The Effects of Crowding on the Social Relationships and Behaviour of the Dwarf Mongoose (Helogale undulata rufula)

Since dwarf mongooses in captivity show an extremely stable familiar structure with no evidence of group break-up, the study was designed to place the animals under crowding stress to determine whether such tendencies would be manifested and whether compensatory mechanisms to maintain group cohesion are present. A stable family group of 12 animals was investigated and observations over 150 h under control and 120 h under crowded conditions made. The results show that social pressure is mainly exerted on subordinate adult ♂♂ and ♀♀, sometimes resulting in their death by stress-induced uraemia, through increased aggression by the a pair. The social system stabilises after 16 days but high intra-group aggression/submission remains. Synchronisation of oestrus cycles in nubile ♀♀ resulted in simultaneous littering with loss of all young. The significance of these findings for population regulation is discussed.