Lycaon Pictus Research Articles

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 as well as 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 VGP 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, mat consists of only 166 contigs with an N50 of 39 Mbp. BUSCO analysis showed 95.4 % completeness based on Сarnivora conservative genes (carnivora_odb10). When compared to other available genomes from subtribe Canina, the quality of the assembly is excellent, typically between the 1st and 3rd 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.

Evaluation of trypsin-like immunoreactivity, pancreatic lipase immunoreactivity, cobalamin, and folate in zoo-housed African painted dogs (Lycaon pictus) at a North American zoological facility.

Assess markers for pancreatic function and gastrointestinal malabsorption in African painted dogs (Lycaon pictus), including canine trypsin-like immunoreactivity (cTLI), canine pancreatic lipase immunoreactivity (cPLI), cobalamin, and folate at one North American facility. 15 healthy African painted dogs held at one institution were sampled during routine health examinations. Blood was collected at routine health examinations, and serum was separated and stored until testing. Serum was analyzed for cTLI, cPLI, cobalamin, and folate. The results were evaluated for correlation to sex, age, and storage time of samples. All individuals had cTLI and folate levels below normal reference ranges for domestic dogs (< 5.0 µg/L and < 7.7 µg/L, respectively). Cobalamin values were within or above reported domestic dog ranges, and cPLI values were within range as well. No analytes were significantly influenced by sex or time in storage, while cTLI was positively correlated with age. cTLI and folate did not fall within normal domestic canid reference ranges in this population of healthy African painted dogs. Clinical interpretation of these values based on domestic canid recommendations would indicate clinical disease, which was not apparent in this population. Analytes for pancreatic function and malabsorption or gastrointestinal indicators, including cTLI, cPLI, and folate, in African painted dogs should be interpreted with caution when using domestic dog references ranges.

Predictions & perceptions: A social-ecological analysis of human-carnivore conflict in Botswana

Human-carnivore conflict in agrarian landscapes poses a significant threat to both large carnivore populations and human livelihoods. Conservation strategies aimed at mitigating conflict often rely primarily on ecological, landscape-scale factors. However, assessing the influence of microhabitat, as well as local variation in human perceptions, can offer valuable insights into the spatial patterns of human-carnivore conflict. The objectives of this study were to identify landscape predictors of livestock depredation risk, characterize microhabitat vegetation patterns at kill sites, and assess the spatial alignment between ecologically-predicted and human-perceived depredation risk. Through use of predation risk modeling, microhabitat pattern analysis, and participatory mapping exercises, we provide insight into the spatial patterns of livestock depredation risk from a multi-carnivore guild in an agrarian landscape located in the Makgadikgadi region of Botswana. We identified 170 depredation events and conducted 63 participatory mapping exercises across community lands situated between two wildlife protected areas. Results indicated anthropogenic landscape variables as the primary drivers of general depredation risk. Notably, distinct spatial patterns emerged between African lion (Panthera leo) and African wild dog (Lycaon pictus) depredation, underscoring the need for species-specific conservation strategies. Microhabitat analysis indicated a preference for lower vegetation cover within the multi-predator guild, suggesting livestock microhabitat risk-mitigation behaviors outweigh predator hunting strategies. While human perceptions generally aligned with ecologically predicted risk, identified divergences emphasize the importance of tailored conflict mitigation strategies to accommodate varying influences. Overall, the findings advocate for species-specific depredation risk analyses and the inclusion of human perceptions for a comprehensive spatial understanding of livestock depredation risk.

First insights into the spatio-temporal ecology of sympatric large carnivores in Niokolo-Koba National Park, Senegal

Abstract Large carnivores play a crucial role in their native ecosystems, but their populations are rapidly declining across the African continent. West Africa is no exception, with large protected areas often forming the last strongholds for these species. Little is known about the population status and ecology of large carnivores in the region, hampering the design and implementation of effective conservation strategies. We conducted a camera-trap survey during the dry season in Niokolo-Koba National Park, the largest terrestrial protected area in Senegal and the second largest in West Africa, to investigate the spatio-temporal ecology of the four large carnivores inhabiting the Park: the spotted hyaena Crocuta crocuta, leopard Panthera pardus, West African lion Panthera leo leo and African wild dog Lycaon pictus. Spotted hyaenas and leopards had the widest spatial distribution and highest probability of site use. Spotted hyaena site use was positively associated with leopard relative abundance index and negatively associated with normalized difference vegetation index, whereas only distance to the nearest road influenced leopard site use. Distance to the Gambian River was the most important covariate positively affecting site use by lions. African wild dog site use was negatively associated with the relative abundance indices of lions and leopards. Lions, spotted hyaenas and leopards showed strong overlap in their activity patterns. By providing new information on the ecology of large carnivores in West Africa, including where they range and which habitats are critical for their survival, our study will facilitate conservation planning. Our findings lay the foundations for future research to conserve these threatened species in West Africa effectively and to guide ranger patrol efforts, which are key for their long-term survival.

Dispersal and connectivity in increasingly extreme climatic conditions.

While climate change has been shown to impact several life-history traits of wild-living animal populations, little is known about its effects on dispersal and connectivity. Here, we capitalize on the highly variable flooding regime of the Okavango Delta to investigate the impacts of changing environmental conditions on the dispersal and connectivity of the endangered African wild dog (Lycaon pictus). Based on remote sensed flood extents observed over 20 years, we derive two extreme flood scenarios: a minimum and a maximum flood extent, representative of very dry and very wet environmental periods. These conditions are akin to those anticipated under increased climatic variability, as it is expected under climate change. Using a movement model parameterized with GPS data from dispersing individuals, we simulate 12,000 individual dispersal trajectories across the ecosystem under both scenarios and investigate patterns of connectivity. Across the entire ecosystem, surface water coverage during maximum flood extent reduces dispersal success (i.e., the propensity of individuals to disperse between adjacent subpopulations) by 12% and increases dispersal durations by 17%. Locally, however, dispersal success diminishes by as much as 78%. Depending on the flood extent, alternative dispersal corridors emerge, some of which in the immediate vicinity of human-dominated landscapes. Notably, under maximum flood extent, the number of dispersing trajectories moving into human-dominated landscapes decreases by 41% at the Okavango Delta's inflow, but increases by 126% at the Delta's distal end. This may drive the amplification of human-wildlife conflict. While predicting the impacts of climate change on environmental conditions on the ground remains challenging, our results highlight that environmental change may have significant consequences for dispersal patterns and connectivity, and ultimately, population viability. Acknowledging and anticipating such impacts will be key to effective conservation strategies and to preserve vital dispersal corridors in light of climate change and other human-related landscape alterations.

Comparative anatomy of the caudate nucleus in canids and felids: Associations with brain size, curvature, cross-sectional properties, and behavioral ecology.

The evolutionary history of canids and felids is marked by a deep time separation that has uniquely shaped their behavior and phenotype toward refined predatory abilities. The caudate nucleus is a subcortical brain structure associated with both motor control and cognitive, emotional, and executive functions. We used a combination of three-dimensional imaging, allometric scaling, and structural analyses to compare the size and shape characteristics of the caudate nucleus. The sample consisted of MRI scan data obtained from six canid species (Canis lupus lupus, Canis latrans, Chrysocyon brachyurus, Lycaon pictus, Vulpes vulpes, Vulpes zerda), two canid subspecies (Canis lupus familiaris, Canis lupus dingo), as well as three felids (Panthera tigris, Panthera uncia, Felis silvestris catus). Results revealed marked conservation in the scaling and shape attributes of the caudate nucleus across species, with only slight deviations. We hypothesize that observed differences in caudate nucleus size and structure for the domestic canids are reflective of enhanced cognitive and emotional pathways that possibly emerged during domestication.

Adaptations to sociality in the mimetic and auricular musculature of the African wild dog (Lycaon pictus).

The African wild dog (Lycaon pictus) is a highly social canid that engages in sophisticated, coordinated group hunting tactics to procure large game. It is one of the most effective hunters of the African savannah, due to its highly developed communication methods. It also has large, mobile ears which enhance its auditory capabilities while hunting and assist with thermoregulation. Recent research suggested that certain muscles of facial expression, particularly those involved with expressive eyebrow movement, evolved solely in domestic dogs (Canis familiaris) to facilitate communication with their human owners. However, it is unclear whether highly social wild canid species may also employ similar expressive eye communication. We performed detailed dissections of an adult male L. pictus to evaluate and describe its mimetic and auricular musculature. Overall, L. pictus has well-developed facial and ear muscles. Musculi levator anguli oculi medialis (LAOM) and retractor anguli oculi lateralis (RAOL), mimetic muscles of hypothesized importance in domestic dog-human non-verbal communication, are enlarged in L. pictus, comparable in size to those of domestic dogs, as is m. orbicularis oculi. This morphology suggests that ocular facial expressions contribute to within-pack communication in wild dogs and are not unique to domestic dogs. The auricular muscles of L. pictus are well-developed, supporting greater leverage and fine manipulation of its large, mobile ears. These muscular adaptations facilitate the highly social ecology of African wild dogs and challenge current interpretations about the unique nature of domestic dog facial expressions.

Size matters: Natural experiments suggest the dear enemy effect is moderated by pack size in African wild dogs.

Remote monitoring of communal marking sites, or latrines, provides a unique opportunity to observe undisturbed scent marking behaviour of African wild dogs (Lycaon pictus). We used remote camera trap observations in a natural experiment to test behavioural scent mark responses to rivals (either familiar neighbours or unfamiliar strangers), to determine whether wild dogs exhibit the "dear enemy" or "nasty neighbour" response. Given that larger groups of wild dogs represent a greater threat to smaller groups, including for established residents, we predicted that the overarching categories "dear enemy" vs. "nasty neighbour" may be confounded by varying social statuses that exists between individual dyads interacting. Using the number of overmarks as a metric, results revealed an interaction between sender and receiver group size irrespective of familiarity consistent with this prediction: in general, individuals from large resident packs overmarked large groups more than they overmarked smaller groups, whereas individuals from smaller packs avoided overmarking larger groups, possibly to avoid detection. Monitoring a natural system highlights variables such as pack size that may be either overlooked or controlled during scent presentation experiments, influencing our ability to gain insights into the factors determining territorial responses to rivals.