SEASONAL-VARIATION IN GROUP-SIZE OF CANTABRIAN CHAMOIS IN RELATION TOESCAPE TERRAIN AND FOOD

The herd size of Cantabrian chamois Rupicapra pyrenaica parva (Cabrera , 1910) varied seasonally in relation to escape terrain and food avail ability in our study area (Asturias, north of Spain). The median group size of females without kids was 1 (mean +/- SD = 1.62 +/- 1.00), fem ales with kids was 4 (5.59 +/- 5.42), males was 1 (1.73 +/- 1.78), and mixed group size was 7 (8.91 +/- 7.91). The female-kid group size dep ended more on escape terrain availability than on food quality. Throug hout the early weeks of the life of kids, the mothers remained in diff icult access areas (cliffs and steep slopes), and showed a weak tenden cy to aggregate. These areas provided a wide visual range and hiding p laces for offspring and their use may be an anti-predation strategy. W hen the kids were able to run quickly, the mothers used subalpine mead ows. These areas were very open and exposed kids to predation and huma n disturbance, however the forage has high nutritive value, and may co mpensate for the cost of breeding and suckling by the mothers. Aggrega tion may be selected as an anti-predation strategy in subalpine meadow s, allowing a reduction in time spent vigilant by each individual in t he group, and increased time available for other activities. The large st male groups were located in pastures with abundant but poor quality forage. Our results suggest that group size in Cantabrian chamois is very flexible, changing seasonally and in response to resource availab ility.