Variação sazonal e longitudinal na ecologia do guariba-de-mãos-ruivas, alouatta belzebul (Primates, Atelidae), na Fazenda Pacatuba, Paraíba

Abstract

The present study focused on the behavioral ecology of a group of red-handed howlers, Alouatta belzebul, which inhabits a fragment of Atlantic Forest habitat in the northeastern Brazilian municipality of Sapé, Paraíba. In particular, it was hoped that the study would contribute to the conservation of the species in this region of Brazil. A study group of 19 individuals was monitored for seven months (August-October, 2011, and January-April, 2012), with monthly visits of five complete days (sleep-tree to sleep-tree). Quantitative behavioral data were collected in one-minute instantaneous scan samples at intervals of 10 minutes. All-events sampling was used to record rare behaviors, in particular social interactions. Based on scan sample records, resting was the predominant activity (67.8% of records), followed by feeding (13.7%) and locomotion (12.0%). Significantly higher levels of resting were recorded during the dry season, whereas feeding and resting increased significantly during the rainy season. The diet was folivorous-frugivorous, with a small proportion of flowers. The consumption of leaves increased significantly during the dry season, and that of fruit during the rainy season. The study group occupied an estimated home range of 10.25 hectares, although a much smaller area was used during any given month. Mean daily path length was 573 m (range: 276-1179 m), with shorter paths being recorded during the dry season and periods of increased folivory. In comparison with previous studies at the site, some considerable differences were observed in parameters such as the composition of the diet, while others, such as home range size, were relatively stable. Overall, the availability of feeding resources within the group s home range appeared to be the principal factor determining variations in the activity budget, ranging patterns, and the composition of the diet, as well as longitudinal patterns in the ecology of the species at the study site.