Demography of Owl Monkeys (Aotus azarai) in Pilcomayo National Park (Formosa, Argentina)

CECILIA PAOLA JUÁREZ; EDUARDO, FERNANDEZ-DUQUE

Mendoza, Argentina

Congreso; 10th International Mammalogical Congress.; 2009

CONICET, IADIZA,GiB,SAREM

The conservation status of owl monkeys in Argentina is largely unknown.  The only protected populations are found in Pilcomayo National Park in the Province of Formosa.  We conducted a preliminary evaluation of the species in the park during 2007-2008. Our goals were to conduct a qualitative evaluation of the owl monkey population in Pilcomayo National Park, to quantify basic demographic parameters (group size and age structure) of it and to compare it with the well-studied population from Guaycolec Ranch, Formosa. Demographic data were collected from the 16 social groups in the gallery forest along the Pilcomayo River and in 9 patches of forest immersed within the park’s savannahs. Individuals (n=86) were assigned to the different age classes (adult, juvenile, independent infant, or dependent infant) based on their relative size when compared to other members of the group.  The owl monkey groups ranged in size between 2 and 5 ind/ groups. There were 16% of infants, 18% of juveniles and 59 % of adults.  The remaining individuals (6%) are unknown individuals. Comparatively, preliminary results suggesting that patches of forest contain groups smaller than gallery forest (2.4 vs. 3.3 ind/groups). The Owl Monkeys in Pilcomayo National Park was not significantly differences with the population studied since 1997 in a private ranch.