SOCIALITY AND RELATIONSHIPS IN ALPINE IBEX (CAPRA IBEX)

Jean-Charles VlLLARET* & Richard BON**

Introduction

There are conflicting results as to whether ungulate group composition is shaped by ecological factors or whether intrinsic factors play a role. Except in elk (Cervus canadensis) (Franklin & Lieb, 1979; Jenkins & Starkey, 1982) and African elephants (Loxodonta africana) (Moss & Poole, 1983), no permanent associations are known among non relatives adults (Leslie & Douglas, 1979; Boyd, 1981; Singer & Doherty, 1985; Hillman, 1987; Lawrence, 1990; Festa-Bianchet, 1991; Richard-Hansen, 1992). Associations among individuals would result from co-occurrence and successive encounters at attractive ecological points within overlapping home ranges (Lott & Minta, 1983; Lawrence & Wood-Gush, 1988). According to Lawrence (1990), sociality in sheep is based on a general gregariousness rather than on specific social bonds. Festa-Bianchet (1991) proposed that the bighorn sheep (Ovis canadensis) social system has been “shaped by antipredator and foraging strategies that rely on learned traditions”.

Le Pendu et al. (1995) found that mother and daughter can maintain a strong link in mouflon (Ovis orientalis). Although cows in bison (Bison bison) and chillingham cattle (Bos taurus) do not form permanent associations, females close in rank were more likely to interact, and to be nearest neighbours and groupmates (Lott & Minta, 1983; Hall, 1986). Bouissou & Hovels (1976) also showed that familiarity between heifers resulted in less agonistic interactions, more time feeding, in spatial associations and formation of subgroups of familiar animals. Predator detection and time spent foraging is reduced as group size increases (Berger, 1978; Alados, 1985; Risenhoover & Bailey, 1985). Therefore, female fitness would be enhanced by stable associations and familiarity.

Males were reported to live in loose groups in elk (Alces alces) and red deer (Cervus elaphus) (Franklin & Lieb, 1979; Clutton-Brock et al., 1982; Jenkins & Starkey, 1982). But they were more sociable in white tailed-deer (Odocoileus virginianus) (Hirth, 1977) and lived in more stable groups than did females in Soay

Rev. Ecol. (Terre Vie), vol. 53, 1998.