Padrões de comportamentos de um grupo de Alouatta Guariba Clamitans em um fragmento de mata nativa no município de Restinga Seca, Rio Grande do Sul

Abstract

It has been monitored the group behavior of brown howler monkeys (Alouatta guariba clamitans), in the municipality of Restinga Seca, Rio Grande do Sul, on a deciduous forest fragment which has approximately 15 hectares. The observations were conducted between February to September 2015. A total of 1,502 behavioral records were taken. Initially, the group were composed by eight individuals, two were adult male, three were adult female, one was young male, and two independent infants. The method used to collect behavior data was instant scan, which consists on observations for five minutes, with ten minutes break. In order to analyze the data it was used the frequency analysis, sociogram, similarity analysis and coordinate principals analysis. On the group activity pattern, the resting was preponderant (57%, n= 750); followed by feeding (24%, n = 317); displacement (16%, n = 213) and social interaction (3%, n =39). Basically, the diet were composed by leafs (88% = 51% of young leafs and buds + 37% of mature leafs), complemented by fruits (10% of mature fruits + 5% of immature fruits). There were differences of behavioral pattern over the year seasons. Probably, the behavior of each individual by age has a strong influence in the summer. Moreover, the behavior by gender difference can suffer influence during the winter and the spring. During the research it was possible to identify the dominant male, as well as, the subdominant male. Although the relativized results by a small n sample, they provided evidence of disagreement to the patterns described by Milton (1974).