Group size, survival, reproduction, and routes to breeding in dwarf mongooses

Abstract

Survival and reproduction in a marked population of dwarf mongooses, Helogale parvula, were studied for a period of 13 years in the Serengeti National Park, Tanzania. Dwarf mongooses live in packs with a mean size of 8·9 containing a dominant breeding pair, usually, the oldest individuals. Survivorship of both juveniles and adults is positively related to pack size. Packs containing eight (the median) or more members raised twice as many offspring to yearling status as did smaller packs. Most males and many females became breeders following emigration from their natal packs. Of emigrants that attained breeding status, most (both males and females) did so by founding new packs. Males sometimes became breeders by emigrating with other males and ousting male breeders in another group. Many females and some males waited to succeed alphas of the same sex in their natal packs. The median age class when alpha status was attained (3 years old) and when breeding tenure ended (5 years old) was the same in both sexes, but females that became breeders following emigration attained alpha status earlier than those that attained status in their natal packs.