The socio-ecology of a plural breeding species: The banded mongoose (Mungos mungo) in Queen Elizabeth National Park - Uganda

In this thesis I investigate the impact of ecological factors on the costs and benefits of group living in a population of banded mongooses (Mungos mungo) in Queen Elizabeth National Park, Uganda, and test several of the theoretical predictions generated by reproductive skew models. Despite two earlier studies of this species, this represents the first comparative study examining the effects of ecological (food availability, predation pressure, potential for dispersal) and social factors on survival and reproduction. Breeding in the banded mongoose is egalitarian, with offspring raised communally. By assessing the effect of pack size on individual variation in body condition, reproduction and probability of dispersal, I show that optimal pack size varied with the differing costs and benefits of sociality in males and females. Males were competing more for mates, whilst females benefited from the availability of helpers. Individuals were more likely to disperse from large packs and animals were more likely to emigrate in groups rather than alone. Dominance rank did not affect the survival or reproduction of either sex and there was no evidence of reproductive suppression. These findings support the prediction of reproductive skew models which states that low skew within groups is expected when there are no substantial differences between fighting abilities of group members. Although predation risks were not different for individuals in large and small packs, the vigilance system was more costly for individuals living in small packs. The effect of temporal variation in food resources on reproduction and survival was limited, but varied according to the type of prey available. Large packs consistently had better access to richer food resources. They were also able to forage more efficiently when food abundance was low due to the advantages of co-operative foraging