We discuss the relative importance of the food resource and other factors in determining jackal social and spatial organization. Among carnivores there is considerable variation in social and spatial organization between species, within species and within populations over space and time. An increasing body of evidence points to http://www.selleckchem.com/products/AZD2281(Olaparib).html resource-based explanations (Macdonald,

1983; Geffen et al., 1996). For example, studies of social carnivores have linked territory size to the dispersion of resources (typically food) within their range, and group size to resource availability (Macdonald, 1983). Meanwhile, theoretical models predict territoriality breaks down when food resources become very abundant either because the amount of food exceeds intruder pressure such that competition ceases,

or competitors are so numerous that excluding them would require more energy than is warranted by territory defence (Maher & Lott, 2000). However, field studies suggest that traditional models fail to capture the complexity and flexibility observed in wild populations. For example, studies of spotted hyaena Crocuta crocuta, showed group and territory size become decoupled from measures of resources in the territory when individuals undertake regular extra-territorial foraging excursions, while territoriality persists in the presence of a super abundance of food (Hofer & East, 1993a,b). Investigating the impacts of resource-use in other species where populations are reliant on clumped and abundant food resources Volasertib concentration offers an opportunity to further elucidate the relative importance of resource-based explanations for understanding variation in carnivore social and spatial organization. To date such studies are rare, either because this scenario rarely occurs as a stable system in the wild or because it is difficult to observe when it does. At Phosphatidylinositol diacylglycerol-lyase Cape Cross Seal Reserve (CCSR) in Namibia a black-backed jackal Canis mesomelas population meets the unusual criteria of being reliant on a food resource that is clumped, abundant

and available year-round. The black-backed jackal is a highly adaptive, medium-sized canid that occurs in various habitats, acting as predator and scavenger, and adopting an omnivorous diet that varies with food availability (Loveridge & Nel, 2004). At CCSR, jackals feed on Cape fur seals Arctocephalus pusillus which provide an abundant year-round food source (Nel & Loutit, 1986; Hiscocks & Perrin, 1987). The availability of alternative prey in the gravel desert that flanks the coastline is extremely low (Loveridge & Nel, 2004) thus jackals rely on fur seals as their primary food source and ‘commute’ from inland and along the coast to the colony to feed (Hiscocks & Perrin, 1988). As facultative cooperative breeders, mated pairs are sometimes joined by subordinates that may help raise the current litter (Moehlman, 1983). At CCSR, the jackals’ breeding season is highly synchronized.