Abstract:
The interspecific differences in sociality between closely related taxa are generally attributable to differences in habitats, foraging ecology, predation and resource distribution (Rubenstein & Wrangham 1986). The social organisation of mongooses can be placed along a continuum ranging from aggregated, asocial individuals (e.g. Galerella pulverolenta (pers. obs.)), through moderately social female/male kin clusters and familial groups ( e.g. Cynictis penicillata (pers. obs.)), to highly social groups ( e.g. Helogale sp. (Rasa 1977), Suricata (pers. obs.). The most social of the mongooses tend to be the smaller diurnal species living in matriarchal groups. Rasa (1976) has noted that viverrid species inhabiting exposed plains areas with little or no cover have almost all evolved a relatively high degree of sociality (Helogale, Suricata, Mungos, Crossarchus) whilst larger, nocturnal and arboreal species occupying denser habitats tend to solitary or pair living (Ichneumon sp., Herpestes sp., Atilax). The major factor involved in the evolution of sociality in the smaller species appears to be predation pressure in an exposed environment and the subsequent necessity for effective anti-predation mechanisms. Sociality among carnivores is generally related to in terms of cooperative hunting (Kleiman & Eisenberg 1973; Kruuk 1972; Schaller 1972) and group defence against predators (Rasa 1986). Group size in many species of carnivores may be determined by the food resource size and availability (Bekoff & Wells 1980; Caraco & Wolf 1975). However, as Waser (1980) points out, the apparent success of models relating the degree of sociality to resource dispersal falls short when considering viverrids. As an alternative, Waser suggests that the renewal rate of a prey resource, rather than its actual distribution, is instrumental in the selection for sociality in viverrids.
