Heading for the Hills: Risk Avoidance Drives Den Site Selection in African Wild Dogs

Abstract

Compared to their main competitors, African wild dogs (Lycaon pictus) have inferior competitive abilities and interspecific competition is a serious fitness-limiting factor. Lions (Panthera leo) are the dominant large carnivore in African savannah ecosystems and wild dogs avoid them both spatially and temporally. Wild dog young are particularly vulnerable and suffer high rates of mortality from lions. Since lions do not utilize all parts of the landscape with an equal intensity, spatial variation in lion densities can be exploited by wild dogs both during their general ranging behaviour, but more specifically when they are confined to a den with vulnerable young. Since patches of rugged terrain are associated with lower lion densities, we hypothesized that these comparatively safe habitats should be selected by wild dogs for denning. We investigated the relationship between the distribution of 100 wild dog den sites and the occurrence of rugged terrain in four wild dog populations located in Tanzania, Zimbabwe and South Africa. A terrain ruggedness index was derived from a 90 m digital elevation model and used to map terrain ruggedness at each site. We compared characteristics of actual and potential (random) den sites to determine how wild dogs select den sites. The distributions of wild dog dens were strongly associated with rugged terrain and wild dogs actively selected terrain that was more rugged than that available on average. The likelihood of encountering lions is reduced in these habitats, minimizing the risk to both adults and pups. Our findings have important implications for the conservation management of the species, especially when assessing habitat suitability for potential reintroductions. The simple technique used to assess terrain ruggedness may be useful to investigate habitat suitability, and even predict highly suitable denning areas, across large landscapes.

Reproductive class influences risk tolerance during denning and spring for American black bears (Ursus americanus)

“…Den sites are an important aspect of many mammalian species' ecology, and risk avoidance (e.g., anthropogenic, conspecific, predation) has been found to influence den site selection of several carnivore species (Theuerkauf et al 2003, Libal et al 2011, Jackson et al 2014. We found that black bears appeared to minimize anthropogenic risk during denning; however, females with cubs must also balance the increased energetic demands of rearing young while minimizing their mortality risk.…”

“…, Jackson et al. ). We found that black bears appeared to minimize anthropogenic risk during denning; however, females with cubs must also balance the increased energetic demands of rearing young while minimizing their mortality risk.…”

“…), which places strong selective pressures on strategies that optimize offspring survival (Jackson et al. ). Mammalian hibernation is a behavioral and physiological strategy to avoid seasonal shortages of food and water, consisting of periods of low activity and metabolic suppression (Watts et al.…”

“…The seasonal timing of life-cycle events such as reproduction, migration, or hibernation can greatly influence survival and reproductive success (Caro et al 2013), which places strong selective pressures on strategies that optimize offspring survival (Jackson et al 2014). Mammalian hibernation is a behavioral and physiological strategy to avoid seasonal shortages of food and water, consisting of periods of low activity and metabolic suppression (Watts et al 1981, Humphries et al 2003.…”

No evidence of handling‐induced mortality in Serengeti's African wild dog population

“…Lions and hyaenas respond to this resource variability and, as the dominant apex carnivores, select the most resource‐rich habitats, avoiding rugged areas, for instance, in favor of prey‐rich flatter terrain (Mills & Gorman, ). The resulting spatial variability in lion and hyaena densities facilitates avoidance by subordinate wild dogs (Mills & Gorman, ) and the development of a landscape of fear where high‐risk habitats are avoided and competition refuges are actively selected, particularly during the vulnerable denning season when rugged and densely vegetated areas, with fewer lions, are selected by wild dogs (Davies, Marneweck, Druce, & Asner, ; Jackson et al, ). Indeed, fluctuations in lion densities have been shown to elicit changes in wild dog behavior and habitat selection (Groom et al, ).…”