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Africa supports Earth's richest assemblage of large predators, which coexist despite a high degree of dietary overlap. This study used reviews of the prey preferences of African wild dog Lycaon pictus, cheetah Acinonyx jubatus, leopard Panthera pardus, lion P. leo, and spotted hyaena Crocuta crocuta to investigate the degree of dietary overlap and dietary niche breadth amongst the guild. Wild dogs and cheetahs exhibited the greatest dietary overlap and smallest dietary niche breadth, while lions exhibited the least dietary overlap and, with leopards, had the broadest dietary niche breadth. Increased extinction risk within the guild was related to lower dietary niche breadth. The behavioural and morphological specializations of the two most threatened predators (wild dogs and cheetahs) limit the prey available to them, and increases the potential for dietary competition. Conversely, the large body mass and group hunting strategy of lions and the predatory flexibility of leopards and spotted hyaenas minimizes the effects of dietary overlap, assuring a more secure status. This study intimates reasons why cheetahs and African wild dogs are naturally less common than lions, leopards and spotted hyaenas in unmodified landscapes. The methods used can be applied to all adequately studied faunal guilds and could highlight previously undetected competitors.
Parental care of unrelated young in species able to recognize their own offspring is called adoption. Here, we establish adoption as a novel conservation tool for endangered African wild dogs (Lycaon pictus) to augment the size of existing packs in situ and to enhance gene flow among isolated populations. Three cases of facilitated adoption of orphaned pups by unrelated free-ranging wild dogs are reported. All pups were successfully integrated into an adoptive pack. Besides individual fitness benefits accruing from larger pack size, we propose that wild dogs may also adopt pups due to benefits relating to the future reproductive value of unrelated individuals. This study will hopefully stimulate further research on the adaptive value and conservation implications of adoption in other endangered species.
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.
Haemotropic Mycoplasma species are pathogens that can cause haemolytic anaemia in susceptible mammalian species worldwide. The cause of haemolysis is due to membrane damage through stimulation of IgM cold agglutinins production, which induces autoimmune haemolysis of infected erythrocytes. A study was conducted to establish the prevalence of Mycoplasma haemofelis, ‘Candidatus Mycoplasma haemominutum’ and ‘Candidatus M. turicensis’in ticks and the diversity of tick species that are possible vectors of the pathogens that can transmit the infection to wildlife in Ngorongoro Crater. Three real-time PCR assays were used for the analysis of DNA pools (n = 507) derived from 11 tick species. Mycoplasma haemofelis and ‘Candidatus M. haemominutum’ were detected in Rhipicephalus sanguineus. On average 19.7% and 12.9% of R. sanguineus were PCR-positive for M. haemofelis and ‘Candidatus M. haemominutum’, respectively. This tick species therefore represent an important reservoir for feline haemotropic Mycoplasma species in the crater. These organisms with their known pathological effects are probably one of the factors potentially exacerbating the severity of infection during the disease outbreak in wildlife and can have undesirable outcome to wild cats like lions when under nutritional stress or in case of concurrent infection.
Conflict between farmers and large carnivores exists on Namibian rangelands and farmers continue to remove large carnivores indiscriminately. An appreciation for the economic and ecological roles of large carnivores cannot be expected to improve if the correct information is lacking and misconceptions persist. Conservancies are growing in importance in the conservation of Namibia's wildlife outside protected areas and may be important structures for information dissemination and improving wildlife management. This study investigated the role that farming enterprise (livestock and mixed livestock/game farming) and conservancy membership played in human–large carnivore conflict on commercial farms in Namibia. Our study found that the attitude towards large carnivores was similar between farming enterprises but that conservancy members within each enterprise were more likely to be tolerant of large carnivores and to use livestock management options to reduce conflict, than non-conservancy members. Cause for concern however, was the high proportion of all farmers, including those belonging to conservancies, which reported removing large carnivores from their farms. This aspect is reflected in the poor content of conservancy management plans with regard to large carnivore management and human–large carnivore conflict mitigation measures. The failure to incorporate guidelines pertaining to human–carnivore conflict management into conservancy management plans reflects the lack of a structured approach to solving this conflict on farmlands.
Like many pinniped species, southern elephant seals (Mirounga leonina) are conducive to long-term population studies using mark–recapture techniques. The twenty-four year longitudinal dataset at sub-Antarctic Marion Island has already provided much insight into elephant seal population dynamics. However, a limitation of the present dataset is that mother/pup relatedness cannot be examined because pups are only tagged after their tagged mothers have abandoned them. We test the usefulness of two different temporary marking techniques (tagging and ‘strapping’), and four different marker types over two consecutive breeding seasons for use on pups with attending marked mothers. We show that strapping is an ineffective way to mark unweaned southern elephant seals. By comparison, ‘Supersmall®’ Dalton plastic tags allow quick, effective and easy marking of large numbers of pups with known mothers, without excessive marker loss.
In gregarious species, rates of foraging behaviour are often positively related to group size while there is simultaneously a negative relation between group size and vigilance. Although the mechanisms underlying these behavioural patterns are still incompletely understood, decreased predation risk or increased foraging competition in larger groups have been put forward as two possible explanations. Since most empirical tests of these two hypotheses have used manipulative experiments, they have mainly been limited to small-bodied species or to animals in captivity. Here we suggest a time-budget model to test for the causal effects of predation risk and foraging competition that does not necessitate manipulative approaches. We used this method on two species of gregarious antelope, blesbok (Damaliscus pygargus phillipsi) and impala (Aepyceros melampus). We suggest that increased foraging competition in large groups drives the negative relationship between vigilance and group size in these species. This study shows that observational data can be used to test explicit hypotheses on species that are logistically unsuitable for manipulative experiments, and also render support for hypotheses suggesting that factors unrelated to predation risk are involved in shaping the differences in vigilance rates over different group sizes in gregarious species.
There are local populations of African elephants (Loxodonta africana) which have increased to levels where they are implicated in altering vegetation types. The local reduction of elephant numbers for wildlife management objectives can involve contraception, killing excess animals, or translocation to alternative habitats. The effects these management decisions can have on the physiological stress response of free-ranging African savanna elephants are still not fully understood. We examined the effect of translocation on faecal glucocorticoid metabolite levels of an African elephant family group,which was translocated within the Kruger National Park, South Africa. We found that translocation resulted in a significant increase in faecal glucocorticoid metabolite levels (up to 646 ng/g wet weight) compared to (1) pre-translocation levels in this group, (2) post-translocation levels in this group, and (3) levels measured in undisturbed ‘control’ groups in the area. However, the faecal glucocorticoid metabolite levels had returned to <100 ng/g by the time the translocated animals had navigated their way back to their previous home range, covering 300 km in 23 days.
This study analysed road accident data for a five-year period on a route between Uitenhage and Graaff-Reinet in the Eastern Cape (South Africa) to investigate the temporal patterns of animal-related accidents (ARAs). Although a large number of ARAs was recorded during the high-traffic holiday season, a distinct period of relatively high ARA rates was identified from April to July. These months coincide with the rutting and hunting seasons of greater kudu (Tragelaphus strepsiceros) when movement is more pronounced. The observed daily danger times for ARAs are from dusk to around midnight and early mornings until dawn. Weekends, with increased motor vehicle traffic, are also hazardous times. These results should be used by traffic authorities and regional traffic managers to help initiate mitigating procedures and launch public awareness programmes to inform motorists of the most accident-prone times of the day, days of the week and seasons of the year for animal-related motor vehicle accidents.
Gastrointestinal tracts from 48 helmeted guineafowl (Numida meleagris), five Swainson's spurfowl (Pternistis swainsonii) and a single Orange River francolin (Scleroptila levaillantoides) were examined for helminth parasites. Twelve species of helminths were found in helmeted guineafowl, comprising six nematodes, five cestodes and a single acanthocephalan. Six species of nematodes were recovered from Swainson's spurfowl and a single nematode was recovered from the Orange River francolin. First-year guineafowl had more than twice the intensity of infection than did adult guineafowl, particularly regarding the acanthocephalan Mediorhynchus gallinarum, the caecal nematodes Subulura dentigera and S. suctoria, and the cestodes Octopetalum numida, Hymenolepis cantaniana and Numidella numida. Female guineafowl had significantly higher intensities of infection than males, especially concerning M. gallinarum, S. dentigera and N. numida and the nematode Gongylonema congolense. The recovery of the cestode Retinometra sp. from helmeted guineafowl constitutes a new host-parasite record.
Maputaland is a centre of plant endemism, within the Maputaland–Pondoland–Albany hotspot of biodiversity shared by Mozambique and South Africa. The Sand Forest vegetation is the most valuable vegetation type in this region due to the endemics it harbours, but it is currently under threat from growing animal population densities within conserved areas and from a growing human population outside. To improve our understanding of Sand Forest dynamics the present study investigated the woody plant assemblages in Tembe Elephant Park. A total of 59 plots were sampled and analysed using classification and ordination methods. The results indicate that Sand Forest in Tembe is a complex assemblage of at least three floristically and structurally distinct woody communities. An ordination of the combined results from the present study together with two other studies could link the floristics and structure of the Sand Forest to the level of disturbance by herbivores and humans. Large herbivores induce both structural and floristic changes in the Sand Forest of Tembe Elephant Park and a lack of disturbance in the nearby Tshanini Community Conservation Area leads to a state of equilibrium. The results therefore suggest that Sand Forest dynamics and complexity may be strongly linked to small- to medium-scale animal disturbance.
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.
The aim of this study was to investigate transmitter attachment and longevity on Nile crocodiles (Crocodylus niloticus) in the Flag Boshielo Dam, Mpumalanga, South Africa. From August 2002, 15 adult Nile crocodiles were captured over a 19-month period in the Flag Boshielo Dam. Conventional VHF transmitters were fitted to the tails of eight male and five female Nile crocodiles, while a GPS/GSM transmitter was fitted dorsally to the neck of one male and one female Nile crocodile. There was no significant difference in the total lengths of male and female Nile crocodiles captured for transmitter fitment. Overall, 40% of the transmitters failed, while an equal number was broken off. Neither sex, nor total length of the Nile crocodiles predicted longevity of transmitters from time of fitment to time of failure or destruction and loss. In future, the tails of crocodiles should be avoided when attaching transmitters, as conspecifics seem to target this area during agonistic behaviour. Moreover, it is essential that transmitters and their attachment configurations be tested on the target species before a study commences. Lastly, we urge researchers to routinely provide information on the performance of transmitters and their fitment configurations.
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