Social control of reproduction in banded mongooses

Recent theoretical work suggests that the distribution of reproduction, or degree of reproductive skew, in animal societies depends crucially on (1) w hether dominant individuals can fully control subordinate reproduction, and (2) how subordinate reproduction affects the fitness of dominants. I inves tigated these two factors in cooperatively breeding banded mongooses, Mungo s mungo. Female packmates entered oestrus together and were closely guarded by dominant males. These males were aggressive to subordinate males who at tempted to mate, but females still managed to mate with males other than th eir mate guard. Older females were guarded and mated a few days before thei r younger packmates, yet all females usually gave birth on the same day, su ggesting that older females may have a longer gestation period. Moreover, o lder females carried more fetuses. Overall, ca. 83% of adult females concei ved in each breeding attempt and 71% carried to term. These results indicat e that, among males, dominant individuals did not have full control over th e mating attempts of subordinates (since they could not fully control the m ating behaviour of the females they guarded), while among females there was little or no attempt to prevent subordinates from breeding (at least, prio r to parturition). Two within-group infanticides by males suggested that so me control over reproduction may be exercised postpartum Per capita survivo rship of young in the den increased with the number of females who gave bir th. Thus, dominant females may benefit from subordinate reproduction, provi ding a possible explanation for the lack of reproductive suppression among females in this species. (C) 2000 The Association for the Study of Animal B ehaviour.