Abstract # 94:

Scheduled for Friday, June 20, 2008 05:00 PM-07:00 PM: Session 12 (Ball Rooms A and B) Poster Presentation

Tropical rain forest fragmentation and social interactions in young howler monkeys (Alouatta palliata)

C. Jasso and A. Estrada
Universidad Nacional Autónoma de México, Laboratorio de Primatología. Estación de Biologia Tropical, Veracruz, Mexico
     Habitat fragmentation affects demographic structure and the social environment available to young individuals in primate groups. However, social interactions of immature howler monkeys (Alouatta palliata) living in fragmented habitats have not been adequately documented. In this study we compared patterns of social interactions of non-adults in one group of howler monkeys in a continuous forest (>600 ha) to those in another group in a fragmented habitat (3.5 ha) in Los Tuxtlas, Mexico. During seven months, focal animal sampling (continuous habitat n=51 h; fragmented habitat n=37 h) was used to record the occurrence and time spent in social interactions by non-adults. Instantaneous scan sampling (continuous habitat n=1378; and fragmented habitat n=1773 scans) was applied to record inter-individual spacing between young and other individuals in the groups. Infants in the fragmented habitat spent more time in social play than infants in the continuous habitat [Mann Whitney U test, a=0.05]. Juveniles in the fragmented habitat engaged more in agonistic interactions than juveniles in the continuous habitat but these differences were not statistically significant. Infants and juveniles in the fragmented habitat had greater diversity of social partners at two inter-individual spacing measures (1m and >1m) than those in the continuous habitat [Mann Whitney U test, a=0.05]. The observed patterns in the fragmented habitat may be the result of adjustments by howlers to canopy discontinuity and sparser resources.