Abstract # 2731 Event # 91:

Scheduled for Sunday, September 20, 2009 09:45 AM-09:55 AM: Session 8 (Shell Room) Oral Presentation


DO FOREST COMPOSITION AND FOOD AVAILABILITY PREDICT DEMOGRAPHIC DIFFERENCES BETWEEN OWL MONKEY (AOTUS AZARAI) GROUPS INHABITING A GALLERY FOREST IN FORMOSA, ARGENTINA?

G. W. van der Heide1, D. Iriart2, C. P. Juárez1,3 and E. Fernandez-Duque1,3,4
1Fundación ECO, Droevendaalsesteeg 91, Wageningen, Gelderland 6708PS, The Netherlands, 2Universidad Nacional del Nordeste, 3Cecoal-Conicet, 4Dept. Anthropology, University of Pennsylvania
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The demographic parameters of a population tend to be influenced by habitat quality. We examined this potential relationship in a population of socially monogamous territorial owl monkeys. To characterize forest composition and food availability of four territories, we identified and measured the basal area of all feeding trees [n=3057, DBH>10cm] in 16 ha. We collected data on births and age at natal dispersal monthly between 1997-2007. Some abundant food species (e.g. Chrysophyllum gonocarpum) were unevenly distributed among territories; and some rare, but highly preferred ones (e.g. Tabebuia ipe), were absent in two territories. Winter food availability was lower in one territory than the others. In that territory, the number and total basal area of winter feeding trees [163 trees, 10.3 m2] was lower than in the other ones [223, 283, 253 trees, 14.1, 16.5, 19.2 m2]. The number of infants produced [8, 9, 9] and the mean age of natal dispersal were relatively similar among the 3 groups with complete records [3.1, 3.1 and 3.2 yrs, K-W test Χ2(3)=0.3, p=0.8]. The differences among territories in forest composition and food availability were not clearly linked to basic demographic parameters. In the future, we will need to examine food abundance during other times of the year, as well as differences among territories in tree species diversity.