No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Hunting Behavior and Social Ecology of African Wild Dogs
Abstract
African wild dogs (Lycaon pictus) are cooperatively breeding highly social hyper-carnivores. The basic social unit is the pack, which in its simplest form revolves around an unrelated dominant pair and their offspring. Group cohesion is central to pack social dynamics, with litters reared collectively, decisions to move made semi-democratically, and hunting occurring collectively—if not collaboratively—over home ranges of several hundred square kilometers. These large ranges coupled with strong Allee effects make this species extinction prone, and urgent conservation actions require a detailed fundamental understanding of the complex inter-pack and inter-individual dynamics that make up the social fabric of this iconic species. In this chapter, we provide an overview of African wild dog social adaptations, particularly about hunting. We present a conceptual framework illustrating the common phases and transitions of a typical hunt, populating descriptions of these phases with examples from different regions and environments within the extant range. Finally, we consider the direct and indirect challenges faced by African wild dogs as they navigate the Anthropocene, including climate impacts and the need to consider complex social dynamics within population management approaches.
... Collars dropped off using a programmable release mechanism (Telonics CR-7B) after 31 d and were collected. Because wild dog packs move and hunt in a highly cohesive manner (40,45,48), we tagged a single individual in each sampled pack. We tagged packs that used areas spanning the highest and lowest prey densities within the two ecosystems (see Prey Biomass Distributions and Lion Utilization Distributions, below). ...
... Specifically, we identified kills as events within 375 s of a hunting effort, with periods >18 s with a pitch angle (mean over 5 s) < −25°, and VeDBA (mean over 2 s) >0.02 g and VeDBA (mean over 5 s) <0.15 g, and acceleration in the heave axis (over 0.5 s) >0.7 g. We developed these Boolean rules to identify hunting efforts and kills from DD data using first principles (79), by consideration of the patterns that would be produced by the hunting and feeding behavior of wild dogs (40,43,45,46,48,80). We validated both rules by comparing the hunts and kills that they identified with data from direct observation of three DD-tagged packs in Kafue, using data from 47 d (79). ...
... Many species live in groups but forage independently ( 95 ), but wild dogs virtually never move or hunt alone. The enthusiastic social rally that precedes periods of activity is one of the most distinctive features of wild dogs' behavior, and its most obvious function is to coordinate the movement and hunting that almost invariably follows ( 45 ). Even when hunting small animals in areas affected by prey depletion, wild dogs always hunted in highly cohesive and coordinated groups, in both ecosystems. ...
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.
... In some group-living species, group members provide and share food with other group members (Jaeggi & Gurven, 2013;Silk et al., 2013;Burkart et al., 2014;Carter & Wilkinson, 2015;Dale et al., 2017). Such food provisioning is frequent in cooperatively breeding species in which non-parents take care of immatures, e.g., meerkats (Suricata suricatta) (Brotherton et al., 2001), acorn woodpeckers (Melanerpes formicivorus) (Koening & Walters, 2016), common marmosets (Callithrix jacchus) (Burkart et al., 2007), and African painted dogs (Lycaon pictus) (Jordan et al., 2022(Jordan et al., , 2023. In contrast to spontaneous food provisioning to immatures, food sharing among adults often involves disagreement between owners and beggars and is mediated by social negotiation. ...
... The cooperatively breeding African painted dog exhibits a variety of cooperative behaviours, such as alloparental care, hunting and territorial defence (Creel & Creel, 2002;Jordan et al., 2023). A pack consists of a few to approximately 30 reproductive mature members with generally a single reproductive alpha pair (Creel & Creel, 2002). ...
... Dominance and age significantly influence feeding priority, wherein the dominance of the breeding pair helps mediate their offspring's access to food, ensuring survival and growth (Jordan et al., 2022). Such altruistic behaviour is seemingly an exception among mammals (Jordan et al., 2022(Jordan et al., , 2023. Although it is unclear whether and to what extent adult individuals compete and negotiate for food, several observations suggest that food competition among African painted dogs is rarely severe or highly costly. ...
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.
... This ability is also observed when dogs hunt. Hunting in canids is based on the transfer of information between individuals during group movements [59,60] and as observed in African Wild Dogs, it implies that individuals focus their attention on a single prey and relate to one another in space and time [61,62]. Dogs, like other canids, are able to identify Figure 1. ...
... This ability is also observed when dogs hunt. Hunting in canids is based on the transfer of information between individuals during group movements [59,60] and as observed in African Wild Dogs, it implies that individuals focus their attention on a single prey and relate to one another in space and time [61,62]. Dogs, like other canids, are able to identify Animals 2024, 14, 548 5 of 18 the position and activity of their partners in order to hunt cooperatively. ...
Dogs’ behavioural synchronisation with humans is of growing scientific interest. However, studies lack a comprehensive exploration of the neurocognitive foundations of this social cognitive ability. Drawing parallels from the mechanisms underlying behavioural synchronisation in humans, specifically motor resonance and the recruitment of mirror neurons, we hypothesise that dogs’ behavioural synchronisation with humans is underpinned by a similar mechanism, namely interspecific motor resonance. Based on a literature review, we argue that dogs possess the prerequisites for motor resonance, and we suggest that interspecific behavioural synchronisation relies on the activation of both human and canine mirror neurons. Furthermore, interspecific behavioural studies highlight certain characteristics of motor resonance, including motor contagion and its social modulators. While these findings strongly suggest the potential existence of interspecific motor resonance, direct proof remains to be established. Our analysis thus paves the way for future research to confirm the existence of interspecific motor resonance as the neurocognitive foundation for interspecific behavioural synchronisation. Unravelling the neurocognitive mechanisms underlying this behavioural adjustment holds profound implications for understanding the evolutionary dynamics of dogs alongside humans and improving the day-to-day management of dog–human interactions.
... The African wild dog (Lycaon pictus) is one such species of canid that exhibits complex social behavior that may in turn affect the cranial anatomy, particularly myology. Lycaon pictus is typically considered the most social canid species (Fox, 1975;Jordan et al., 2023;Kat et al., 1996), living in large, highly integrated, and cooperative packs. They spend most of their time in close association with pack members, on whom they rely heavily (McCreery, 2000). ...
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.
... It enables predators to capture larger prey that would be challenging for a single predator to tackle alone. Group hunting also reduces chasing distances, allowing for faster and easier access to food resources [9]. Additionally, cooperative hunting helps prevent other predators from usurping the captured carcass [10]. ...
In this study, the specific focus is on investigating the influence of environmental fluctuations on a predator–prey system featuring a generalist predator and hunting cooperation. To incorporate environmental fluctuation into the predator–prey model, we introduce perturbations in the birth rate of prey and the death rate of predator density using Gaussian white noise. We conducted a comprehensive analysis of parameter sensitivity within our system and delved into the significance of the initial states of the species. Altering the initial states of the population have been shown to exert a profound influence on both the dynamics of the system and the long-term sustainability of the species. Our study has uncovered the degree of sensitivity exhibited by the system’s parameters and has identified distinct types of sensitivity that manifest under different initial conditions, offering a novel perspective on the dynamics of the system. By simulating the stochastic system, we analyze the fluctuations in the populations within the ecosystem, considering the influence of stochastic perturbations. Our research demonstrates that prey growth rate, carrying capacity, and prey handling time significantly affect the predator species. Initial conditions for both species are vital for ecosystem persistence, especially with low initial prey density leading to predator extinction risk. Additionally, the higher noise levels lead to species extinction, while lower levels support coexistence. Our study on hunting cooperation and environmental fluctuations enhances our understanding of complex ecological systems. The incorporation of stochasticity provides valuable insights into the behavior of the predator and prey populations, highlighting the importance of considering both biological interactions and environmental variability in ecological studies.
Social mammalian predators typically forage in groups and maintain mostly consistent membership. Within the social unit, there could be a hierarchy for allocating resources and predators may benefit from hunting together than alone. An intriguing question that this book poses is whether the benefits of cooperative hunting warrant group living or whether benefits of group living predispose animals to hunt communally. Consolidation of similar species or taxa-specific studies in a comparative context can help elucidate some of the ways different researchers are approaching questions on cooperative predation and sociality. Each chapter is dedicated to a social mammalian carnivore hunting mammalian prey. In total, we provide representative examples from five terrestrial and one marine species. We have been intentionally selective in our choices to allow a holistic synthesis of knowledge and better illustration of social unit characteristics and predation strategies. We learn that the lives of these predators are shaped by resource variability, lateral and vertical information transfer, human forces, and intrinsic life history, social, and behavioral traits. We consider impacts of human and environmental change on the social habits of these predators, specifically the potential disruption of social learning when the social structure is fragmented. As an overarching goal, the book hopes to offer insights on the value of protecting social predators to maintain ecosystem resilience.
Bigg’s (Transient) killer whales (Orcinus orca) display incredible cooperative hunting techniques and a complex social organization. We describe the predation behavior of Bigg’s killer whales in Monterey Bay, California, over a 30-year period. These killer whales are marine mammal foraging specialists, with aspects of their occurrence, habitat use, association patterns, hunting strategies, and communication calls influenced by this ecological specialization. This population encompasses at least 193 individuals and 44 different matrilines. Bigg’s killer whales off Monterey, California predate 12 different marine mammal species. Within this population, there are six key matriarchs that have played a significant role over the past three decades in 85% of gray whale calf (Eschrichtius robustus) predation events—an important prey in spring. Some killer whales gather in large groups during gray whale hunting season, where they jointly participate in attacks and engage in multi-group socializing for several days. When hunting smaller prey such as seals, sea lions, dolphins, and porpoises, they generally travel in separate matrilines composed of a mother and her non-dispersed offspring. Based on extensive observations, we believe that their prey-specific hunting techniques and their communication calls are likely transferred to subsequent generations through social learning, primarily through imitation. This culturally transmitted information results in sustained knowledge and enhancement of hunting techniques in successive generations. Despite apex predator status and lack of natural predators, Bigg’s killer whale populations are vulnerable to the effects of climate change through potential changes in their marine mammal prey abundance and distribution, and the effects of persistent contaminants such as DDTs and PCBs that could negatively affect their reproductive success and immune system. The current chapter is a descriptive summary of the social dynamics and hunting prowess of mammal hunting killer whales in Monterey Bay. Future investigations are necessary to analyze observed patterns on hunting success, group size dynamics, predation risk effects, and social association patterns.
What sets apart social predators from other predators is their ability to hunt together and successfully attack prey larger than themselves, defend territories and offspring, and transmit information to successive generations. Group hunting may not be the norm and ecological pressures as well as the need to survive and reproduce require them to be nimble and switch to solitary hunts while maintaining diverse social groupings. Participation and allegiance to specific social groups may provide these social predators to evolve specialized group hunting techniques, protect young, and satisfy foraging and reproductive demands. Additionally, social membership may bestow group members with the capacity to adapt and be resilient to environmental disturbance through social learning. In this chapter, we summarize key findings and present commonalities and differences in the social dynamics and hunting strategies of spotted hyena, African & Asiatic lions, gray wolves, killer whales, and African wild dogs. For most terrestrial species, group hunting may at least in part be an artifact of gregariousness due to reproductive strategies—which are probably best established for African lions among our focal species, whereas for mammal-hunting killer whales, we speculate the opposite, wherein sociality is a by-product of a cooperative hunting lifestyle. Above all as scientists in the field, we must be persistent in conducting or contributing data toward comparative studies of social predators across marine and terrestrial environments.
Scent marks deposited as semiochemical signals are a primary mode of communication for a broad range of mammal species. Such scent signals are often deposited at specific, frequently visited marking sites called latrines. Despite descriptions of widespread latrine use by numerous mammal species, detailed understanding of site visit rates and latrine function is lacking. Here we report for the first time a quantitative assessment of scent-marking behaviours that represent interpack olfactory communication by African wild dogs, Lycaon pictus, at latrines visited by multiple resident neighbouring packs, hereafter called a ‘shared marking site’ (SMS). We show that multiple packs visited specific SMSs frequently and regularly throughout the year, with a notable decrease in visits during the 3-month denning season coinciding with a contraction in range size. In addition to resident neighbouring packs, dispersing individuals visited and scent-marked at SMSs, suggesting that latrines function at least in part as sites communicating information about residence and possibly reproductive status. Further detailed investigation of the relevance of latrine use to territorial behaviour, ranging, habitat use and dispersal in this species is required, particularly as it may have direct applied conservation implications for this wide-ranging but territorial endangered species.
Understanding the use of space by endangered African wild dogs (Lycaon pictus) can contribute to their conservation because persecution by livestock farmers is a major cause of mortality when wild dogs range outside protected wildlife areas. Scent-marking is likely to be a key mechanism by which African wild dog packs organise their mutual use of space, and here, we report the discovery that African wild dog packs repeatedly shared a scent-marking latrine. We present the first systematic records of scent communication between packs of African wild dogs. Camera trapping for 13 months recorded four wild dog packs in northern Botswana repeatedly scent-marking with urine and faeces at a latrine where two dirt roads crossed a large game trail, in the overlap zone of two of the packs’ home ranges. This site was visited by wild dogs at a mean interval of 12.2 days, with a mean of 10.3 days between consecutive visits by different packs, and a mean of 28.7 days between consecutive visits by the same pack. Dominant dogs scent-marked every time they visited this site for a minute or longer. Sniffing and countermarking of scent-marks from previous visits showed that this shared marking site acted as a bulletin board, with 12 exchanges of information between packs over a period of 13 months.
Significance statement
African wild dogs are endangered large carnivores, whose populations suffer continual attrition from lethal conflict with livestock owners. Deterring wild dogs from leaving protected wildlife areas will reduce this conflict-related mortality. All terrestrial mammals mark their home ranges with scent, and using artificial scent-marks to simulate African wild dog home range boundaries along protected area borders has the potential to reduce conflict killings by deterring the dogs from leaving the protected areas. Our discovery of multiple African wild dog packs scent-marking at a persistent, shared latrine, where scent-marking depended on sex and social status, is a breakthrough in our understanding of inter-pack communication in this endangered species and a key step towards developing artificial home range boundary markers that will deter them from leaving protected wildlife areas.
Patterns of food sharing in collectively hunting species are likely to influence social dynamics and evolution. Despite this, little is known about competition within social groups at carcasses and other food sources, making the social drivers and implications of food sharing difficult to assess. We quantified carcass access and feeding behavior in free-ranging African wild dogs, Lycaon pictus, at natural kill sites, confirming and quantifying previous descriptions of a youngest-feed-first system. Using data on feeding duration and latency to feed, we confirm that the position in the feeding queue (PFQ) runs from youngest to oldest, except the dominant pair, which generally feed after the pups. We found some evidence that older subdominants were more likely to participate in kills, perhaps because they may only gain access to carcasses at the most profitable early stages of consumption if they make the kill themselves. These dogs were no more likely to initiate hunts or sustain probable hunting-related injuries than were younger dogs with better access. We suggest that allowing younger animals uncontested access to food they have not caught themselves may be an extension of helping behavior prioritizing those least able to catch food themselves, and that this system may provide possible anti-kleptoparasitism benefits. Our results contribute to the discussion on the functions and importance of food sharing more broadly.
Significance statement
Food-sharing by group-hunting animals is not well understood, but may affect many aspects of their life, including how much an individual contributes to hunting, and whether they remain in the group or disperse elsewhere. To better understand food-sharing and its implications, we recorded social aspects of feeding behavior in African wild dogs in Botswana. We confirmed an unusual system where the youngest generally feed first and found that dogs lower down the feeding queue were more likely to participate in kills, but were not more likely to initiate hunts or get injured. We speculate that allowing group members access to food that they have not caught themselves may incentivize them to attend kill sites, and thereby reduce the risk of the pack being ambushed by their competitors there or losing the kill to scavengers.
Many species rear offspring in fixed sites, returning frequently to provision them, and the selection of these sites is a critical decision in the life cycle, as they may in some instances increase susceptibility to predators. African wild dogs are a groupliving large carnivore that rear their offspring in fixed sites, provisioning dependent pups in dens for 3 months post-birth. Where possible, African wild dogs select den sites in rocky terrain, and it is hypothesised that this is because lions, their main predators, generally avoid this habitat. In the Okavango Delta, Botswana, there is a lack of rocky terrain, providing an opportunity to assess whether lions drive den site selection. GPS collar data from 7 impala and 4 lions revealed that both species prefer to reside in grassland and mixed woodland habitats, demonstrating that these are high risk/reward areas for African wild dogs. Using GPS collar data from 16 African wild dog packs over 8 years, our study characterised 116 African wild dog den sites identified in the field. Packs showed a preference for denning in mopane woodland, which lions avoid, and packs commuted further from the den each day as the den’s distance to grassland and mixed woodland increased, suggesting a preference for hunting in this habitat. Our results suggest that African wild dogs trade-off the costs of commuting and predation risk, such that longer commuting costs confer increased safety.
Significance statement
Species which utilise dens, nests, or other fixed sites to rear offspring must balance the need to protect their young from predators with the need to acquire resources for themselves and their young. The selection of den sites is expected to be of considerable importance to enable the animal to meet these two requirements and successfully raise young. Our study of African wild dogs indicates that they select dens in resource-scarce areas which are likely to minimise interactions with their main predator, lions. This increases the distance to prey-rich areas and therefore the cost of hunting. Availability of appropriate habitat for both hunting and denning is therefore important when considering landscapes appropriate for African wild dog conservation, energetic constraints of breeding, and home-range indices.
• The impacts of high ambient temperatures on mortality in humans and domestic animals are well-understood. However much less is known about how hot weather affects mortality in wild animals. High ambient temperatures have been associated with African wild dog Lycaon pictus pup mortality, suggesting that high temperatures might also be linked to high adult mortality.
• We analyzed mortality patterns in African wild dogs radio-collared in Kenya (0°N), Botswana (20°S), and Zimbabwe (20°S), to examine whether ambient temperature was associated with adult mortality.
• We found that high ambient temperatures were associated with increased adult wild dog mortality at the Kenya site, and there was some evidence for temperature associations with mortality at the Botswana and Zimbabwe sites.
• At the Kenya study site, which had the highest human impact, high ambient temperatures were associated with increased risks of wild dogs being killed by people, and by domestic dog diseases. In contrast, temperature was not associated with the risk of snare-related mortality at the Zimbabwe site, which had the second-highest human impact. Causes of death varied markedly between sites.
• Pack size was positively associated with survival at all three sites.
• These findings suggest that while climate change may not lead to new causes of mortality, rising temperatures may exacerbate existing anthropogenic threats to this endangered species, with implications for conservation. This evidence suggests that temperature-related mortality, including interactions between temperature and other anthropogenic threats, should be investigated in a greater number of species to understand and mitigate likely impacts of climate change.
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.
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.
Masenga E, Hasan SN, Japhet K. 2018. Abundance, distribution, and conservation threats of African wild dog (Lycaon pictus) in the Loliondo Game Controlled Area, Tanzania. Asian J For 2: 31-41. Assessment of abundance, distribution, and conservation threats to African wild dogs was conducted in Loliondo Game Controlled Area (LGCA), northern Tanzania. Specifically, the study focused on determining population size and structure, spatial distribution, attitudes of local people towards wild dogs and wild dog conservation and threats impacting the species. Semi-structured interviews, diurnal random searches, internal and external examinations of wild dogs carcasses examined, and night transect surveys were employed. Eight packs with a total of 132 recognized individuals at an average pack size of 16.50 ± SD 7.50 individuals were recorded. Pack sizes 3 individuals were reported to be sighted mostly and of all respondents (n= 210), only 26% were able to recognize wild dog sexes. The density of both known and unknown wild dogs was 0.19 animals/km2, higher compared to other carnivores. In terms of distribution, most of the packs were concentrated in the northern part as compared to the central and southern parts of LGCA. The species was observed to occur most in woodland type of vegetation. Interestingly, 55.30% of respondents showed a positive attitude towards wild dogs and wild dog conservation despite that 52.90% of respondents dismissed lack of any conservation action or strategy in place towards conserving the species. However, poisoning and Canine Distemper Virus were identified as the main threats. Therefore, conserving African wild dogs in LGCA requires mult-approach conservation efforts (i.e. awareness rising to community, fitting radio telemetry to the dogs and threats management interventions) due to nature of the species.
Large carnivores have experienced considerable range contraction, increasing the importance of movement across human-altered landscapes between small, isolated populations. African wild dogs (Lycaon pictus) are exceptionally wide-ranging, and recolonization is an important element of their persistence at broad scales. The competition-movement-connection hypothesis suggests that adaptations to move through areas that are unfavorable due to dominant competitors might promote the ability of subordinate competitors (like wild dogs) to move through areas that are unfavorable due to humans. Here, we used hidden Markov models to test how wild dog movements were affected by the Human Footprint Index in areas inside and outside of South Luangwa National Park. Movements were faster and more directed when outside the National Park, but slowed where the human footprint was stronger. Our results can be directly and quantitatively applied to connectivity planning, and we use them to identify ways to better understand differences between species in recent loss of connectivity.
Reliable estimates of birth, death, emigration and immigration rates are fundamental to understanding and predicting the dynamics of wild populations and, consequently, inform appropriate management actions. However, when individuals disappear from a focal population, inference on their fate is often challenging.
Here we used 30 years of individual‐based mark–recapture data from a population of free‐ranging African wild dogs Lycaon pictus in Botswana and a suite of individual, social and environmental predictors to investigate factors affecting the decision to emigrate from the pack. We subsequently used this information to assign an emigration probability to those individuals that were no longer sighted within their pack (i.e. missing individuals).
Natal dispersal (i.e. emigration from the natal pack) showed seasonal patterns with female dispersal peaking prior to the mating season and male dispersal peaking at the beginning of the wet season. For both sexes, natal dispersal rate increased in the absence of unrelated individuals of the opposite sex in the pack. Male natal dispersal decreased with increasing number of pups in the pack and increased in larger packs. Female natal dispersal decreased with increasing number of pups in larger packs, but increased with increasing number of pups in smaller packs. Individuals of both sexes were less likely to exhibit secondary dispersal (i.e. emigration from a pack other than the natal pack) if they were dominant and if many pups were present in the pack.
Our models predicted that 18% and 25% of missing females and males, respectively, had likely dispersed from the natal pack, rather than having died. A misclassification of this order of magnitude between dispersal and mortality can have far‐reaching consequences in the evaluation and prediction of population dynamics and persistence, and potentially mislead conservation actions.
Our study showed that the decision to disperse is context‐dependent and that the effect of individual, social and environmental predictors differs between males and females and between natal and secondary dispersal related to different direct and indirect fitness consequences. Furthermore, we demonstrated how a thorough understanding of the proximate causes of dispersal can be used to assign a dispersal probability to missing individuals. Knowledge of causes of dispersal can then be used within an integrated framework to more reliably estimate mortality rates.
African wild dogs have declined in numbers over the past years. Their persistence is largely dependent on effective conservation and management strategies. In Zimbabwe, although the population is threatened, packs in Mana Pools National Park (MNP) are characterized by larger packs compared to those in Hwange National Park (HNP). The study aims at comparing the pack sizes, pup production, pup survival, recruitment, pack longevity, and sex ratios between the two populations. The life histories of 8 packs in HNP and 7 packs in MNP that existed in the period 2007 – 2012 were followed using, photographs, direct observation, and survey forms. From which the data on pack sizes, pup production and pup survival, recruitment, pack longevity, and sex ratios were determined. Results show that there were significant differences in pack sizes, with MNP packs being bigger relative to those in HNP (two way ANOVA, F (1,5) = 32.92, p < 0.001). In all reproduction parameters (pup production, pup survival, and recruitment) HNP had significantly lower values compared to MNP (p < 0.001). There were no significant differences in pack longevity between the two populations (Mann-Whitney U = 12.5, p = 0.075). Sex ratios did not significantly differ between the two populations (Chi-square χ2 = 0.85; 1 df; p = 0.36). This shows that HNP packs are very much at risk of local extirpation due to low pack sizes, which has implications in their ability to successfully reproduce. Conservation efforts should thus be intensified in protecting the existing packs in HNP from further loss of individuals due to snaring and road kills, which have been shown to be the major causes of mortality. There is also need for further research on why packs in HNP are failing to reproduce, the causes of pup mortality, and the likely impacts of other keystone species such as elephants on African wild dogs.
Successful conservation of species that roam and disperse over large areas requires detailed understanding of their movement patterns and connectivity between subpopulations. But empirical information on movement, space use, and connectivity is lacking for many species, and data acquisition is often hindered when study animals cross international borders. The African wild dog (Lycaon pictus) exemplifies such species that require vast undisturbed areas to support viable, self‐sustaining populations. To study wild dog dispersal and investigate potential barriers to movements and causes of mortality during dispersal, between 2016 and 2019 we followed the fate of 16 dispersing coalitions (i.e., same‐sex group of ≥1 dispersing African wild dogs) in northern Botswana through global positioning system (GPS)‐satellite telemetry. Dispersing wild dogs covered ≤54 km in 24 hours and traveled 150 km to Namibia and 360 km to Zimbabwe within 10 days. Wild dogs were little hindered in their movements by natural landscape features, whereas medium to densely human‐populated landscapes represented obstacles to dispersal. Human‐caused mortality was responsible for >90% of the recorded deaths. Our results suggest that a holistic approach to the management and conservation of highly mobile species is necessary to develop effective research and evidence‐based conservation programs across transfrontier protected areas, including the need for coordinated research efforts through collaboration between national and international conservation authorities. © 2020 The Wildlife Society.
South Africa is one of only seven countries with a viable population of African wild dogs (Lycaon pictus). The national population in 2017 was 372 adults and yearlings and comprised three subpopulations: 1) Kruger National Park (Kruger), 2) an intensively managed metapopulation established through reintroductions into isolated, fenced reserves, and 3) a free-roaming population that occurs naturally outside protected areas. We assessed the long-term (four wild dog generations, ∼20 years) trends in population size and growth rate within each of these three subpopulations. We found that Kruger supports a substantial population, which has declined over time. The metapopulation is the only subpopulation that has increased significantly over time (both in population size and number of packs), likely due to intensive conservation efforts and the reintroduction of wild dogs into 15 additional reserves since 1998. The free-roaming subpopulation has remained small but stable, even though the number of packs has declined due to anthropogenic threats. The overall national population has remained stable even though the number of packs has increased. Kruger has consistently supported the highest proportion of the national population over the last two decades. However, the contribution of the metapopulation has increased significantly over time. It is clear that despite differences in survey effort among the three subpopulations, South Africa has a small (∼500) but stable population of wild dogs, with the metapopulation contribution becoming increasingly important. The circumstances in the country necessitate, and demonstrate the benefit of, intensive, adaptive management for the national population of wild dogs. While this assessment provides baseline information for the three subpopulations, wild dog conservation in South Africa would benefit greatly from equal survey effort and standardized methods to accurately assess long-term population trends.
There are several hypotheses that could explain territory size in mammals, including the resource dispersion hypothesis (RDH), the intruder pressure hypothesis (IPH), and the intraguild predation hypothesis (IGPH). In this study, we tested predictions of these three hypotheses regarding territories of 19 packs of endangered African wild dogs (Lycaon pictus) over 2 years in the Kruger National Park, South Africa. If territory size was supported by the RDH, then we would observe (1) wild dog territories would be larger when resource patches were more dispersed, (2) pack sizes would be larger when resource patches were rich, and (3) pack size would not affect territory size. If supported by the IPH, then we would observe (4) larger territories would experience less intrusions, and (5) there would be an increase in territory overlap in areas of low resource dispersion. Finally, if supported by the IGPH, we would observe (6) territories would be larger in areas of higher lion (Panthera leo) density, as evidence of a spatial avoidance strategy. We found that the IGPH was fully supported (6), the IPH half supported (5), and the RDH partially supported (1 and 3), where we found spatial partitioning of wild dogs with lions, potentially mediated by resources and territory overlap with conspecifics. Ultimately, our results show that subordinate carnivores must balance a trade-off between dominant interspecific competitors and conspecifics to successfully coexist in areas with dominant carnivores.
Cooperative behaviour can have profound effects on demography. In many cooperative species, components of fitness (e.g. survival, reproductive success) are diminished in smaller social groups. These effects (termed group‐level component Allee effects) may lead smaller groups to grow relatively slowly or fail to persist (termed group‐level demographic Allee effects).
If these group‐level effects were to propagate to the population level, small populations would grow slowly or decline to extinction (termed population‐level demographic Allee effects). However, empirical studies have revealed little evidence of such population‐level effects.
Theoretical studies suggest that dispersal behaviour could either cause or prevent the propagation of group‐level Allee effects to the population level. We therefore characterized within‐ and between‐pack dynamics in a population of African wild dogs (Lycaon pictus) to test these contrasting model predictions.
Larger wild dog packs produced more pups, and their members experienced higher survival than those in smaller packs. Nevertheless, larger packs grew more slowly than smaller packs, because natal adults dispersed away from them. Most packs either died out in whole‐pack death events or broke up when their founders died, irrespective of pack size. Overall, packs showed negative density dependence rather than group‐level demographic Allee effects.
Larger packs produced more, but not larger, dispersal groups and hence generated more, but not larger, new packs. Larger packs thus contributed more than smaller packs to the number of packs in the population, but their large size did not propagate to their daughter packs. This pattern helps to explain the absence of population‐level Allee effects in this species.
Dispersal behaviour, itself driven by natural selection on individual reproductive strategies, played a pivotal role in population dynamics, leading to the formation of new packs and limiting the size of established packs. Understanding dispersal processes is likely to be important to understanding the population dynamics of other cooperatively breeding species.
Understanding how reproductive timing has evolved to reflect climatic conditions is increasingly important as the climate changes, influencing species persistence and ecosystem dynamics. Among endotherms, seasonal reproduction is often linked to natural selection for reproducing when biotic conditions (e.g. food availability) are most favourable. In contrast, we present evidence that direct effects of an abiotic factor have selected for seasonal reproduction in a tropical mammal. We have shown previously that the African wild dog (Lycaon pictus), a diurnally active coursing predator, has lower reproductive success at high ambient temperatures, when its hunting activity is constrained. We therefore hypothesized that natural selection would favour reproduction during cool weather conditions, in locations where such conditions occur predictably. We show that, as predicted, wild dogs reproduce seasonally at latitudes from 7 to 25°S, such that their pup‐rearing periods coincide with the coolest (but not the driest) weeks of the year. Wild dog reproduction is aseasonal at latitudes ≤2°. As the climate warms, some temperate‐zone species have tracked optimal conditions through altered phenology. However, in seasonally breeding wild dog populations, any alteration in phenology would require breeding in hotter weather, probably reducing reproductive success. This endangered species may thus have a limited ability to adapt to climate change. Seasonal reproduction might be a trait indicating climate change vulnerability among tropical species. Many mammals reproduce at the time of year when food is most abundant. In contrast, we show that birth timing in African wild dogs allows pups to be reared during the coolest weeks of the year, when hunting is less constrained by high ambient temperatures. Sensitivity to hot weather may signal vulnerability to climate change for this endangered species.
Understanding factors that affect the reproductive output and growth of a population of endangered carnivores is key to providing
information for their effective conservation. Here, we assessed patterns in reproduction for a small population of endangered African
wild dogs (Lycaon pictus) over 90 pack years. We tested how availability of prey, pack size, pack density, rainfall, temperature and
female age affected the age of first litter, litter size and pup survival.We found that females bred youngerwhen pack density, availability
of prey and pack size were large.We also found that fecundity increased significantly with age while the population was male biased
only for 1-, 2- and 4-year olds. Larger litters were produced by larger packs, suggesting strong reproductive benefits of grouping related
to cooperative hunting and food provisioning for helpers and alpha females.We also found an interaction between breeding female age
and pack size where older females in large packs raised a high proportion of pups. Additionally, large litters and large packs were
important for raising a greater number of pups to 6 and 12 months, respectively, suggesting that while litter size is important for pup
survival, the benefits of a large pack are only realised when pups are older andmobile with the pack. Collectively, these results illustrate
the novel finding that prey availability is critically important in initiating reproduction inwild dogs and that the number of non-breeding
helpers, female age and litter size is essential to pup survival.
Social integration is an important factor when reintroducing group-living species, but examples of the formation of social groups before reintroduction are largely lacking. African wild dogs Lycaon pictus are endangered, and reintroductions have become a routine part of range expansion in South Africa. Wild dogs form packs that are essential to their reproduction and survival, and artificial pack formation is often required before reintroduction. We examined the proximate (i.e. social integration) and ultimate (i.e. reproduction) success of 43 artificial pack formation attempts in the South African managed metapopulation, between 1995 and 2018. The top (and dominant) model for proximate success included an interaction between total group size and an initial separation fence. Larger groups took longer to integrate, irrespective of initial separation, whereas smaller groups brought together immediately integrated faster than those that were initially separated. The top models for ultimate success included an interaction between the proportion of males and number of days spent in the pre-release enclosure, the total number of days in the enclosure and an interaction between the proportion of captive-sourced individuals and the total number of days in the enclosure. Ultimate success increased when packs spent less time in the enclosure , especially if those packs had a low proportion of males (i.e. female biased) or included >25% captive-sourced individuals. Neither the size of the artificially created pack nor the season in which the pack was released affected ultimate success. The success of social integration and reproductive success of artificially formed packs in this study was higher than for natural pack formations. We provide guidelines for optimizing future artificial pack formation in wild dogs for reintroduction success. Our results serve as an example of the practical importance of social behavior in successfully implementing conservation measures for group-living species.
Climate change is widely accepted to be one of the greatest threats to species globally. Identifying the species most at risk is, therefore, a conservation priority. Some species have the capacity to adapt to rising temperatures through changing their phenology, behavior, distribution, or physiology, and, therefore, may be more likely to persist under rising temperatures. Recent findings suggest that the African wild dog Lycaon pictus may be impacted by climate change, since reproductive success is consistently lower when pup-rearing coincides with periods of high ambient temperature. We used GPS collars, combined with generalized linear mixed-effects models, to assess wild dogs' potential to adapt to high ambient temperatures through flexible timing of hunting behavior. On days with higher maximum temperatures, wild dogs showed lower daytime activity and greater nocturnal activity, although nocturnal activity did not fully balance the decrease in daytime activity, particularly during the denning period. Increases in nocturnal activity were confined mainly to moonlit nights, and were seldom observed when packs were raising pups. Our findings suggest that nocturnal activity helps this cursorial hunter to cope with high daytime temperatures. However, wild dogs appear not to use this coping strategy when they are raising pups, suggesting that their resource needs may not be fulfilled during the pup-rearing period. Given that moonlight availability-which will not change as the climate changes-constrains wild dogs' nocturnal activity, the species may have insufficient behavioral plasticity to mitigate increasing diurnal temperatures. These findings raise concerns about climate change impacts on this endangered species, and highlight the need for behavior to be considered when assessing species' vulnerability to climate change.
When selecting prey, carnivores optimise energy gained when consuming prey against energy spent when pursuing and subduing prey. Additionally, predators seem to preferentially predate on prey which presents a low risk of injury. When defending itself against predators, baboons (Papio spp.) can inflict serious injury and cause mortality. Although part of Africa's large carnivores' diet, predation on baboons is usually avoided. We investigated prey selection patterns of African wild dogs (Lycaon pictus) in Mana Pools National Park, Zimbabwe. Based on direct and indirect observations and analyses of faecal samples, we show that baboons form a substantial part of the African wild dog diet and were more frequently predated on than would be expected based on availability. Predation on baboons did not vary over baboon sex or age classes but was affected by seasonality. This is the first study to describe a preference for predation on this unusual prey species.
In despotically driven animal societies, one or a few individuals tend to have a disproportionate influence on group decision-making and actions. However, global communication allows each group member to assess the relative strength of preferences for different options among their group-mates. Here, we investigate collective decisions by free-ranging African wild dog packs in Botswana. African wild dogs exhibit dominant-directed group living and take part in stereotyped social rallies: high energy greeting ceremonies that occur before collective movements. Not all rallies result in collective movements, for reasons that are not well understood.We show that the probability of rally success (i.e. group departure) is predicted by a minimum number of audible rapid nasal exhalations (sneezes), within the rally. Moreover, the number of sneezes needed for the group to depart (i.e. the quorum) was reduced whenever dominant individuals initiated rallies, suggesting that dominant participation increases the likelihood of a rally’s success, but is not a prerequisite. As such, the ‘will of the group’ may override dominant preferences when the consensus of subordinates is sufficiently great. Our findings illustrate how specific behavioural mechanisms (here, sneezing) allow for negotiation (in effect, voting) that shapes decision-making in a wild, socially complex animal society. © 2017 The Author(s) Published by the Royal Society. All rights reserved.
Climate change imposes an urgent need to recognise and conserve the species likely to be worst affected. However, while ecologists have mostly explored indirect effects of rising ambient temperatures on temperate and polar species, physiologists have predicted direct impacts on tropical species.
The African wild dog ( L ycaon pictus ), a tropical species, exhibits few of the traits typically used to predict climate change vulnerability. Nevertheless, we predicted that wild dog populations might be sensitive to weather conditions, because the species shows strongly seasonal reproduction across most of its geographical range.
We explored associations between weather conditions, reproductive costs, and reproductive success, drawing on long‐term wild dog monitoring data from sites in Botswana (20°S, 24 years), Kenya (0°N, 12 years), and Zimbabwe (20°S, 6 years).
High ambient temperatures were associated with reduced foraging time, especially during the energetically costly pup‐rearing period. Across all three sites, packs which reared pups at high ambient temperatures produced fewer recruits than did those rearing pups in cooler weather; at the non‐seasonal Kenya site such packs also had longer inter‐birth intervals. Over time, rising ambient temperatures at the (longest‐monitored) Botswana site coincided with falling wild dog recruitment.
Our findings suggest a direct impact of high ambient temperatures on African wild dog demography, indicating that this species, which is already globally endangered, may be highly vulnerable to climate change. This vulnerability would have been missed by simplistic trait‐based assessments, highlighting the limitations of such assessments. Seasonal reproduction, which is less common at low latitudes than at higher latitudes, might be a useful indicator of climate change vulnerability among tropical species.
Aggressive encounters may have important life history consequences due to the potential for injury and death, disease transmission, dispersal opportunities or exclusion from key areas of the home range. Despite this, little is known of their detailed dynamics, mainly due to the difficulties of directly observing encounters in detail. Here, we describe detailed spatial dynamics of inter-pack encounters in African wild dogs (Lycaon pictus), using data from custom-built high-resolution GPS collars in 11 free-ranging packs. On average, each pack encountered another pack approximately every 7 weeks and met each neighbour twice each year. Surprisingly, intruders were more likely to win encounters (winning 78.6% of encounters by remaining closer to the site in the short term). However, intruders did tend to move farther than residents toward their own range core in the short-term (1 h) post-encounter, and if this were used to indicate losing an encounter, then the majority (73.3%) of encounters were won by residents. Surprisingly, relative pack size had little effect on encounter outcome, and injuries were rare (<15% of encounters). These results highlight the difficulty of remotely scoring encounters involving mobile participants away from static defendable food resources. Although inter-pack range overlap was reduced following an encounter, encounter outcome did not seem to drive this, as both packs shifted their ranges post-encounter. Our results indicate that inter-pack encounters may be lower risk than previously suggested and do not appear to influence long-term movement and ranging.
Significance statement
Direct aggressive encounters between competitors are an important and potentially dangerous aspect of territoriality. In spite of this, detailed data on movements in response to encounters are lacking, especially for large mammals. Collecting observational data on competitors leaving an encounter site in different directions is logistically challenging, and radiocollar technology has previously been ineffective in this regard due to low temporal resolution. We overcame these issues by using custom-built high-resolution GPS collars, showing that intruding African wild dog packs were more likely to win inter-pack encounters (residents initially moved further away from the encounter). Inter-pack encounters appeared to have only short-term impacts on movement, with their outcome having no discernible impact on the long-term ranging patterns of African wild dog packs.
During 1990, two radio-marked packs of Lycaon pictus were monitored at three different times for 6-25 days each in the Masai Mara area of SW Kenya to estimate prey consumption rates. Male Thomson's gazelles Gazella thomsoni and young wildebeests Connochaetes taurinus were the most common prey. During either a morning (n = 19) or evening (n = 26) monitoring session, some packs did not hunt (11-45% of sessions) or hunted unsuccessfully (60-100% success/session). Packs sometimes lost part or all of a kill (0-27% of kills) to avian or mammalian scavengers. Minimum estimated consumption rates for all three packs (0.08-0.20 kg prey/kg dog/day) seemed to reflect, at a minimum, variation in hunting success, age of pups, and competition with other species (related to pack size). -Authors
Background
Spacing patterns mediate competitive interactions between conspecifics, ultimately increasing fitness. The degree of territorial overlap between neighbouring African wild dog (Lycaon pictus) packs varies greatly, yet the role of factors potentially affecting the degree of overlap, such as relatedness and pack size, remain unclear. We used movement data from 21 wild dog packs to calculate the extent of territory overlap (20 dyads).
Results
On average, unrelated neighbouring packs had low levels of overlap restricted to the peripheral regions of their 95% utilisation kernels. Related neighbours had significantly greater levels of peripheral overlap. Only one unrelated dyad included overlap between 75%-75% kernels, but no 50%-50% kernels overlapped. However, eight of 12 related dyads overlapped between their respective 75% kernels and six between the frequented 50% kernels. Overlap between these more frequented kernels confers a heightened likelihood of encounter, as the mean utilisation intensity per unit area within the 50% kernels was 4.93 times greater than in the 95% kernels, and 2.34 times greater than in the 75% kernels. Related packs spent significantly more time in their 95% kernel overlap zones than did unrelated packs. Pack size appeared to have little effect on overlap between related dyads, yet among unrelated neighbours larger packs tended to overlap more onto smaller packs’ territories. However, the true effect is unclear given that the model’s confidence intervals overlapped zero.
Conclusions
Evidence suggests that costly intraspecific aggression is greatly reduced between related packs. Consequently, the tendency for dispersing individuals to establish territories alongside relatives, where intensively utilised portions of ranges regularly overlap, may extend kin selection and inclusive fitness benefits from the intra-pack to inter-pack level. This natural spacing system can affect survival parameters and the carrying capacity of protected areas, having important management implications for intensively managed populations of this endangered species.
It has long been recognized that superior carnivores can impact on the demography and ecology of smaller members of the guild, although exact mechanisms remain unclear. Here we use original data from a unique natural experiment to study some of the mechanisms by which African lions Panthera leo impact on African wild dogs Lycaon pictus. Using a study site where wild dogs outnumbered lions for several years prior to lion population recovery, we aimed to investigate whether or not, and by which means, wild dog populations are regulated and influenced by lions. We used 38 pack-years of demographic and behavioural data across two 4-year periods where lion density differed 20-fold (pre-lion era: 1996–1999 and lion era: 2010–2013) to assess how lions may affect wild dog pack size and age structure, litter size and pup survival (n = 329 pups), as well as den site selection (n = 46 dens). Pack size was significantly greater during the pre-lion era. The pup to adult ratio was lower during the lion era and the change in pack composition was directly attributable to significantly greater lion-induced pup mortality. We also demonstrate a behavioural shift, with locations selected for the vulnerable denning period being in more rugged terrain and in areas with lower prey densities during the lion era, as compared with the pre-lion era. Lower adult recruitment into a population of an obligate cooperative breeder like the African wild dog can have complex consequences, including on feeding and defence of young, and mate finding.
Tropical deforestation continues to be a major driver of biodiversity loss and greenhouse gas emissions. Remote sensing technology is increasingly used to assess changes in forest cover, species distributions and carbon stocks. However, satellite and airborne sensors can be prohibitively costly and inaccessible for researchers in developing countries. Here, we describe the development and use of an inexpensive (<$2,000) unmanned aerial vehicle for surveying and mapping forests and biodiversity (referred to as ‘Conservation Drone’ hereafter). Our prototype drone is able to fly pre-programmed missions autonomously for a total flight time of ~25 minutes and over a distance of ~15 km. Non-technical operators can program each mission by defining waypoints along a flight path using an open-source software. This drone can record videos at up to 1080 pixel resolution (high definition), and acquire aerial photographs of <10 cm pixel resolution. Aerial photographs can be stitched together to produce real-time geo-referenced land use/cover maps of surveyed areas. We evaluate the performance of this prototype Conservation Drone based on a series of test flights in Aras Napal, Sumatra, Indonesia. We discuss the further development of Conservation Drone 2.0, which will have a bigger payload and longer range. Initial tests suggest a flight time of ~50 minutes and a range of ~25 km. Finally, we highlight the potential of this system for environmental and conservation applications, which include near real-time mapping of local land cover, monitoring of illegal forest activities, and surveying of large animal species.
Signals are shaped through selective pressures impacting their information content (i.e. 'what' is conveyed) and their efficacy (i.e. 'how' is it conveyed). In the case of long-range communication, a signal's structure should both convey information and allow for detection and discrimination despite the effects of environmental variability during propagation. Canid howls are an ideal example of a long-range communication signal, although research has mostly focused on the relationships between howls' acoustic characteristics and their potential information content in wolves, Canis lupus spp., and coyotes, Canis latrans. In this study, we quantified these relationships in another canid, the dingo, Canis familiaris dingo, to determine how their howls compare to that of other wild canids. We found that dingoes' howls are individually distinctive and may convey gender cues. Playback experiments indicate that dingoes can perform class-level recognition of familiar and unfamiliar individuals on the basis of vocalizations alone. These results mirror findings for other wild canids such as wolves and coyotes. Lastly, propagation experiments demonstrate that this signal's structure can permit long-distance detectability and discriminability. We discuss our results in relation to the putative functions of canid howls and propose avenues for future research.
African wild dogs (Lycaon pictus) are described as highly collaborative endurance pursuit hunters based on observations derived primarily from the grass plains of East Africa. However, the remaining population of this endangered species mainly occupies mixed woodland savannah where hunting strategies appear to differ from those previously described. We used high-resolution GPS and inertial technology to record fine-scale movement of all members of a single pack of six adult African wild dogs in northern Botswana. The dogs used multiple short-distance hunting attempts with a low individual kill rate (15.5%), but high group feeding rate due to the sharing of prey. Use of high-level cooperative chase strategies (coordination and collaboration) was not recorded. In the mixed woodland habitats typical of their current range, simultaneous, opportunistic, short-distance chasing by dogs pursuing multiple prey (rather than long collaborative pursuits of single prey by multiple individuals) could be the key to their relative success in these habitats.
African wild dogs (Lycaon pictus) are reported to hunt with energetically costly long chase distances. We used high-resolution GPS and inertial technology to record 1,119 high-speed chases of all members of a pack of six adult African wild dogs in northern Botswana. Dogs performed multiple short, high-speed, mostly unsuccessful chases to capture prey, while cheetahs (Acinonyx jubatus) undertook even shorter, higher-speed hunts. We used an energy balance model to show that the energy return from group hunting and feeding substantially outweighs the cost of multiple short chases, which indicates that African wild dogs are more energetically robust than previously believed. Comparison with cheetah illustrates the trade-off between sheer athleticism and high individual kill rate characteristic of cheetahs, and the energetic robustness of frequent opportunistic group hunting and feeding by African wild dogs.
The reasons African wild dog (Lycaon pictus) populations declined to endangered status continent-wide have been difficult to document. However, demographic research to date indicates the following. Annual pack range size (150–3800 km2), density (2–35 dogs/1,000 km2), and territorial propensity of wild dogs appear related to prey density and temporal distribution, and habitat structure. Wild dogs usually live in packs of 10–14 composed of 1 or more adult females unrelated to 1 or more adult males, and their current or older offspring. Sex ratios of adults, yearlings, and pups usually are skewed toward males. Annually, usually 1 but sometimes 2 pack females breed and produce 8–12 pups each (up to 23 total); timing and frequency of parturition appears to coincide with prey abundance. Annual adult survival usually ranges from 0.65–0.85 and likely is most influenced by human-related mortality factors and disease (e.g., rabies and anthrax). Pup survival (0.1473x2013;0.73) appears to be influenced by number of adults in the pack and food availability. Dispersing wild dogs usually do so with same-sex siblings when 1.0–2.0 years old. Nutritional factors and perhaps natal pack composition likely affect the rates at which male or female wild dogs disperse. Dispersing groups join established packs or meet up with opposite sex groups and settle to establish new packs; dispersal distances may exceed 200 km. Observed annual finite rates of increase (k) for African wild dogs have ranged from 0.83–1.77, but potential rates may exceed 2.0. Reduced adult mortality, coupled with high pup survival and their subsequent dispersal as yearlings, can provide a mechanism by which populations decimated by catastrophic disease or human destruction can quickly rebuild if sufficient habitat is available. Collaborative ongoing research throughout a variety of habitats in Africa will facilitate examination of wild dog population dynamics, and provide information critical to conservation efforts.
Identifying specific signaling components within complex mixtures is a common problem in semiochemistry. Both glandular secretions and excretory products contain components of semiochemical importance, but identifying these signals is problematic because they are usually parts of mixtures with several 100 components, of which only a subset may be involved with signaling. In contrast to waste and metabolic byproducts—which can be expected to vary both between and within individuals according to extrinsic factors—signaling compounds are expected to be uniform among animals sending the same signal and stable over time. In group-living territorial species we would expect there to be a degree of group-specificity in signals that advertise territory residence. As part of an ongoing study investigating and manipulating scent-marking and territorial behavior in African wild dogs, several 100 volatile components have been located from their urine. How many and which, if any, of these have active roles in semiochemical communication of territory residence is currently unknown. Observations of scent marking behaviors of African wild dogs strongly suggest that dominant urine overmarks (DUOs)—where one member of a pair deposits urine on the urine of its partner—are the most likely source of such signals. We used multivariate statistics to investigate >990 separated chemical components (some of which could be multiple compounds) found in these DUOs, and found as few as 10 chemical components that together enabled statistical discrimination of specific dominant pairs. We suggest that this method may be broadly applied across communication systems to locate components of signals within complex “mixtures.”
Understanding the degree to which animals are shifting their phenology to track optimal conditions as the climate changes is essential to predicting ecological responses to global change. Species at low latitudes or high trophic levels are theoretically expected to exhibit weaker phenological responses than other species, but limited research on tropical systems or on top predators impedes insight into the contexts in which these predictions are upheld. Moreover, a lack of phenological studies on top predators limits understanding of how climate change impacts propagate through entire ecosystems. Using a 30-y dataset on endangered African wild dogs ( Lycaon pictus ), we examined changes in reproductive phenology and temperatures during birthing and denning over time, as well as potential fitness consequences of these changes. We hypothesized that their phenology would shift to track a stable thermal range over time. Data from 60 packs and 141 unique pack-years revealed that wild dogs have delayed parturition by 7 days per decade on average in response to long-term warming. This shift has led to temperatures on birthing dates remaining relatively stable but, contrary to expectation, has led to increased temperatures during denning periods. Increased denning temperatures were associated with reduced reproductive success, suggesting that a continued phenological shift in the species may become maladaptive. Such results indicate that climate-driven shifts could be more widespread in upper trophic levels than previously appreciated, and they extend theoretical understanding of the species traits and environmental contexts in which large phenological shifts can be expected to occur as the climate changes.
We studied the dietary patterns of African wild dog in Vumbura and Linyanti –Selinda regions, in northern Botswana. We estimated the densities of potential wild dog prey ungulate using Distance sampling techniques. Scat analysis and direct observations of wild dog kills were used to analyze the dietary characteristics. Pianka and Levin's indices were used to compare dietary overlaps and niche breadths of the wild dog packs in these sub-populations. The density of impala was higher than that of medium and large size ungulates in both study sites. Prey preference was tested using Jacob's index. Wild dog diets in Vumbura showed significant overlaps with that of wild dogs in Linyanti–Selinda sub-population. There was no significant difference in the seasonal dietary composition of wild dogs in both regions. Impala was the most common prey species but other medium sized ungulates were widely preferred by wild dogs. This finding is similar to that of other studies from other southern African reserves. Literature suggests that the Okavango Delta and Linyanti-Kwando Rivers systems have a hydro-geological connection; and the findings of the present study suggest an ecological resemblance, shown here by wild dog dietary similarities. Hence it is imperative for conservationist to adopt a wider ecosystem management approach to solve conservation problems of highly mobile and spatially demanding large carnivores.
The African wild dog ( Lycaon pictus ), a rare canid native to southern and eastern Africa, lives and hunts in complex social groups. It is currently classified as Endangered on the IUCN Red List of Threatened Species, with approximately 1400 mature individuals present in the wild. L. pictus is distinct among canids in lacking a digit I or “dew claw” and in its use of exhaustive predation to capture its prey instead of speed, strength, or stealth. These behavioral and morphological traits suggest a potentially unique set of adaptations. This study is the first detailed anatomical description and functional analysis of the forelimbs of L. pictus .
The forelimb myology of L. pictus is generally similar to other canids; however, it shows some notable exceptions. While a complete digit I is absent in L. pictus , a vestigial first metacarpal is present, resulting in changes to insertions of mm. extensor digiti I et II , abductor (et opponens) digiti I , and flexor digiti I brevis . M. triceps brachii caput laterale had a larger origin in L. pictus compared to other carnivorans, and m. triceps brachii caput longum had an additional accessory head. Electromyographic (EMG) studies have shown this muscle is active during the stance phase of trotting and galloping and is important for storing elastic energy during locomotion. Mm. anconeus , brachialis , and flexor carpi ulnaris caput ulnare all had more extensive origins in L. pictus than other canids. In domestic dogs, these muscles have a relatively high proportion of Type 1 (slow‐twitch) fibers and are important for posture and elbow stability. Statistical analyses of the quantitative muscle data reveal similar proportions of antebrachial muscle groups to other large‐bodied carnivorans. However, L. pictus has relatively smaller wrist rotators than any other included taxon, suggesting a need for stability over rotatory movement in the carpus of L. pictus .
We interpret these differences in size and attachments of muscles in L. pictus compared to other canids as adaptations for long distance running in this highly cursorial species, likely important for exhaustive predation. Absence of a digit I in L pictus , typically used to reduce torque during quick turns and for lightly gripping onto objects, may be related to a reduced need for gripping and quick agile movements in its cursorial lifestyle.
Support or Funding Information
This project was funded by Midwestern University, including a Kenneth A. Suarez Summer Research Fellowship to RK.
Dispersal behaviour plays a key role in social organisation, demography and population genetics. We describe dispersal behaviour in a population of African wild dogs ( Lycaon pictus ) in Kenya. Almost all individuals, of both sexes, left their natal packs, with 45 of 46 reproductively active “alpha” individuals acquiring their status through dispersal. Dispersal age, group size and distance did not differ between males and females. However, only females embarked on secondary dispersal, probably reflecting stronger reproductive competition among females than males. When dispersing, GPS‐collared wild dogs travelled further than when resident, both in daylight and by night, following routes an order of magnitude longer than the straight‐line distance covered. Dispersers experienced a daily mortality risk three times that experienced by adults in resident packs. The detailed movement data provided by GPS‐collars helped to reconcile differences between dispersal patterns reported previously from other wild dog populations. However, the dispersal patterns observed at this and other sites contrast with those assumed in published demographic models for this endangered species. Given the central role of dispersal in demography, models of wild dog population dynamics need to be updated to account for improved understanding of dispersal processes.
Understanding and quantifying a large carnivores’ feeding behaviour is a key component in determining its functional significance in an ecosystem, both in terms of its top‐down influence on prey species, but also its relationships with sympatric carnivores. Dietary overlap is one of the numerous niche dimensions used to characterize resource partitioning and potential competition within a community. We characterize the diet, potential dietary niche overlap and prey preference of a large African carnivore guild on small fenced protected areas. To quantify the potential inter‐ and intraspecific foraging competition, we analysed 5,128 kills, representing 35 prey species made by African wild dogs Lycaon pictus (n = 553), cheetahs Acinonyx jubatus (1,427), lions Panthera leo (2,648) and leopards P. pardus (500). Our results show that large African carnivores in small protected areas are exposed to considerable overlap in dietary resource utilization. At the interspecific level, African wild dogs and cheetahs displayed the greatest vulnerability to potential dietary competition. Lions exhibited marked differences in prey preference, mass and species utilization compared to the other carnivores. African wild dogs and cheetah females with dependent offspring occupied the greatest potential for dietary competition within the large carnivore guild. Using a case study based on the preferred biomass of prey available, we estimate the sustainable density of large carnivores at a small fenced prospective African wild dog reintroduction site. African wild dogs displayed the lowest mean predicted density compared to all sympatric predators with an expected population size of 7 individuals. Our research highlights the need to assess the influence of competitive forces in structuring and restoring large predators to portions of their historical range by identifying species most vulnerable to a potential reintroduction attempt. In the absence of controlled experiments, elucidating the influences of exploitation competition is challenging, and only through manipulating sympatric species presence and densities can these complex interactions be fully understood. We characterize the diet, potential dietary niche overlap and prey preference of a large African carnivore guild on small fenced protected areas. Our results show that large African carnivores in small protected areas are exposed to considerable overlap in dietary resource utilization. African wild dogs and cheetah females with dependent offspring occupied the greatest potential for dietary competition within the large carnivore guild. Our research highlights the need to assess the influence of competitive forces in structuring and restoring large predators to portions of their historical range by identifying species most vulnerable to a potential reintroduction attempt.
South Africa holds a viable population of the endangered African wild dog (Lycaon pictus), with almost 500 individuals divided into (1) an unmanaged population in the Kruger National Park (KNP), (2) a free-roaming population, and (3) a managed metapopulation (MTP) that originated from reintroductions. Because metapopulation reserves are geographically isolated, translocations are ongoing to mimic natural dispersal. During this study, we questioned whether the metapopulation management plan for wild dogs has been successful at maintaining healthy levels of genetic diversity and avoiding inbreeding in packs. We evaluated whether the current approach is effective for long-term population viability and assessed whether population admixture occurs between the three populations. To achieve this, we amplified 20 microsatellite loci for genetic analysis. We found high levels of genetic variation, likely resulting from translocations and artificial pack formation. Results showed that in the absence of any management intervention, the MTP would lose 48% of its heterozygosity over a 100-year trajectory, and KNP 12% heterozygosity. Under the current management scenario, the MTP will maintain 95% of its heterozygosity. We found genetic evidence that limited recent dispersal occurs between the MTP and KNP (FST = 0.06). In conclusion, the metapopulation management plan can be considered successful based on the achieved population growth and preservation of genetic diversity. Our study highlights that genetic data form a critical part of conservation management, and that translocations can be a vital tool to restore genetic variability of species.
Division of labour, in terms of providing for offspring, in obligate cooperatively breeding mammalian species is poorly understood. To understand offspring provisioning in a cooperatively breeding canid, we analysed a long-term dataset comprising 22 African wild dog, Lycaon pictus, denning events (nine packs over nine consecutive years). We investigated the effects of sex, age class, social status, and pack size on the likelihood and frequency of regurgitating food to pups at the den. We found that the interaction of social status and pack size affected the likelihood of regurgitation. Specifically, when in a large (≤15) pack, dominant individuals were less likely to regurgitate than subordinate individuals. However, in smaller (≤ 15) packs, dominant individuals were more likely to regurgitate than subordinate individuals. We also found that the interaction of age and pack size affected the frequency of regurgitation. Specifically, in large packs, yearlings regurgitated more frequently per observation period than adults. Contrastingly, in smaller packs, adults regurgitated more frequently. Sex did not affect pup provisioning. We suggest that these contrasting patterns of helping are best explained by a strong selection pressure for individual behaviour that results in larger pack sizes in this species. When in larger packs, costs are shared as the division of labour spreads amongst individuals. In smaller packs, a division of labour requires individuals that already experience costs (such as reproduction) to be further burdened by provisioning. Overall, our results support that the need for more helpers to care for offspring contributes to the evolutionary consequence of an inverse density dependence.
Understanding the natural behaviour and coexistence of species is important for the conservation of intact ecosystems, and behavioural studies can enhance our knowledge of processes such as communication and competition. I investigated the social dynamics and scent-marking behaviour of spotted hyaenas (Crocuta crocuta), and the occurrence of interspecific olfactory eavesdropping among African mammals, within the Okavango Delta ecosystem of Botswana. First, social network analysis found that the hyaena population was comprised of five main clans that maintained territories but whose home ranges overlapped considerably. Scavenging at large carcasses involved associations between individuals from different clans and resulted in relative tolerance toward territorial intruders. Second, observations of communal latrine use found that latrines are likely involved in territorial advertisement by hyaena clans, and cyclical patterns of latrine growth and decline were linked to annual rainfall. Third, a translocation experiment showed that hyaena scats appear to be less important for hyaena communication than other cues associated with latrines, especially as hyaenas did not differ in their behaviour towards scat originating from latrines located in resident versus non-resident clan home ranges. Heterospecific mammals investigated, scent-marked, and were vigilant at hyaena latrines, suggesting a potential function for hyaena latrines in interspecific eavesdropping and/or communication. Fourth, a urine presentation experiment found that the investigation of sympatric predator urine by African mammals stimulated vigilance behaviour, suggesting that olfactory signals provide information about predation risk. Hyaenas exhibited context-specific differences in behaviour towards predator urine: they were more likely to investigate urine samples alongside indicators of predator activity (i.e. carrion odour, carcasses) and were most likely to exhibit vigilance at carcasses when exposed to urine from lions and wild dogs. This study greatly enhanced our understanding of spotted hyaena behaviour within the Okavango Delta, an important ecosystem for the conservation of African large predators. Furthermore, this study provided the first experimental evidence of the role of hyaena scats in intraspecific communication and interspecific olfactory eavesdropping at latrines. My research findings regarding the population’s clan structure and home ranges will form the foundation for subsequent investigation into human-wildlife conflict in the study area. Furthermore, the results from two scent experiments shed light on the potential importance of olfactory signals for mediating interspecific interactions among African mammals, particularly among large predators.
Researchers argue that human–wildlife conflict (HWC) can be understood better in terms of conflict between humans over wildlife. We explore human conflict over wildlife by using a social constructionist approach to examine meanings of African wild dogs in Botswana. In 2013 and 2015, we conducted a qualitative study in four study sites by completing: (a) 113 semi-structured interviews with individuals in the agricultural, conservation, and tourism sectors; (b) participant observation; and (c) document analysis. Our results reveal that wild dogs are socially constructed as problem animals, as an endangered species, and as an economic resource, reflecting stakeholders’ diverging agendas, priorities, and values. The social constructions are driven by and emblematic of politico-economic and sociocultural trends, and competing development trends in Botswana. We propose: (a) seeing HWC as human conflict over wildlife can increase communication between conservationists and affected communities, and (b) integrative management plans that increase collaboration among stakeholder groups.
Habitat quality is often assumed to be directly related to increased consumer density, but such assumptions cannot be made without supporting demographic data that indicate improved fitness. Habitat selection might be especially important for denning species, where vulnerable offspring are confined to a single location for extended periods, but the effect of den choice on the reproductive success of denning species is poorly understood. By combining airborne high-resolution Light Detection and Ranging (LiDAR) measurements with data on pack composition, we investigated den site selection by endangered African wild dogs in Hluhluwe-iMfolozi Park, South Africa, examining whether habitat selection based on ecological factors resulted in increased litter sizes and thus reproductive success compared with social factors known to be important. Although there was selection for den sites in areas of increased terrain ruggedness and vegetation density, only vegetation density was associated with larger litter sizes and translated into increased reproductive success. Moreover, pack size was only influential when a minimum vegetation density around den sites was achieved, indicating that although social variables have a powerful effect on reproductive success, they are mediated by ecological factors defining habitat quality. Our results demonstrate the importance of distinguishing between density-and fitness-based indicators of habitat quality , and how this can affect management actions, particularly for endangered species conservation.
The hunting patterns of a pack of African wild dogs (Lycaon pictus) were monitored on an 8356 ha reserve in the Waterberg Mountains, Limpopo Province, South Africa. Some members of the pack were radio-collared and the dogs were followed daily by researchers from April 2002 to January 2003. Prey selection and the use of barriers during the wild dogs' hunts were studied. Barriers were defined as objects such as game fences, flowing rivers and dams, which impeded a fleeing prey animal's escape. Kudu (Tragelaphus strepsiceros) comprised the majority (60%) of the dogs' kills, although they made up only 14% of the total prey items available to the dogs. Wild dogs in the reserve made 81% of their kills within 20 m of a barrier, although these 20 m zones made up only 1.7% of the total area available to the dogs in the reserve. Being able to factor the use of barriers into their hunts could explain the preponderance of large prey in their diet. Because wild dogs make most of their kills near or at barriers, there are important management implications of having wild dogs in small reserves. These include ensuring that fences are sturdy and monitored for damage which might occur during hunts. The ability of wild dogs to successfully target the larger prey animals may also have an effect on the carnivore/prey balance and should be monitored carefully.
African wild dogs (Lycaon pictus) are endangered, having disappeared from many areas where other large carnivore species have persisted. The relative vulnerability of this species has been attributed variously to its disproportionate exposure to anthropogenic threats, limitation by larger competing predators, and Allee effects caused by obligate cooperative breeding. The natural recovery of a wild dog population living on private and community land in northern Kenya provided an opportunity to investigate these potential constraints on population growth. Within a decade the population increased from near-extinction to become the 6th largest in the world. Rates and causes of mortality, and reproductive rates, were similar on community lands, where people and livestock were abundant but competing predators suppressed, and on commercial ranches, where human and livestock densities were lower but competitors more abundant. Larger packs produced larger litters, indicating a component Allee effect. However, because pack size was unrelated to population size, growth of the population was not impeded at low densities; that is, no demographic Allee effect was detectable. These results show that, despite earlier concerns, wild dogs can achieve rapid population recovery, even in a human-dominated landscape. This recovery was probably facilitated by local pastoralist traditions, which combine vigilant herding of livestock with little or no hunting of wild prey. This success might be replicated in other areas where traditional pastoralism is still practiced.