Inbreeding Avoidance Influences the Viability of Reintroduced Populations of African Wild Dogs (Lycaon pictus)

The conservation of many fragmented and small populations of endangered African wild dogs (Lycaon pictus) relies on understanding the natural processes affecting genetic diversity, demographics, and future viability. We used extensive behavioural, life-history, and genetic data from reintroduced African wild dogs in South Africa to (1) test for inbreeding avoidance via mate selection and (2) model the potential consequences of avoidance on population persistence. Results suggested that wild dogs avoided mating with kin. Inbreeding was rare in natal packs, after reproductive vacancies, and between sibling cohorts (observed on 0.8%, 12.5%, and 3.8% of occasions, respectively). Only one of the six (16.7%) breeding pairs confirmed as third-order (or closer) kin consisted of animals that were familiar with each other, while no other paired individuals had any prior association. Computer-simulated populations allowed to experience inbreeding had only a 1.6% probability of extinction within 100 years, whereas all populations avoiding incestuous matings became extinct due to the absence of unrelated mates. Populations that avoided mating with first-order relatives became extinct after 63 years compared with persistence of 37 and 19 years for those also prevented from second-order and third-order matings, respectively. Although stronger inbreeding avoidance maintains significantly more genetic variation, our results demonstrate the potentially severe demographic impacts of reduced numbers of suitable mates on the future viability of small, isolated wild dog populations. The rapid rate of population decline suggests that extinction may occur before inbreeding depression is observed

Space use of African wild dogs in relation to other large carnivores

Interaction among species through competition is a principle process structuring ecological communities, affecting behavior, distribution, and ultimately the population dynamics of species. High competition among large African carnivores, associated with extensive diet overlap, manifests in interactions between subordinate African wild dogs (Lycaon pictus) and dominant lions (Panthera leo) and spotted hyenas (Crocuta crocuta). Using locations of large carnivores in Hluhluwe-iMfolozi Park, South Africa, we found different responses from wild dogs to their two main competitors. Wild dogs avoided lions, particularly during denning, through a combination of spatial and temporal avoidance. However, wild dogs did not exhibit spatial or temporal avoidance of spotted hyenas, likely because wild dog pack sizes were large enough to adequately defend their kills. Understanding that larger carnivores affect the movements and space use of other carnivores is important for managing current small and fragmented carnivore populations, especially as reintroductions and translocations are essential tools used for the survival of endangered species, as with African wild dogs.The Smithsonian Institution Undersecretary for Science Endowment Funds, the American Zoo and Aquarium Association Conservation Endowment Fund, and Humboldt State University Sponsored Program Foundation (MSG); University of Pretoria, The Green Trust (WWFSA), and Bateleurs and Wildlife Conservation Trust (KZN) (MS); NRF, NSF, University of KwaZulu-Natal, Walt Disney Foundation and MGM, Wild about Cats, and Hluhluwe Tourism Association (RS); and THRIP (N. Ferguson) and Grand Hotel grants (C. Packer).http://www.plosone.orgam201

The curse of observer experience: Error in noninvasive genetic sampling.

Noninvasive genetic sampling (NGS) is commonly used to study elusive or rare species where direct observation or capture is difficult. Little attention has been paid to the potential effects of observer bias while collecting noninvasive genetic samples in the field, however. Over a period of 7 years, we examined whether different observers (n = 58) and observer experience influenced detection, amplification rates, and correct species identification of 4,836 gray wolf (Canis lupus) fecal samples collected in Idaho and Yellowstone National Park, USA and southwestern Alberta, Canada (2008-2014). We compared new observers (n = 33) to experienced observers (n = 25) and hypothesized experience level would increase the overall success of using NGS techniques in the wild. In contrast to our hypothesis, we found that new individuals were better than experienced observers at detecting and collecting wolf scats and correctly identifying wolf scats from other sympatric carnivores present in the study areas. While adequate training of new observers is crucial for the successful use of NGS techniques, attention should also be directed to experienced observers. Observer experience could be a curse because of their potential effects on NGS data quality arising from fatigue, boredom or other factors. The ultimate benefit of an observer to a project is a combination of factors (i.e., field savvy, local knowledge), but project investigators should be aware of the potential negative effects of experience on NGS sampling

Heterogeneity in the density of spotted hyaenas in Hluhluwe-iMfolozi Park, South Africa

Animal population sizes and trends, as well as their distributions, are essential information to the understanding and conservation of ecosystems. During this study in Hluhluwe-iMfolozi Park, South Africa, a spotted hyaena Crocuta crocuta Erxleben, 1777 (Hyaenidae) population was surveyed by attracting individuals with pre-recorded sounds. The hyaena population (excluding cubs) is substantially larger (321 individuals) than the previous estimate of 200 and this population is the second largest protected population in South Africa. Average hyaena density, at 0.357 individuals/km2, was relatively high compared to other southern African conservation areas, and range from 0 to 1.25 individuals/km2 across sampling stations. For short periods, spatial heterogeneity in density was marked at small and large spatial scales, but decreased when averaged over a longer period. This heterogeneity may be important in promoting the coexistence of other large and mobile carnivores in Hluhluwe-iMfolozi Park by creating potential dynamic competition refugia in space and time. Furthermore, heterogeneity of hyaena density at smaller scales should influence studies investigating the avoidance of hyaenas by competitively inferior carnivores.The Green Trust (WWF-SA), The Wildlands Conservation Trust, The Endangered Wildlife Trust, National Research Foundation, Smithsonian Institution, Sichel Family Endowment, Friends of the National Zoo, and the University of KwaZulu-Natal, Centre for Invasion Biology

Dynamics of a small re-introduced population of wild dogs over 25 years: Allee effects and the implications of sociality for endangered species’ recovery

We analysed 25 years (1980–2004) of demographic data on a small re-introduced population of endangered African wild dogs (Lycaon pictus) in Hluhluwe-iMfolozi Park (HiP), South Africa, to describe population and pack dynamics. As small populations of cooperative breeders may be particularly prone to Allee effects, this extensive data set was used to test the prediction that, if Allee effects occur, aspects of reproductive success, individual survival and population growth should increase with pack and population size. The results suggest that behavioural aspects of wild dogs rather than ecological factors (i.e. competitors, prey and rainfall) primarily have been limiting the HiP wild dog population, particularly a low probability of finding suitable mates upon dispersal at low pack number (i.e. a mate-finding Allee effect). Wild dogs in HiP were not subject to component Allee effects at the pack level, most likely due to low interspecific competition and high prey availability. This suggests that aspects of the environment can mediate the strength of Allee effects. There was also no demographic Allee effect in the HiP wild dog population, as the population growth rate was significantly negatively related to population size, despite no apparent ecological resource limitation. Such negative density dependence at low numbers indicates that behavioural studies of the causal mechanisms potentially generating Allee effects in small populations can provide a key to understanding their dynamics. This study demonstrates how aspects of a species’ social behaviour can influence the vulnerability of small populations to extinction and illustrates the profound implications of sociality for endangered species’ recovery.The Green Trust (WWF–South Africa), The Endangered Wildlife Trust, Smithsonian National Zoological Park, Shirley Sichel and Abbott Endowment Funds, Friends of the National Zoo, Smithsonian Institution Office of the Undersecretary for Science), British Airways, Third World Academy of Science, The Wild Dog Foundation, The Sally Club, The Wildlands Conservation Trust, DST–NRF Centre of Excellence for Invasion Biology, Ezemvelo KZN Wildlife, National Research Foundation and the University of KwaZulu-Natal

Reproductive sharing and proximate factors mediating cooperative breeding in the African wild dog (Lycaon pictus)

Although dominant African wild dogs (Lycaon pictus) are generally believed to be the sole breeders within a pack, earlier behavioral and endocrine data suggest that reproduction could be shared with subordinates. We performed an extensive behavioral, demographic, and genetic evaluation of a wild dog population in South Africa to examine the level of such sharing and the proximate mechanisms influencing reproductive contributions of each sex. While a majority of pups were born to dominants because of a lack of subordinate potential breeders, we discovered a substantial portion of reproductive sharing between dominants and subordinates. Compared with alpha females that mated annually, subordinate beta females bred in 54.5% of years whereas thetas never bred. The three topranking males all sired pups (56.0%, 32.0%, and 12.0%, respectively) when three or more adult males were present. With only two pack males, alpha and beta individuals shared reproduction nearly equally (55.2% and 44.8%, respectively), and litters of mixed paternity were discovered on eight of 15 (53.3%) occasions. A skewed adult sex-ratio and frequent alpha mortalities for females and behavioral aggression in males allowed most individuals to attain dominant status in their lifetime, creating a constantly shifting social hierarchy. Genetic parentage results corresponded to reported hormone profiles, suggesting physiological suppression in some lower-ranked individuals of both sexes. Thus, a combination of demographic, behavioral, and hormonal proximate factors mediates reproductive partitioning in wild dogs. We conclude that reproductive sharing can be significant in this species, especially for males that have less robust suppressive mechanisms than females.The Smithsonian Institution Undersecretary for Science Endowment, University of Pretoria, Rotterdam Zoo Thandiza Fund, Humboldt State University, Conservation Endowment Fund of the Association of Zoos and Aquariums, Disney Wildlife Conservation Fund, Knowsley Safari Park, DST-NRF Centre of Excellence for Invasion Biology, Khaki Fever Work Wear, Ezemvelo KwaZulu-Natal Wildlife, Pittsburgh Zoo Conservation Fund, and the Morris Animal Foundation. International travel was generously provided by British Airways

Sampling error in non-invasive genetic analyses of an endangered social carnivore

Modern non-invasive genetic technologies are useful in studies of rare and difficult-to-observe species. An examination of endangered African wild dog (Lycaon pictus) faecal DNA revealed that 11.4% of samples were assigned incorrectly to an individual. Sampling mistakes in the field are not normally considered in non-invasive genetic assessments, but can be a significant source of error. To ensure meticulous data interpretation, non-invasive genetic studies should track and report sampling inaccuracies.This research was supported by Smithsonian Institution, University of Pretoria, Rotterdam Thandiza Fund, Humboldt State University, Association of Zoos and Aquariums, Disney Wildlife Conservation Fund, Knowsley Safari Park, DST-NRF Centre of Excellence for Invasion Biology, Pittsburgh Zoo and Morris Animal Foundation

A survey of internal parasites in free-ranging African wild dogs (Lycaon pictus) from KwaZulu-Natal, South Africa

A study was undertaken between 1 January 2006 and 16 February 2007 to identify haemoparasites and gastrointestinal parasites infecting African wild dogs (Lycaon pictus) in KwaZulu-Natal (KZN) province, South Africa. Blood and faecal samples were opportunistically collected from wild dogs immobilized for collaring or translocation purposes (n = 24). Three common domestic canine gastrointestinal parasites, Toxocara canis, Dipylidium caninum and Ancylostoma spp., and two genera of canid protozoan GI parasites, Sarcocystis and Isospora, were identified in 12 fresh faecal samples. The seroprevalence of Ehrlichia canis from 24 individual serum samples analysed was 83%. However, only 21% of the 14 whole-blood smears evaluated for the presence of E. canis morulae within monocytes were positive. Twelve whole-blood smears were evaluated for the presence of Babesia canis trophozoites within erythrocytes and revealed 0% prevalence. Although there is currently no evidence of direct parasite-related mortality in the KZN population, the presence of internal parasites may be more detrimental to the overall health status of African wild dogs with immunosuppression as a result of other disease conditions, translocation stress, or inbreeding depression

DOI:10.1017/S1367943003003263 Printed in the United Kingdom Altered behaviour in spotted hyenas associated with increased human

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