private Game Reserve, South Africa. Along with landscape characteristics, we investigated if lion Panthera leo presence affected habitat selection of cheetahs. Our results indicated that cheetah habitat selection was driven by a trade-off between resource acquisition and lion avoidance, and the balance of this trade-off varied with scale: more open habitats with high prey densities were positively selected within home ranges, whereas more closed habitats with low prey densities were positively selected for kill sites. We also showed that habitat selection, feeding ecology, and avoidance of lions differed depending on the sex and reproductive status of cheetahs. The results highlight the importance of scale when investigating a species’ habitat selection. We conclude that the adaptability of cheetahs, together with the habitat heterogeneity found within Phinda, explained their success in this small fenced reserve. The results provide information for the conservation and management of this threatened species, especially with regards to reintroduction efforts in South Africa.

Distance Sampling for Estimating Springhare, Cape Hare and Steenbok Densities in South Africa

Distance sampling using line transects has become a well-known method for estimating densities of both large and small mammals in relatively open habitats, although it has not yet been reported for smaller mammals (<10 kg) in southern Africa. In 2007 and 2008 we used distance sampling to estimate numbers of springhares (Pedetes capensis), Cape hares (Lepus capensis) and steenbok (Raphicerus campestris) on farms near Kimberley, South Africa. Surveys for springhares and Cape hares were conducted on Benfontein Game Farm, whereas surveys for steenbok occurred on nearby small-livestock farms. We derived density estimates with relatively low 95% confidence intervals and coefficients of variation for all three species, with only moderate time spent in the field by researchers. Our results suggest distance sampling using line transects is a very useful and efficient technique for estimating densities of springhare, Cape hare and steenbok populations in relatively open and homogeneous habitats.

Genetic structure, spatial organization, and dispersal in two populations of bat‐eared foxes

We incorporated radio-telemetry data with genetic analysis of bat-eared foxes (Otocyon megalotis) from individuals in 32 different groups to examine relatedness and spatial organization in two populations in South Africa that differed in density, home-range sizes, and group sizes. Kin clustering occurred only for female dyads in the high-density population. Relatedness was negatively correlated with distance only for female dyads in the high-density population, and for male and mixed-sex dyads in the low-density population. Home-range overlap of neighboring female dyads was significantly greater in the high compared to low-density population, whereas overlap within other dyads was similar between populations. Amount of home-range overlap between neighbors was positively correlated with genetic relatedness for all dyad-site combinations, except for female and male dyads in the low-density population. Foxes from all age and sex classes dispersed, although females (mostly adults) dispersed farther than males. Yearlings dispersed later in the high-density population, and overall exhibited a male-biased dispersal pattern. Our results indicated that genetic structure within populations of bat-eared foxes was sex-biased, and was interrelated to density and group sizes, as well as sex-biases in philopatry and dispersal distances. We conclude that a combination of male-biased dispersal rates, adult dispersals, and sex-biased dispersal distances likely helped to facilitate inbreeding avoidance in this evolutionarily unique species of Canidae.

The current distribution and status of leopards Panthera pardus in China

The leopard Panthera pardus, categorized globally as Near Threatened on the IUCN Red List, has the widest distribution of any wild felid species, although in Asia it has declined dramatically and five subspecies are Endangered or Critically Endangered. In China at least three subspecies have been reported to occur throughout much of the country, and in 1998 the population was estimated to be 1,000. However, recent studies have indicated that leopards have disappeared from large areas, probably as a result of habitat loss, a low prey base and poaching, indicating this species may not be as common in China as previously believed. To examine this we reviewed recent literature and interviewed specialists to determine the current status and distribution of the leopard in China. Our findings indicate that the species has declined dramatically, with confirmation of presence at only 44 sites in 11 provinces, despite extensive surveys. Current populations are small and fragmented, and occur mainly in isolated nature reserves. We estimate a total population of only 174–348 P. pardus japonensis (the north Chinese leopard), which is endemic to China, and < 30 individuals for each of the other subspecies whose distributions extend beyond China. We recommend that a separate IUCN assessment be made for P. pardus japonensis, and that this subspecies be categorized as Critically Endangered. Our findings are the first reliable estimates of the current distribution and status of the leopard in China, and provide valuable information that will help guide conservation efforts.

Efficiency and safety of Soft Catch traps for capturing black-backed jackals and excluding non-target species

Abstract During a broader study of canid ecology in South Africa in 2005 and 2006, we evaluated the efficiency and safety of Soft Catch foothold traps for both capturing black-backed jackals (Canis mesomelas) and excluding non-target species. With the pan tension set at 1.75 kg, the capture efficiency was 88% for black-backed jackals (15 captured/17 visits), with no (80%) or very minor (20%) visible injuries to captured jackals. The exclusion efficiency for non-target species was 93% (42 not captured/45 visits). Two aardwolves (Proteles cristatus) and one bat-eared fox (Otocyon megalotis) were captured and released with no injuries, while one other aardwolf, 18 other foxes and 24 individuals from numerous smaller species were excluded. Our results indicate that black-backed jackals can be safely and efficiently captured in Soft Catch traps while excluding most non-target species, if traps are checked regularly and pan tensions are set at the appropriate weight.

New records of servals Leptailurus serval in central South Africa

Abstract Servals are restricted to eastern South Africa, apparently due to favourable habitat types in this region. Despite their recorded absence from central South Africa, we provide more than 20 new records of servals from the Free State, eastern Northern Cape, and southern North West from over the past two decades. Most records are close to rivers or dams, suggesting servals use waterways as corridors to penetrate otherwise unsuitable habitat in drier areas. These new records provide evidence of an apparent re-colonization of the eastern Free State, and of recent long-distance dispersers and/or a range expansion into suitable areas in the western Free State and eastern Northern Cape.

Cattle Egret and Common Ostrich associations in South Africa

) associations are one of the most well known of allbird and mammal associations (Heatwole 1965). CattleEgrets benefit from cattle (and presumably other largemammals) by feeding on invertebrates and other smallorganisms disturbed by the foraging Cattle (Dinsmore1973). Several studies have shown that Cattle Egretsgreatly increase their foraging efficiency while decreasingtheir energy expenditure when feeding in association withcattle, as compared to feeding alone (Heatwole 1965,Dinsmore 1973, Grubb 1976). The diets of Cattle Egretsshow considerable diversity, and primarily consist of inver-tebrates such as grasshoppers, beetles, flies, caterpillars,and earthworms (Siegfried 1971, Hockey