Lycaon Pictus Research Articles

African wild dogs (Lycaon pictus) show differences in diet composition across landscape types in Kruger National Park, South Africa

Abstract The Kruger National Park (KNP) is home to the last genetically viable, minimally managed population of African wild dogs (Lycaon pictus, wild dogs) in South Africa. Until 2004, this population remained stable, but since has been declining. In this study, we aimed to improve our understanding of the ecology of KNP wild dogs by estimating the relative contribution of different prey types to their diet across landscape types. Based on a Bayesian mixing model, we assessed wild dog diet and foraging preferences using stable isotope analysis. We sampled 73 individuals from 40 packs found in six different landscape types. In thickets, packs predominantly prey on small browsing and mixed-feeding species (accounting for ~73% of their diet), but occasionally hunt large grazers (~24%) and large browsers (~3%). In open landscape types where lions (Panthera leo) are more or less absent, such as in the Lowveld sour bushveld, wild dogs prey on large browsers and large grazers (~67%). Our results demonstrate that KNP wild dogs occupy a broader ecological niche than previously thought, with small browsers forming an integral part of their diet. We also present the first data describing differences in wild dog diet–tissue discrimination factors for tail hair and whiskers compared to respective stable nitrogen (δ15N) and carbon (δ13C) values obtained from feces of captive wild dogs, as well as from those of South Africa’s broader managed metapopulation. While these data should be considered preliminary, we suggest that until wild dog diet–tissue discrimination factors are calculated through a controlled feeding study, the discrimination factors calculated for the gray wolf (Canis lupus) should be used for wild dog-related isotope studies, rather than the often cited values for red foxes (Vulpes vulpes).

Environment considerations on the spread of rabies among African wild dogs (Lycaon pictus) with control measures

Wildlife conservation is crucial in preventing endangered species from becoming extinct, and disease outbreaks is one of the biggest threats. Rabies is one of the devastating viruses that can almost be impossible to control once an outbreak occurs. There is no effective treatment or cure of rabies once symptoms show. In this work, we propose euthanasia of infected Lycaon pictus dogs as a control strategy to reduce the spread of the virus. We propose a simple deterministic SEI‐type rabies model that takes into account the contaminated environment and the euthanasia of infectious dogs to better understand the transmission and progression dynamics of the disease, as well as to seek to predict the effectiveness of this control strategy. Qualitative analysis and numerical simulations are provided to support our findings.

Collaboration for conservation: Assessing countrywide carnivore occupancy dynamics from sparse data

AbstractAimAssessing the distribution and persistence of species across their range is a crucial component of wildlife conservation. It demands data at adequate spatial scales and over extended periods of time, which may only be obtained through collaborative efforts, and the development of methods that integrate heterogeneous datasets. We aimed to combine existing data on large carnivores to evaluate population dynamics and improve knowledge on their distribution nationwide.LocationBotswana.MethodsBetween 2010 and 2016, we collated data on African wild dog, cheetah, leopard, brown and spotted hyaena and lion gathered with different survey methods by independent researchers across Botswana. We used a multi‐species, multi‐method dynamic occupancy model to analyse factors influencing occupancy, persistence and colonization, while accounting for imperfect detection. Lastly, we used the gained knowledge to predict the probability of occurrence of each species countrywide.ResultsWildlife areas and communal rangelands had similar occupancy probabilities for most species. Large carnivore occupancy was low in commercial farming areas and where livestock density was high, except for brown hyaena. Lion occupancy was negatively associated with human density; lion and spotted hyaena occupancy was high where rainfall was high, while the opposite applied to brown hyaena. Lion and leopard occupancy remained constant countrywide over the study period. African wild dog and cheetah occupancy declined over time in the south and north, respectively, whereas both hyaena species expanded their ranges. Countrywide predictions identified the highest occupancy for leopards and lowest for the two hyaena species.Main ConclusionsWe highlight the necessity of data sharing and propose a generalizable analytical method that addresses the challenges of heterogeneous data common in ecology. Our approach, which enables a comprehensive multi‐species assessment at large spatial and temporal scales, supports the development of data‐driven conservation guidelines and the implementation of evidence‐based management strategies nationally and internationally.

Low apex carnivore density does not release a subordinate competitor when driven by prey depletion

Conservation of competitively subordinate carnivores presents a difficult challenge because they are limited by dominant competitors. Prey depletion is one of the leading causes of large carnivore decline worldwide, but little is known about the net effect of prey depletion on subordinate carnivores when their dominant competitors are also reduced. African wild dogs are often limited by high densities of dominant competitors, particularly lions. We measured African wild dog density and survival, using mark-recapture models fit to 8 years of data from 425 known individuals in the Greater Kafue Ecosystem, Zambia. The GKE is affected by prey depletion, particularly of large herbivores, and thus the density of lions is significantly lower than ecologically comparable ecosystems. Counter to expectations from mesopredator release theory, wild dog density in GKE was far lower than comparable ecosystems with higher lion and prey density, though annual survival rates were comparable to large and stable populations. Average pack size was small and home range size was among the largest recorded. Our results show that low lion density did not competitively release the GKE wild dog population and we infer that the low density of wild dogs was a product of low prey density. Our results suggest that there is an optimal ratio of prey and competitors at which wild dogs achieve their highest densities. This finding has immediate implications for the conservation of the endangered African wild dog, and broad implications for the conservation of subordinate species affected by resource depletion and intraguild competition.

English

Communities living adjacent to protected areas tend to express more willingness to coexist with large carnivores in their areas when they receive tangible benefits. The aim of this study was to explore people’s willingness to coexist with large carnivores, including lions (Panthera leo), leopards (Panthera pardus), cheetahs (Acinonyx jubatus), spotted hyenas (Crocuta crocuta), African wild dogs (Lycaon pictus) and black-backed jackals (Canis mesomelas schmidti). The authors used a pre-test and post-test approach by implementing a chemoprophylactic program as a conservation incentive among the Maasai and Sonjo tribes living in the eastern Serengeti, Tanzania. Chemoprophylaxis is the prevention of infectious disease by using chemical agents. The pre-test results showed that both tribes had low willingness to coexist with these large carnivores. Of the two tribes, the Sonjo tribe was less willing than the Maasai tribe. Our post-test results indicated an increase in willingness to coexist with large carnivores in their area because the livestock loss due to large carnivore depredation was significantly lower than that caused by diseases in both tribes. Therefore, this study calls for more conservation incentives to local people to promote their willingness to coexist with large carnivores in their areas.   Key words: Coexistence, depredation, diseases, large carnivores, livestock, Maasai and Sonjo tribes.

The characteristics and consequences of African wild dog (Lycaon pictus) den site selection

The characteristics and consequences of African wild dog (Lycaon pictus) den site selection

DETERMINATION OF VERTEBRAL HEART SCALE AND ECHOCARDIOGRAPHIC MEASUREMENTS IN HEALTHY ANESTHETIZED AFRICAN WILD DOGS (LYCAON PICTUS) IN HUMAN CARE.

Cardiac disease is an important cause of mortality in African wild dogs in human care. Vertebral heart scale (VHS) is a well-documented objective measure of cardiac size and is commonly used in domestic dogs. The VHS of 63 clinically healthy African wild dogs housed in zoological institutions was retrospectively calculated. Using the robust method of reference interval (RI) calculation, the RI for VHS in captive African wild dogs was 9.3-10.8. Echocardiographic measurements from 16 clinically healthy and 2 African wild dogs with preclinical dilated cardiomyopathy are reported. The cardiac biomarkers N-terminal pro-B-type natriuretic peptide (NT-proBNP) and cardiac troponin I (cTnI) were measured in a subset of African wild dogs. The median plasma NT-proBNP measurement was 845 pM/L (range 366-1,388) and the median serum cTnI measurement was 0.02 ng/ml (0.01-0.04). These data can be used for the assessment and identification of cardiac disease in this endangered species.

African Wild Dog Movement Ecology in a Small Protected Area in South Africa

Dramatic population declines of African wild dogs (Lycaon pictus) led to a managed metapopulation approach for wild dog conservation in South Africa. Monitoring the survival and habitat use of packs reintroduced into protected areas (PAs) is an essential part of adaptive management and improving the health and, ultimately, the survival of the metapopulation. Our study describes the territoriality and habitat selection of a pack of wild dogs reintroduced into Manyoni Private Game Reserve (219 km2) in northern KwaZulu-Natal, South Africa. Despite being introduced into a small PA, the pack only utilized half their available space (121 km2) and avoided the central areas of the reserve. Post hoc analysis of African lion (Panthera leo) localities suggested competitive avoidance was a strong factor in shaping the habitat usage of the pack; however, further research is required. Habitat selection also varied seasonally and with denning. Ultimately, we showed that spatio-temporal analyses can help identify high-risk areas within wild dog territories, such as hotspots of activity along fencelines. These analyses can then be used to increase targeted management of these areas, such as improving the maintenance of well-used fencelines, which is an important consideration for the sustained success of the metapopulation across small PAs.

Into the unknown – my time in Zimbabwe with the African Painted Dogs

Veterinary nursing can take you anywhere. In September 2019, I was lucky enough to work with Wildlife Vets International (WVI) and Painted Dog Conservation to provide a neutering and vaccination service to the local communities of Zimbabwe. Vaccinating local cats and dogs can help prevent the spread of diseases having devastating effects on the species. The aim of this article is to encourage all veterinary nurses to give their time to any animal welfare or conservation projects and to share my experiences of neutering projects of Zimbabwe and the plight of the African Painted Dogs.

Hunter-Gatherers in context: Mammal community composition in a northern Tanzania landscape used by Hadza foragers and Datoga pastoralists.

In many regions of sub Saharan Africa large mammals occur in human-dominated areas, yet their community composition and abundance have rarely been described in areas occupied by traditional hunter-gatherers and pastoralists. Surveys of mammal populations in such areas provide important measures of biodiversity and provide ecological context for understanding hunting practices. Using a sampling grid centered on a Hadza hunter-gatherer camp and covering 36 km2 of semi-arid savannah in northern Tanzania, we assessed mammals using camera traps (n = 19 stations) for c. 5 months (2,182 trap nights). In the study area (Tli’ika in the Hadza language), we recorded 36 wild mammal species. Rarefaction curves suggest that sampling effort was sufficient to capture mammal species richness, yet some species known to occur at low densities in the wider area (e.g. African lions, wildebeest) were not detected. Relative abundance indices of wildlife species varied by c. three orders of magnitude, from a mean of 0.04 (African wild dog) to 20.34 capture events per 100 trap-nights (Kirk’s dik dik). To contextualize the relative abundance of wildlife in the study area, we compared our study’s data to comparable camera trap data collected in a fully protected area of northern Tanzania with similar rainfall (Lake Manyara National Park). Raw data and negative binomial regression analyses show that wild herbivores and wild carnivores were generally detected in the national park at higher rates than in the Hadza-occupied region. Livestock were notably absent from the national park, but were detected at high levels in Tli’ika, and cattle was the second most frequently detected species in the Hadza-used area. We discuss how these data inform current conservation efforts, studies of Hadza hunting, and models of hunter-gatherer foraging ecology and diet.

Developments in data science solutions for carnivore tooth pit classification

Competition for resources is a key question in the study of our early human evolution. From the first hominin groups, carnivores have played a fundamental role in the ecosystem. From this perspective, understanding the trophic pressure between hominins and carnivores can provide valuable insights into the context in which humans survived, interacted with their surroundings, and consequently evolved. While numerous techniques already exist for the detection of carnivore activity in archaeological and palaeontological sites, many of these techniques present important limitations. The present study builds on a number of advanced data science techniques to confront these issues, defining methods for the identification of the precise agents involved in carcass consumption and manipulation. For the purpose of this study, a large sample of 620 carnivore tooth pits is presented, including samples from bears, hyenas, jaguars, leopards, lions, wolves, foxes and African wild dogs. Using 3D modelling, geometric morphometrics, robust data modelling, and artificial intelligence algorithms, the present study obtains between 88 and 98% accuracy, with balanced overall evaluation metrics across all datasets. From this perspective, and when combined with other sources of taphonomic evidence, these results show that advanced data science techniques can be considered a valuable addition to the taphonomist’s toolkit for the identification of precise carnivore agents via tooth pit morphology.

Review of Methods Used for Diagnosing Tuberculosis in Captive and Free-Ranging Non-Bovid Species (2012-2020).

The Mycobacterium tuberculosis complex (MTBC) is a group of bacteria that cause tuberculosis (TB) in diverse hosts, including captive and free-ranging wildlife species. There is significant research interest in developing immunodiagnostic tests for TB that are both rapid and reliable, to underpin disease surveillance and control. The aim of this study was to carry out an updated review of diagnostics for TB in non-bovid species with a focus predominantly on those based on measurement of immunity. A search was carried out to identify relevant papers meeting a pre-defined set of inclusion criteria. Forty-one papers were identified from this search, from which only twenty papers contained data to measure and compare diagnostic performance using diagnostic odds ratio. The diagnostic tests from each study were ranked based on sensitivity, specificity, and diagnostic odds ratio to define high performing tests. High sensitivity and specificity values across a range of species were reported for a new antigenic target, P22 complex, demonstrating it to be a reliable and accurate antigenic target. Since the last review of this kind was undertaken, the immunodiagnosis of TB in meerkats and African wild dogs was reported for the first time. Suid species showed the most consistent immunological responses and highlight a potential dichotomy between humoral and cellular immune responses.

Shedding of Mycobacterium bovis in respiratory secretions of free-ranging wild dogs (Lycaon pictus): Implications for intraspecies transmission.

It has recently been discovered that Mycobacterium bovis (M.bovis) causes disease in the endangered African wild dog (Lycaon pictus) in areas endemic for bovine tuberculosis (bTB), including the Kruger National Park (KNP). However, information on M.bovis infection dynamics within this species is limited and requires investigation as M.bovis can cause conservation consequences due to movement restrictions, crucial for genetic management. This study had two aims: firstly, to investigate mycobacterial shedding in free-ranging wild dogs from KNP by culturing oropharyngeal swab (OS) and bronchoalveolar lavage (BAL) samples. Secondly, to determine the relationship between ante-mortem culture and interferon gamma release assay (IGRA) results as well as agreement between OS culture and BAL culture results. Mycobacterial culture revealed that 6 of 173 (3.5%) OS samples and 1 of 32 (3.1%) BAL samples (from 7 different wild dogs) were M.bovis culture positive, suggesting that wild dogs can shed M.bovis through respiratory secretions. However, the possibility of contamination by ingestion of infected prey cannot be excluded in wild dogs with positive OS culture results. Furthermore, the test outcomes between IGRA and culture (OS and BAL) differed substantially. Samples from 172 wild dogs were available for IGRA screening and 134 had positive results (detectable M. bovis immune sensitization). Seven wild dogs had culture-positive results, which included one additional wild dog that did not have an IGRA result (total 173 wild dogs). Out of these 7 M. bovis culture-positive wild dogs, 3 were IGRA positive initially, however, after repeat sampling and testing, 5 out of 7 were IGRA positive. These findings suggest that intraspecies transmission of M.bovis may be possible among wild dogs. Although the risk of intraspecies transmission is currently unknown, this knowledge is important for assessing the risk of M.bovis transmission from infected wild dogs to uninfected populations during translocations.

Rapid diagnosis of infectious diseases: The role of giant African pouched rats, dogs and honeybees

Early detection of infection in an individual is an important strategy to prevent transmission and spread of the infection – in the community or among patients admitted in a health care facility. Over the past decade, there have been rapid advances in technology in an attempt to provide rapid, accurate tests for diagnosis of infectious diseases. With this in perspective, the use of animals’ superior olfactory sensitivity to sniff out infectious diseases holds promise.

Bound within boundaries: Do protected areas cover movement corridors of their most mobile, protected species?

Abstract Conserving and managing large portions of land to connect wildlife reserves is an increasingly used strategy to maintain and restore connectivity among wildlife populations. Boundaries of such conservation areas are often determined based on expert opinion and socio‐political constraints, yet the extent to which they match species' movement corridors is rarely examined. This is mainly due to a lack of data, particularly on wide‐ranging movement behaviour such as dispersal. Nevertheless, empirically assessing the adequacy of protected areas is key for the implementation of targeted management actions and efficient use of limited conservation funds. Between 2011 and 2019, we collected high‐resolution GPS data on 16 dispersing African wild dog Lycaon pictus coalitions from a free‐ranging population in the Kavango–Zambezi Transfrontier Conservation Area (KAZA‐TFCA). Spanning five countries and 520,000 km2, the KAZA‐TFCA is the world's largest transboundary conservation area and a prime example for international conservation efforts. We used integrated step selection analysis to estimate habitat selection of dispersers and to create a permeability surface for the KAZA‐TFCA. We compared landscape permeability across different regions within the KAZA‐TFCA as well as outside its boundaries. Lastly, we calculated least‐cost paths and corridors to verify that major movement routes were adequately encompassed within the KAZA‐TFCA. Permeability within the boundaries of the KAZA‐TFCA was more than double compared to areas outside it. Furthermore, we observed a fivefold permeability difference among the five KAZA‐TFCA countries. We also showed that major movement corridors of wild dogs ran within the KAZA‐TFCA, although some minor routes remained formally unprotected. Differences in permeability were mainly related to different degrees of human activities across regions, and to the presence or absence of rivers, swamps and open water. The relationship between permeability and other landscape features was less pronounced. Synthesis and applications. In this study, we showed how pertinent dispersal data of a highly mobile species can be used to empirically evaluate the adequacy of already existing or planned protected areas. Furthermore, we observed regional differences in landscape permeability that highlight the need for a coordinated effort towards maintaining or restoring connectivity, especially where transboundary dispersal occurs.

Spatial heterogeneity facilitates carnivore coexistence.

Competitively dominant carnivore species can limit the population sizes and alter the behavior of inferior competitors. Established mechanisms that enable carnivore coexistence include spatial and temporal avoidance of dominant predator species by subordinates, and dietary niche separation. However, spatial heterogeneity across landscapes could provide inferior competitors with refuges in the form of areas with lower competitor density and/or locations that provide concealment from competitors. Here, we combine temporally overlapping telemetry data from dominant lions (Panthera leo) and subordinate African wild dogs (Lycaon pictus) with high-resolution remote sensing in an integrated step selection analysis to investigate how fine-scaled landscape heterogeneity might facilitate carnivore coexistence in South Africa's Hluhluwe-iMfolozi Park, where both predators occur at exceptionally high densities. We ask whether the primary lion-avoidance strategy of wild dogs is spatial avoidance of lions or areas frequented by lions, or if wild dogs selectively use landscape features to avoid detection by lions. Within this framework, we also test whether wild dogs rely on proactive or reactive responses to lion risk. In contrast to previous studies finding strong spatial avoidance of lions by wild dogs, we found that the primary wild dog lion-avoidance strategy was to select landscape features that aid in avoidance of lion detection. This habitat selection was routinely used by wild dogs, and especially when in areas and during times of high lion-encounter risk, suggesting a proactive response to lion risk. Our findings suggest that spatial landscape heterogeneity could represent an alternative mechanism for carnivore coexistence, especially as ever-shrinking carnivore ranges force inferior competitors into increased contact with dominant species.

Enclosure Use as a Measure of Behavioral Welfare in Zoo-Housed African Wild Dogs (Lycaon pictus)

African wild dogs Lycaon pictus are a popularly exhibited zoo animal, frequently housed in groups to represent their natural packs in the wild. While such group housing is common, the effects of changes to that group are seldom directly investigated. This study examined the enclosure use of three African wild dog siblings located at the Woodland Park Zoo. The wild dogs were observed during a period of several weeks, during which one of the dogs was periodically removed from the group. Groupings of the wild dogs were examined during three conditions: (1) ALL 3, when all three dogs were on-exhibit, (2) MIXED, when one of the dogs was held off-exhibit, and (3) ALL 2, when only two animals remained in the enclosure and on-exhibit. Removal of one of the dogs from the on-exhibit portion of the enclosure (MIXED and ALL 2 conditions) significantly modified overall area usage and variability in enclosure use (as measured via Entropy, a single measure of area use variability) for the two remaining on-exhibit wild dogs. The results suggest that overall enclosure use, with attention to variability in enclosure areas used, can function as a relevant behavioural welfare measure for group-housed zoo animals, particularly when direct measures of behaviours are inconclusive.

The successful reintroduction of African wild dogs (Lycaon pictus) to Gorongosa National Park, Mozambique.

Large carnivores have experienced widespread extirpation and species are now threatened globally. The ecological impact of the loss of large carnivores has been prominent in Gorongosa National Park, Mozambique, after most were extirpated during the 1977-92 civil war. To remedy this, reintroductions are now being implemented in Gorongosa, initiating with endangered African wild dogs (Lycaon pictus), hereafter 'wild dogs'. We describe the first transboundary translocation and reintroduction of founding packs of wild dogs to Gorongosa over a 28-month study period and evaluate the success of the reintroduction based on five key indicator categories. We also assess how wild dog space use and diet influenced their success. We found that pre-release, artificial pack formation in holding enclosures aided group cohesion and alpha pair establishment. Post-release, we also observed natural pack formations as a result of multiple dispersal events. Founder and naturally formed packs produced pups in two of the three breeding seasons and packs successfully recruited pups. Survival rate for all wild dogs was 73% and all mortality events were from natural causes. Consequently, the population grew significantly over the study period. All indicators of success were fully achieved and this study documents the first successful reintroduction of wild dogs into a large, unfenced landscape in Mozambique and only the second on the continent. Potential mechanisms underlying these early successes were the avoidance of habitats intensively used by lions, dietary partitioning with lion, avoidance of human settlements, and Gorongosa's management strategy. We predict further population expansion in Gorongosa given that 68% of the park is still unused by wild dogs. This expansion could be stimulated by continued reintroductions over the short- to medium-term. Recovery of wild dogs in Gorongosa could aid in the re-establishment of a larger, connected population across the greater Gorongosa-Marromeu landscape.

Fencing affects African wild dog movement patterns and population dynamics

AbstractWildlife fences are often considered an important tool in conservation. Fences are used in attempts to prevent human–wildlife conflict and reduce poaching, despite known negative impacts on landscape connectivity and animal movement patterns. Such impacts are likely to be particularly important for wide-ranging species, such as the African wild dogLycaon pictus, which requires large areas of continuous habitat to fulfil its resource requirements. Laikipia County in northern Kenya is an important area for wild dogs but new wildlife fences are increasingly being built in this ecosystem. Using a long-term dataset from the area's free-ranging wild dog population, we evaluated the effect of wildlife fence structure on the ability of wild dogs to cross them. The extent to which fences impeded wild dog movement differed between fence designs, although individuals crossed fences of all types. Purpose-built fence gaps increased passage through relatively impermeable fences. Nevertheless, low fence permeability can lead to packs, or parts of packs, becoming trapped on the wrong side of a fence, with consequences for population dynamics. Careful evaluation should be given to the necessity of erecting fences; ecological impact assessments should incorporate evaluation of impacts on animal movement patterns and should be undertaken for all large-scale fencing interventions. Where fencing is unavoidable, projects should use the most permeable fencing structures possible, both in the design of the fence and including as many purpose-built gaps as possible, to minimize impacts on wide-ranging wildlife.

Reproductive state influences the degree of risk tolerance for a seasonally breeding mesopredator

AbstractThe risk of predation can alter the way animals perceive costs and benefits in their environment, on which foraging decisions are made. To maximize fitness, animals with offspring show the most pronounced alteration in behavior because mothers experience increased nutritional requirements and increased vulnerability to predation. Therefore, the tolerance of risk is shaped, in part, by reproductive state. Like prey species, mesopredators balance a trade-off between food and predation to maximize fitness. However, few studies have acknowledged its importance. We investigated how mesopredators may alter their space use between periods when young are and are not vulnerable. Investigating the fine-scale space use of 19 packs of African wild dogs Lycaon pictus in the Kruger National Park, we found lower risk tolerance of denning packs; they re-visited area less frequently as lion and impala density increased and thus reduced the likelihood of risky encounters by avoiding areas where both risk and reward were high. By contrast, non-denning packs re-visited area less frequently as lion density increased and impala density decreased and thus avoided areas where reward was low, especially if risk was high. These results suggest that wild dogs shift their patterns of space use when the pack is most vulnerable. Ultimately, we found evidence of decreased risk tolerance by denning packs, likely because of increased vulnerability of lactating mothers and immobile pups. More broadly, our findings suggest that risk tolerance is dependent on reproductive state for mesopredators and should be considered as a possible mechanism for other mesopredators as well.