Activity budget and behavioural patterns of free-ranging yellow-tailed woolly monkeys Oreonax flavicauda (Mammalia: Primates), at La Esperanza, northeastern Peru

The critically endangered yellow-tailed woolly monkey (Oreonax flavicauda) is endemic to the cloud forests of north-eastern Peru and one of the least studied of all primate species. We conducted fifteen months of group follows using focal animal sampling techniques to gather the first behavioural data on free ranging O. flavicauda. Group follows took place in an area of disturbed primary and regenerating secondary forest near the village of La Esperanza, Amazonas department. Yellow-tailed woolly monkey activity budgets at La Esperanza average: 29.8% feeding, 26.3% resting, 29.0% travelling, 2.3% in social and 12.8% in other activities. Significant differences were observed in the frequency of behaviours between age/sex classes as well as on temporal scales. Our findings are similar to those of other woolly monkey species although yellow-tailed woolly monkeys were found to be more vocally active then other species. We recommend further study of this species at other sites with different forest types to better understand its behavioural ecology and conservation needs. Particular emphasis should be given to studying this species at different altitudes.