Behavior, ecology and demography of owl monkeys (Aotus vociferans) in Yasuní National Park, Ecuador

Given its broad geographical distribution, the genus Aotus provides a rich ground for comparative studies that evaluate how different ecological factors influence the morphology, behavior, ecology and demography of closely related species. During 18 months we collected demographic, ranging and activity data from owl monkeys (Aotus vociferans) in Yasuní National Park in eastern Ecuador. To collect demographic data, we monitored the trail system several times per month searching for groups. To characterize patterns of activity, we recorded the time when the animals began and ended their nocturnal activity, and we collected data on range use and daily path length during 12 full-moon and 12 new-moon night follows of one radiocollared group. Owl monkey groups ranged in size between three and five individuals (n=4 groups). All groups were strictly nocturnal, beginning their activity between 1800 and 1900h and finishing it between 0500 and 0600h. The territory size of the radiocollared group was 6.3 ha. On average, the animals traveled 645 m per night (± 280 m) and ranged farther on nights of full moon than nights of new moon. The animals used a small number of preferred daytime sleeping trees. Our data conform well with what has been reported in studies of other tropical owl monkeys from Colombia and Perú. A comparison of tropical owl monkeys with more temperate Aotus azarai from the Argentinean Gran Chaco reveals that grouping patterns, day range length, and territory size are relatively conserved across the genus despite dramatic differences in body size and activity pattern. Behavior, ecology and demography of owl monkeys (Aotus vociferans) in Yasuní National Park, Ecuador Eduardo Fernandez-Duque , Anthony Di Fiore 3 and Gabriel Carrillo-Bilbao 4 1 Department of Anthropology, University of Pennsylvania, USA 2 Centro de Ecología Aplicada del Litoral, Conicet, Argentina 3 Center for the Study of Human Origins, Department of Anthropology, New York University 4 Estación Científica Amazónica, Universidad Central del Ecuador Short title: Behavior and ecology of Ecuadorian owl monkeys Eduardo Fernandez-Duque 431 University Museum Department of Anthropology University of Pennsylvania 3260 South Street Philadelphia, PA 19104 Phone: 215-898-1072 Fax: 215-898-7462 Abstract, 250 words