Sociality and relationships in Alpine ibex (Capra ibex)

Abstract

Gregariousness, inter-individual and general patterns of association of adult ibex (Capra ibex) were studied outside the rut in 1988, and comparatively in 1988 and 1989 for males in a small population (Sous-Dine massif, French Alps). Females were less often alone, lived in larger groups albeit with fewer same-sex adults than males. As they aged, males were more often alone and lived in smaller groups, while typical numbers (see «typical group size » of Jarman, 1982) of males and of females were independent of their age. Females tended to be more with females than with males and most of them formed loose bonds. 1-2 year-old males associated with individuals of both sexes as expected by chance, whereas > 2 year-old males lived in groups where they clearly outnumbered females. The oldest males showed loose bonds with other males. Those 3-4 to 11-12 years old were seen less often than expected with either younger or older males, associated preferentially with individuals in the same age interval and formed close bonds among themselves resulting in relatively stable sub-groups. Males < 5 years old did not change their general patterns of association but did show weaker social bonds in 1988 than 1989. In contrast, > 4 year-old males tended to be alone more often and less in all-male groups in 1988, while their occurrence in female groups did not vary. Males > 4 years old also displayed more stable networks of association than younger males. Some pairs and sub-groups of males aged 2 to 11 years were consistent during the two consecutive years.