Dispersal behaviour of African wild dogs in Kenya

Abstract

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.

Within‐ and between‐group dynamics in an obligate cooperative breeder

“…Although individual mortality was lower in larger packs (Figure c), there was no detectable prolongation of pack longevity. Only one pack persisted beyond the lifetime of all its original founders, a unique event associated with the only time we observed immigration to a pack in which alphas of both sexes were still present and the only time we observed an animal inherit alpha status in its natal pack (Woodroffe, Chapman, & Lemusana, ; Woodroffe et al, ). The longevity of this pack (8.2 years) was exceeded by that of one other pack, in which both alphas at termination were founders (Figure c).…”

“…However, while dispersers were lost to their origin packs, most were not lost to the population. In a previous study, we showed that 57% of radiocollared dispersers formed new packs, 4% joined existing packs to replace a dead alpha, 22% were lost to monitoring, and 17% died (Woodroffe et al, ). Hence, although larger packs grew in size more slowly than smaller packs, they did not contribute less to overall population growth, because they generated new packs at a higher rate (Figure j).…”

“…Following Woodroffe et al (), we defined a wild dog pack as a stable social group including members of both sexes. Packs were formed by one or more males bonding with one or more females unrelated to them (McNutt, ); we termed these animals pack founders.…”

“…We considered packs to be persisting as long as they contained at least one founder, or founders' descendants of both sexes, and to have terminated when these criteria were no longer met. Pack termination resulted either from whole‐pack death (as can occur, for example, in a disease outbreak, Gascoyne et al, ) or from pack break‐up, when all male pack members separated permanently from all female pack members (Woodroffe et al, ).…”

“…We considered yearlings to be adult because wild dogs are able to reproduce as yearlings given the opportunity (e.g. in captivity, Rhodes, Quick, & Long, ; Verberkmoes & Verberkmoes, ) and because, in our study area, 25% of radiocollared dispersers (seeking reproductive opportunities) were yearlings (Woodroffe et al, ).…”