Capture techniques and morphometrics for the woolly spider monkey, or muriqui (Brachyteles arachnoides, E. Geoffroy 1806)

A total of 12 free-ranging muriquis (Brachyteles arachnoides) were captured with Telazol® at Fazenda Esmeralda, Minas Gerais, Brazil, and at Fazenda Barreiro Rico, São Paulo, Brazil. All animals were measured, marked, weighed, and released. Previously reported data suggested that Brachyteles is a sexually dimorphic species with female-male body weights of 12-15 kg, respectively. We found no statistically significant difference in body weight between females (mean = 8.4 kg, range = 6.9-9.3 kg, n = 4), and males (mean =9.6 kg, range = 9.3-10.2 kg, n = 4). Our results are at variance with previously published body weights in the literature. Larger sample size may reveal a significant sexual difference, particularly in body weight.