Comparison of the social behaviour of captive sympatric peccary species (genus Tayasuu); correlations with their ecological characteristics

Comparison was made of the social behaviour of two congeneric peccary speci es, the white-lipped (Tayassu pecari) and the collared peccary (T. tajacu), coexisting in South American rain forests and observed in captivity. In th e former species, herd cohesion is strong, and strangers generally are viol ently attacked. White-lipped peccaries have 2-3 times more contacts with pa rtners of their herd than collared peccaries. In many social behavioural si tuations, the dominant female is the most active individual in the white-li pped peccary herd, whereas the dominant male is the focal member of the soc ial unit in the collared peccary. Subordinate and subadult males participat e in all social behaviour, including sexual, and are very well integrated i nto the white-lipped peccary herd. In contrast, subordinate collared peccar y males are more or less neutral and peripheral individuals. Unlike the lat ter species, aggressiveness is noticeable in most behaviour of the white-li pped peccary; the dominant male is the main effector of these agonistic con tacts, which are frequent and intense. In this species, both sexes belong t o only one hierarchic order, with males always superior to females. Convers ely, in the collared peccary, there are two distinct monosexual hierarchic orders, and the females dominate the males. These interspecific differences , as well as the total lack of ground marking in the white-lipped peccary, fit well the ecological characteristics of both species: the white-lipped p eccary lives in wandering, Large multiple-male herds, and the collared pecc ary in small stable and locally resident troops.