Lycaon Pictus Research Articles

Effect of Carcass Feeds on Feeding Behavior and Social Interactions in Zoo-Based African Wild Dogs (Lycaon pictus).

Management of African wild dogs (Lycaon pictus) in zoos involves several challenges, including the difficulty of providing appropriate stimulation and enrichment for naturally wide-ranging, energetic, cursorial hunters. Perhaps consequently, zoo packs can exhibit bouts of extreme intra-pack aggression rarely seen in the wild. As with other species, considerable efforts are required to balance the retention and exhibition of wild-type behaviors, against ensuring that the nutritional and welfare needs of individual group-living animals are met. While some behaviors, such as hunting and wide-ranging movements are impossible to mimic in zoos, the provision of food may be refined to allow natural feeding behavior to be displayed. We conducted a feeding experiment on a breeding pack of nine African wild dogs at Taronga Western Plains Zoo in Australia, presenting food in three treatments (individual pieces, butchered carcasses, and whole carcasses) to determine whether: (1) natural age-related patterns of feeding behavior were observed; (2) food type or presentation affected feeding behavior, duration, and interactions. Free-ranging African wild dogs exhibit an age-based feeding structure at kill sites that is rare in other species. We found that carcass and butchered carcass feeds more closely exhibited the age-based feeding observed in the wild. The pack spent twenty times as long consuming carcasses than food presented as individual pieces, with consumption times matching those in the wild. Carcass and butchered carcass feeds also increased the number and rate of interactions over food compared to individual pieces, with a high proportion of interactions resulting in sharing outcomes. This suggests that carcass feeds allow the exhibition of natural patterns of behavior without increasing the risk of negative social interactions. Our results highlight the importance and possibility of managing socially complex carnivores through husbandry that balances the display of natural behavior with positive animal welfare.

EFFECTIVE ANTIBODY RESPONSE OF AFRICAN WILD DOGS (LYCAON PICTUS) TO CANINE DISTEMPER VACCINATION WITH A LIVE ATTENUATED VACCINE.

Vaccinating African wild dogs (Lycaon pictus) against canine distemper virus (CDV) using live attenuated vaccines (LAV) has been controversial because of limitations in the vaccines' effectiveness and safety. However, CDV is a significant pathogen for African wild dogs, and CDV LAV are currently the only vaccines readily available on the African continent, making them a crucial tool for in situ conservation. There are few studies exploring immunogenicity of CDV LAV, and even less information pertaining to optimal vaccination protocols. This study reports the use of CDV LAV VanguardTM Plus 5/L in 16 African wild dogs from two sibling groups with initial inoculation at approximately 6-7 wk of age. The majority (81%, n = 13) of pups generated protective titers after initial vaccination. One pup died of CDV-suspected neurological disease within 17 d of initial vaccination. All remaining dogs received a second dose, and 100% of those achieved protective immunity (as per domestic dog reference values). Protective antibody titers were maintained throughout the sampling period of 284 and 373 d from the second vaccination. The risk of possible vaccine-induced disease cannot be excluded, but may be a sustainable risk compared with the protective potential of CDV LAV for African wild dogs.

Determinants of attitude toward African wild dog (Lycaon pictus) and other large carnivores in rural communities adjacent to the Mid-Zambezi Wildlife Area, Zimbabwe

ABSTRACT Understanding psychological and sociological factors affecting human attitudes toward carnivores assists in promoting co-existence. We interviewed respondents in rural communities adjacent to Zimbabwe’s Mid-Zambezi Wildlife Area to determine which demographic, regional and human–wildlife conflict-related variables affect attitudes toward African wild dog and other large carnivores. Variables determining attitude varied per species, however; women held less positive views of carnivores. Attitudes toward African wild dog were positively related to knowledge level and conservation support. Attitudes were most negative toward species which caused considerable conflict (spotted hyaena, lion, leopard). Age and being part of CAMPFIRE had a positive impact, while distance from the protected area negatively affected attitudes toward those conflict prone species. Overall, perceived threat to livestock and human life were main reasons to dislike carnivores, even when conflict was minimal or absent. Respondents used conventional mitigation methods during nighttime, but hardly used daytime herding to prevent depredation of livestock.

Prey depletion, interspecific competition, and the energetics of hunting in endangered African wild dogs, Lycaon pictus

Large herbivores are in decline in much of the world, including sub-Saharan Africa, and true apex carnivores like the lion (Panthera leo) decline in parallel with their prey. As a consequence, competitively subordinate carnivores like the African wild dog (Lycaon pictus) are simultaneously experiencing a costly reduction in resources and a beneficial reduction in dominant competitors. The net effect is not intuitively obvious, but wild dogs' density, survival, and reproduction are all low in areas that are strongly affected by prey depletion. To assess whether these correlations are causal, we tested the hypothesized mechanism, using data from 13 wild dog packs in two ecosystems to relate the energetic costs and benefits of hunting to variation in prey density, while controlling for the effects of local lion density, pack size, the number of dependent pups, and the level of protection. All of these variables affected the energetic costs and benefits of hunting. In areas with low prey density, the magnitude of movements and vectorial dynamic body acceleration (a measure of energy expenditure) both increased, the mass of killed prey decreased, and the number of kills per day did not change detectably. Programs to reduce or reverse the decline of large herbivore populations should be an effective means of improving the status of endangered subordinate competitors like the wild dog, and should be a high priority. Our results demonstrate the utility of research that integrates data from biomonitoring with direct, long-term observation of endangered species, their competitors, and their resources.

An epidemiological study of canine lymphoma in South Africa.

Breed, age, and sex predispositions for canine lymphoma have been reported for various geographical locations. However, epidemiological information concerning canine lymphoma in South Africa is scarce. The aim of the study was to describe the epidemiological features of canine lymphoma and the frequency of World Health Organization (WHO) classification subtypes in South Africa. A retrospective, case-control study was performed that included 342 cases with a histopathological diagnosis of canine lymphoma matched with 342 canine non-lymphoma control cases. Associations between canine lymphoma and breed, age, sex, and neutering status were assessed using univariate and multivariable conditional logistic regression. Associations were reported as odds ratios and significance set as p≤ 0.05. Breed was significantly associated with canine lymphoma, but not age, sex, or neutering status. Median population age was eight years, with a male-to-female ratio of 1.2:1. The Boerboel had an increased risk (OR = 1.63, CI = 1.02-2.62, p = 0.002) and the Yorkshire Terrier a decreased risk (OR = 0.59, CI = 0.38-0.93, p = 0.050) of having canine lymphoma. Immunophenotyping was performed on 119 (35%) cases, of which 82 (69%) were B-cell, 34 (29%) T-cell and three (2%) neither. WHO subtype was available for 88 cases; of these 66 (75%) were diffuse large B-cell lymphoma (DLBCL) with remaining subtypes each ≤ 7%. This study identified a breed predisposition for canine lymphoma in the Boerboel, a South African mastiff-type dog, but significant associations were not detected for age, sex, and other breeds. The frequency of immunophenotypes and WHO subtypes was similar to previous studies in other locations.

The function of putative appeasement behaviour for access to food in African painted dogs

Abstract In some group-living species that share food, interindividual disagreement on access to food is mediated by several types of negotiation, ranging from appeasing the current owner to reduce aggression and gain access to the food, to harassment where non-owners assert their presence and apply insistent pressure until owners give up their food. In some species, non-owners employ specific behaviours used in other social contexts during negotiation, which makes it challenging to discern their precise functions. The core prediction of the harassment hypothesis is that intense pressure by beggars makes owners abandon their food and leads to food monopolisation, which is not predicted by the appeasement hypothesis. In the African painted dog (Lycaon pictus), non-owners assume a low posture and produce high-pitched vocalisations — a suite of behaviours considered appeasement in non-feeding contexts. This study examined whether these behaviours, referred to collectively as putative appeasement behaviour (PAB), serve as appeasement in the context of feeding or whether they may also, or only, be used for harassment. To this end, we used behavioural experiments in captive parent–offspring or full sibling pairs. Individuals showed more frequent PAB when offered food that could not be easily shared (one vs. two bones). As aggression also only occurred under that condition, PAB seems to have a function in appeasement. However, we observed a positive effect of PAB on food monopolisation by PAB actors but not on co-feeding. Persistent PAB led to monopolisation, indicating that these behaviours serve as a form of harassment in feeding. We did not observe reciprocity between paired individuals, another possible form of food monopolisation besides appeasement and harassment. In conclusion, PAB in the African painted dog functions as both appeasement and harassment, and this highly tolerant species employs negotiation strategies in feeding.

Historical ostriches in the Libyan Desert, with ecological and taxonomic considerations

Many historical records extend the known range of the African ostrich Struthio camelus to include almost the entire state territory of Libya. This significant expansion augments the spatial potentialities to reintroduce captive-bred progeny of the endangered red-necked ostriches (S. c. camelus) from zoos and wildlife centres. The latest Libyan ostriches lingered in Cyrenaica and Fezzan into the late 19th century, and presumably near Kufra into the 1930s. Their extermination coincided with the occupation by colonial European administrations. These east Saharan biotopes are extraordinarily resource-poor and climatically challenging due to wide thermal amplitudes and extreme drought. Old photographs from Kufra and Wadi Howar leave undecided if the Libyan ostriches adhered to the subspecies S. c. camelus, which appears possible, or if additional, partly substantiated but yet unconfirmed claims should be heeded which demand up to three subspecies in North Africa. A review of taxonomic interpretations reveals a weak foundation by reliable data of a pan-Saharan subspecies S. c. camelus, and additional research is suggested to provide a sound taxonomic concept, not least for the management of various regional breeding lineages in zoos, which safeguard the survival of this endangered bird. As an auxiliary finding, African wild dogs (Lycaon pictus) are attested as inhabitants of the southern Libyan Desert until the 1930s, where they had preyed upon the now equally extinct ostriches.

All in the Details: A First Assessment for the Viability of Metabarcoding in Diet Composition Analysis of African Wild Dogs (Lycaon pictus).

DNA metabarcoding is a contemporary technique in diet composition studies and stands to fill key knowledge gaps left by traditional diet analysis methods. For endangered species such as the African wild dog (Lycaon pictus), the fulfilment of these knowledge gaps presents an opportunity for improved management practices and vulnerability assessments. There are an estimated ~600 African wild dogs remaining in South Africa. These dogs are generally understood to prey upon impala (Aepyceros melampus) and other medium-sized ungulates. Here, we present the first assessment of DNA metabarcoding as a valuable method for diet composition analysis of this highly social carnivore. DNA from faecal samples collected across seven landscape types in the Kruger National Park (KNP) was extracted and used to determine the presence of seven unique prey taxa, including novel species such as the Cape hare (Lepus capensis). Impala was identified as a prey item in all landscape types, complementing the diet preference prediction made with stable isotope analysis using the same samples and existing understanding of wild dog diet. Given recommended improvements, the application of DNA metabarcoding in wild dog diet analysis shows promising prospects for identifying novel prey species and validating previous records of this endangered canids diet.

Long-Distance, Transfrontier Carnivore Dispersals in Southern Africa.

Information on long-range dispersal in tropical carnivores is limited compared to their temperate counterparts. Here we present data on long-range, transboundary dispersals for three species of tropical carnivores: African wild dog (Lycaon pictus), African lion (Panthera leo), and spotted hyena (Crocuta crocuta). The dispersals we document in our savannah system are among the longest that have been recorded for African wild dog and African lion, while for spotted hyena one of our recorded dispersal events is of similar magnitude to the longest documented movements occurring among any carnivore species from around the world.

The comparative morphology of the oral cavity glands in captive South African painted dogs (Lycaon pictus pictus) and captive fennec foxes (Vulpes zerda) (Carnivora: Canidae)

BackgroundThe African painted dog is classified as a relic canid lineage, inhabiting areas south of the Sahara. The fennec fox is the smallest member of the Canidae family, found in the Arabian Peninsula and northern Sahara.MethodsThe gross anatomy and light microscopic examination of the oral cavity glands were studied in five adult captive South African painted dogs and five adult captive fennec foxes from the Wroclaw Zoological Garden, Poland. In this research, the zygomatic gland, monostomatic sublingual gland, polystomatic sublingual gland, mandibular gland, and parotid gland were examined for their topography, morphometry, histology, and histochemistry using hematoxylin and eosin, azan trichrome, mucicarmine, PAS, AB pH 1.0, AB pH 2.5, AB pH 2.5 PAS, and HID.ResultsWe found that the parotid glands were consistently the largest, followed by the mandibular and sublingual glands (both monostomatic and polystomatic). The zygomatic gland was the smallest in both South African painted dogs and fennec foxes. Interestingly, there were noticeable differences in the size, shape, and even composition of the secretory products between the two species. The zygomatic and polystomatic sublingual glands in the South African painted dog and the fennec fox were complex branched tubular. In the South African painted dog, the monostomatic gland was a branched tubular compound gland, while in the fennec fox, it was a branched tubuloalveolar compound gland. The mandibular gland in hunting dogs was a branched tubular compound gland, while in the fennec fox a branched tubuloalveolar compound gland. The parotid gland in the fennec fox was a branched acinar compound gland, whereas in the painted dog was a branched tubuloacinar.ConclusionsThe basic structure of their glands is similar to that of other terrestrial carnivores, indicating a shared evolutionary origin and function. However, differences in the composition of their secretory products can reflect adaptations to their specific diets. This research provides valuable insights for veterinary medicine and underscores the importance of further studies. By analyzing wild canid populations and including a broader range of species with diverse diets, we could gain a deeper understanding of how diet influences salivary gland morphology within the Canidae.

Droughts reshape apex predator space use and intraguild overlap.

Droughts are increasing in frequency and severity globally due to climate change, leading to changes in resource availability that may have cascading effects on animal ecology. Resource availability is a key driver of animal space use, which in turn influences interspecific interactions like intraguild competition. Understanding how climate-induced changes in resource availability influence animal space use, and how species-specific responses scale up to affect intraguild dynamics, is necessary for predicting broader community-level responses to climatic changes. Although several studies have demonstrated the ecological impacts of drought, the behavioural responses of individuals that scale up to these broader-scale effects are not well known, particularly among animals in top trophic levels like large carnivores. Furthermore, we currently lack understanding of how the impacts of climate variability on individual carnivore behaviour are linked to intraguild dynamics, in part because multi-species datasets collected at timescales relevant to climatic changes are rare. Using 11 years of GPS data from four sympatric large carnivore species in southern Africa-lions (Panthera leo), leopards (Panthera pardus), African wild dogs (Lycaon pictus) and cheetahs (Acinonyx jubatus)-spanning 4 severe drought events, we test whether drought conditions impact (1) large carnivore space use, (2) broad-scale intraguild spatial overlap and (3) fine-scale intraguild interactions. Drought conditions expanded space use across species, with carnivores increasing their monthly home range sizes by 35% (wild dogs) to 66% (leopards). Drought conditions increased the amount of spatial overlap between lions and subordinate felids (cheetahs and leopards) by up to 119%, but only lion-cheetah encounter rates were affected by these changes, declining in response to drought. Our findings reveal that drought has a clear signature on the space use of multiple sympatric large carnivore species, which can alter spatiotemporal partitioning between competing species. Our study thereby illuminates the links between environmental change, animal behaviour and intraguild dynamics. While fine-scale avoidance strategies may facilitate intraguild coexistence during periodic droughts, large carnivore conservation may require considerable expansion of protected areas or revised human-carnivore coexistence strategies to accommodate the likely long-term increased space demands of large carnivores under projected increases in drought intensity.

Spatial Risk Effects From Lions Compound Impacts of Prey Depletion on African Wild Dogs.

Prey depletion threatens many carnivore species across the world and can especially threaten low-density subordinate competitors, particularly if subordinates are limited to low densities by their dominant competitors. Understanding the mechanisms that drive responses of carnivore density to prey depletion is not only crucial for conservation but also elucidates the balance between top-down and bottom-up limitations within the large carnivore guild. To avoid predation, competitively subordinate African wild dogs typically avoid their dominant competitors (lions) and the prey rich areas they are associated with, but no prior research has tested whether this pattern persists in ecosystems with anthropogenically-reduced prey density, and reduced lion density as a result. We used spatial data from wild dogs and lions in the prey-depleted Greater Kafue Ecosystem to test if wild dogs continue to avoid lions (despite their low density), and consequently avoid habitats with higher densities of their dominant prey species. We found that although lion density is 3X lower than comparable ecosystems, wild dogs continue to strongly avoid lions, and consequently avoid habitats associated with their two most important prey species. Although the density of lions in the GKE is low due to prey depletion, their competitive effects on wild dogs remain strong. These effects are likely compounded by prey-base homogenization, as lions in the GKE now rely heavily on the same prey preferred by wild dogs. These results suggest that a reduction in lion density does not necessarily reduce competition, and helps explain why wild dogs decline in parallel with their dominant competitors in ecosystems suffering from anthropogenic prey depletion. Protecting prey populations within the few remaining strongholds for wild dogs is vitally important to avoid substantial population declines. Globally, understanding the impacts of prey depletion on carnivore guild dynamics should be an increasingly important area of focus for conservation.

A chromosome phased diploid genome assembly of African hunting dog (Lycaon pictus).

The African hunting dog (Lycaon pictus, 2n = 78) once ranged over most sub-Saharan ecosystems except its deserts and rainforests. However, as a result of (still ongoing) population declines, today they remain only as small fragmented populations. Furthermore, the future of the species remains unclear, due to both anthropogenic pressure and interactions with domestic dogs, thus their preservation is a conservation priority. On the tree of life, the hunting dog is basal to Canis and Cuon and forms a crown group with them, making it a useful species for comparative genomic studies. Here, we present a diploid chromosome-level assembly of an African hunting dog. Assembled according to Vertebrate Genomes Project guidelines from a combination of PacBio HiFi reads and HiC data, it is phased at the level of individual chromosomes. The maternal (pseudo)haplotype (mat) of our assembly has a length of 2.38 Gbp, and 99.36% of the sequence is encompassed by 39 chromosomal scaffolds. The rest is included in only 36 unplaced short scaffolds. At the contig level, the mat consists of only 166 contigs with an N50 of 39 Mbp. BUSCO (Benchmarking Universal Single-Copy Orthologue) analysis showed 95.4% completeness based on Carnivora conservative genes (carnivora_odb10). When compared with other available genomes from subtribe Canina, the quality of the assembly is excellent, typically between the first and third depending on the parameter used, and a significant improvement on previously published genomes for the species. We hope this assembly will play an important role in future conservation efforts and comparative studies of canid genomes.

Relative abundance of a mesocarnivore in a human-dominated, semi-arid rangeland in Namibia

Mesocarnivores fill important roles in ecological communities globally, but their distribution and abundance are often understudied. Many species have historically been regarded as vermin and subject to lethal control due to their role in livestock predation. Identifying the factors influencing mesocarnivore populations can help disentangle their relationship within ecological communities and inform conflict mitigation and conservation priorities. To help identify these factors, we used camera traps to study the community of medium and large mammals in four communal conservancies of northeastern Namibia covering the wet and dry seasons using 99 and 97 camera trap stations, respectively. We modelled black-backed jackal (Lupulella mesomelas) abundance using the robust Royle-Nichols model. Black-backed jackal were widespread, with a mean per site abundance of 2.01 (SD=0.66) in the wet season and 2.41 (SD=0.49) in the dry season. Black-backed jackal showed seasonally contrasting covariate associations, with lower abundance in areas with medium and large-sized wild prey during the wet season, and higher abundance in areas with more villages and close to African wild dog (Lycaon pictus) dens in the dry season. We identified localized hotspots of black-backed jackal abundance during the dry season, which may indicate that when resources are scarce, black-backed jackals rely on anthropogenic food sources despite an elevated risk for conflict, and on carcass remains from African wild dog kills. These findings highlight potential drivers of mesocarnivore abundance that would be obscured in a conventional occurrence modelling framework, and illustrate how local abundance may be influenced by seasonal variability, wild and anthropogenic food sources, and a likely facilitative relationship with a large carnivore. Further investigations in areas with more complex carnivore guilds and higher density of dominant predators are needed to understand black-backed jackal-African wild dog interactions and impacts on population dynamics.

Individual immune response to rabies vaccination in an African Wild Dog (Lycaon pictus) in Dubai Safari Park

Individual immune response to rabies vaccination in an African Wild Dog (Lycaon pictus) in Dubai Safari Park

A survey of nocturnality and risk for savanna chimpanzees at Assirik, Senegal.

Chimpanzees (Pan troglodytes) in Senegal may use nocturnality to mitigate hyperthermia risk in semi-arid environments but the degree of nocturnality for such chimpanzees also in sympatry with large carnivores remains uncertain. We compared diel activity among chimpanzees and their potential predators at Assirik in Niokolo-Koba National Park and contextualized these findings relative to other unit-groups in savanna landscapes. From 2015-2018, we generated a predator inventory using multi-modal methods and monitored the diel activity of chimpanzees and predators with camera traps [ N = 2092 camera trap (CT) days]. From 2015-2023, we also surveyed for evidence of predation during recce walks. Six potential nonhuman predators occur at Assirik, including lions (Panthera leo), leopards (Panthera pardus), spotted hyenas (Crocuta crocuta), African wild dogs (Lycaon pictus), Nile crocodiles (Crocodylus niloticus), and rock pythons (Python sebae). We documented one suspected case of a predator killing a chimpanzee. Nocturnality comprised 12.7% of CT events for chimpanzees and these events were more concentrated at twilight. Chimpanzees were more active during the day, predators were more active at night, and there was substantial temporal overlap among chimpanzees and potential predators during twilight intervals. Our findings support the hypothesis that savanna chimpanzees in Senegal are active at night in response to the extremely hot environment. We hypothesize that Assirik chimpanzees experience a tension between decreasing hyperthermia and increasing predation risk during nocturnality.

African wild dog (Lycaon pictus) masticatory apparatus and oral cavity morphology.

African wild dogs (Lycaon pictus) are unique among canids in their specialized hunting strategies and social organization. Unlike other, more omnivorous canids, L. pictus is a hypercarnivore that consumes almost exclusively meat, particularly prey larger than its body size, which it hunts through cooperative, exhaustive predation tactics. Its bite force is also among the highest reported for carnivorans. Here, we dissected an adult male L. pictus specimen and conducted diffusion iodine contrast-enhanced computed tomography (diceCT) scans to evaluate and describe its masticatory and oral cavity musculature. Muscles of mastication in L. pictus are separated by deep layers of thick intermuscular fascia and deep insertions. The superficial surface of m. masseter is entirely covered by an extremely thick masseteric fascia. Deep to m. masseter pars reflexa and superficialis are additional bellies, m. masseter pars profunda and zygomaticomandibularis. Musculus temporalis in L. pictus, divides into suprazygomatic, superficial, and deep bellies separated by a deep layer of thick intermuscular fascia, and it inserts along the entire rostral margin of the mandibular ramus. Musculus digastricus appears to comprise a single, large fusiform belly which appears to receive its innervation exclusively from CN V3 (nervus mandibularis, division of nervus trigeminus). Musculus pterygoideus medialis and lateralis are each composed of a single, deep belly. However, despite its great bite force, the jaw adductor muscle mass in L. pictus is not increased for its body size over other canid taxa. This finding suggests there are other architectural adaptations to hypercarnivory beyond increased muscle volume (e.g., pennation angle, greater strength, optimization of lever arms for mechanical advantage).

Effect of Rabies Booster Vaccination on Antibody Levels in African Wild Dogs (Lycaon pictus).

Rabies is a highly virulent viral disease that has been associated with large-scale population declines of the endangered African wild dog (Lycaon pictus). Rabies vaccination may be a valuable conservation tool in this species, but studies indicate that a single dose does not always confer protective immunity. We examined 47 serum samples from 22 captive African wild dogs (sampled opportunistically for other purposes) to assess whether serum antibody levels after vaccination correlated with the number of doses received and whether other factors affected outcomes. Results of the fluorescent antibody virus neutralization test showed that median antibody titers were 0.085 IU/mL prevaccination, 0.660 IU/mL after a single vaccination, and 22.150 IU/mL after a booster vaccination. Antibody titers above 0.5 IU/mL, internationally accepted as the threshold for seroconversion, were found in none of the samples taken prevaccination, 66.67% of samples taken after primary vaccination, and 90.90% of samples collected after booster vaccination. This study illustrates the probable protective benefit a rabies booster vaccination may provide in African wild dogs and serves as a basis for future research to improve vaccination protocols contributing to the conservation of this endangered species.

Long-term data reveal fitness costs of anthropogenic prey depletion for a subordinate competitor, the African wild dog (Lycaon pictus).

Within carnivore guilds, dominant competitors (e.g., lions, Panthera leo) are limited primarily by the density of prey, while subordinate competitors (e.g., African wild dogs, Lycaon pictus) have been limited by the density of dominant competitors. Historically, the fitness and population density of subordinate competitors have not been tightly linked to prey density. However, populations of large herbivores have declined substantially across sub-Saharan Africa due to human impacts, and where prey depletion is severe, fitness costs for competitive subordinates may begin to outweigh the benefits of competitive release. Using long-term intensive monitoring of African wild dogs in Zambia's Luangwa Valley Ecosystem (LVE), we tested the effects of prey depletion on survival and reproduction. We hypothesized that African wild dog fitness would be lower in prey-depleted areas, despite lower lion densities. Our study area included four contiguous regions that varied in protection level, prey density, and lion density. We fit Bayesian Cormack-Jolly-Seber and closed-capture models to estimate effects on survival and population density, and generalized linear models to estimate effects on reproductive success. We found that the LVE is a stronghold for African wild dogs, with an estimated median density of 4.0 individuals/100 km2. Despite this high density, survival and reproduction differed among regions, and both components of fitness were substantially reduced in the region with the lowest prey density. Anthropogenic prey depletion is becoming an important limiting factor for African wild dogs. If prey depletion (or any other form of habitat degradation) becomes severe enough that its fitness costs outweigh the benefits of competitive release, such changes can fundamentally alter the balance between limiting factors for competitively subordinate species.

Proactive cursorial and ambush predation risk avoidance in four African herbivore species.

Most herbivores must balance demands to meet nutritional requirements, maintain stable thermoregulation and avoid predation. Species-specific predator and prey characteristics determine the ability of prey to avoid predation and the ability of predators to maximize hunting success. Using GPS collar data from African wild dogs, lions, impala, tsessebes, wildebeest and zebra in the Okavango Delta, Botswana, we studied proactive predation risk avoidance by herbivores. We considered predator activity level in relation to prey movement, predator and prey habitat selection, and preferential use of areas by prey. We compared herbivore behaviour to lion and wild dog activity patterns and determined the effect of seasonal resource availability and prey body mass on anti-predator behaviour. Herbivore movement patterns were more strongly correlated with lion than wild dog activity. Habitat selection by predators was not activity level dependent and, while prey and predators differed to some extent in their habitat selection, there were also overlaps, probably caused by predators seeking habitats with high prey abundance. Areas favoured by lions were used by herbivores more when lions were less active, whereas wild dog activity level was not correlated with prey use. Prey body mass was not a strong predictor of the strength of proactive predation avoidance behaviour. Herbivores showed stronger anti-predator behaviours during the rainy season when resources were abundant. Reducing movement when top predators are most active and avoiding areas with a high likelihood of predator use during the same periods appear to be common strategies to minimize predation risk. Such valuable insights into predator-prey dynamics are only possible when using similar data from multiple sympatric species of predator and prey, an approach that should become more prevalent given the ongoing integration of technological methods into ecological studies.