THE ROLE OF THE ALPHA MALE IN GROUP COORDINATION IN CAPUCHIN MONKEYS (CEBUS APELLA NIGRITUS) IN IGUAZÚ NATIONAL PARK, ARGENTINA

TUJAGUE, MARÍA PAULA; SCARRY, CLARA JOAN

Sacramento, california

Congreso; 35th Meeting American Society of Primatologists; 2012

ASP

Coordination of group movements is believed to emerge from decisions of key individuals, which are accepted and mimicked by other group members. Yet identifying these ?leaders? is frequently problematic. Here we examine therole of the dominant male on the coordination of group movements among tufted capuchin monkeys (Cebus apella nigritus) in Iguazú National Park, Argentina. In November 2009, intense intragroup aggression resulted in the death of the dominant male with no clear successor in the subsequent one-month period. During this period of instability, we recorded the location of the group?s center at 15-minute intervals (n = 1011 locations) and spatial position of focal individuals. In order to examine the effect of the dominantmale on group movements, we compared data from the period immediately following the death of the dominant male to matched-samples collected during the same season in 2007(n = 641 locations) and 2008 (n = 700 locations). During the period of male hierarchy instability, the group exhibited erratic movements and frequently formed subgroups. The data sets showed a significant difference in the distribution of changes in travel direction (Watson?s test of homogeneity: P < 0.001). Immediately following the death of the dominant male, directed forward movement (90 degrees) increased. These results suggest that, despite maintaining a central spatial position, the alpha male is a key factor in coordinating group movements.