Behavioural Parameters of Vigilance in the Dwarf Mongoose: Social Acquisition of a Sex-Biased Role

Abstract

Dwarf mongooses live in matriarchal family groups and possess a highly complex coordinated vigilance system. Parameters of vigilance bchaviour such as guarding duration, frequency, sequence, cues mediating guard orientation and exchange, number of guards present and fidelity to guarding sites are described for wild groups and compared, where appropriate, with data from captive ones to determine whether vigilance becomes modified after generations in captivity. Wild and captive groups showed little difference in basic guarding behaviour. Vigilant animals utilise a complex system of vocalisations to indicate predator presence, these varying with the type of predator sighted and mediating group response, which differs with predator type. Guarding is performed almost exclusively by subordinate males in both captive and wild groups. Vigilance behaviour is absent in naive hand-raised animals kept either singly or in pairs and put together in a group at approximately 1 year old. It develops normally, however, in the young of groups containing experienced adults. Several of its characteristic behavioural parameters are postulated as being acquired during juvenile/adult association at guarding sites. The implications of these findings are discussed.