Abstract # 3076 Event # 241:

Scheduled for Monday, September 19, 2011 03:30 PM-03:45 PM: Session 34 (Salon F (Sixth Floor)) Oral Presentation


A LAB-FIELD APPROACH TO ESTIMATING THE ENERGETIC COSTS OF BIPARENTAL CARE IN OWL MONKEYS

E. Fernandez-Duque1,2,3, S. Evans4 and M. Emery-Thompson5
1University of Pennsylvania, 431 University Museum, Department of Anthropology, 3600 South Street, Philadelphia, Pennsylvania 19104, USA, 2Fundacion ECO, 3Centro de Ecologia Aplicada del Litoral (Conicet-Argentina), 4DuMond Conservancy for Primates and Tropical Forests, 5Department of Anthropology, University of New Mexico
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Owl monkeys live in monogamous groups including one pair of adults and a few young. Adult males transport infants, share food and play with them more frequently than do mothers. The intense paternal care may have evolved because it lessens the energetic costs of female reproduction. We evaluated a lab-field approach for quantifying energetics using dependent variables that can be measured only in the lab (C-peptide), or in both lab and field (activity, body mass). We fitted one adult male and one adult female with accelerometer collars that continuously recorded their activity while housed in an 8 m3 cage (3 weeks) or a 2.8 m3 cage (2 weeks). We weighed the subjects at the beginning and end of the study and we collected urine samples three times a week (female=17, male=18). There was more activity in the larger cage, whereas C-peptide levels were higher in the smaller cage (male: 411±269 vs 314±117, female: 863±659 vs 329 ± 141). Individuals gained weight (female: 971 to 1129 gr; male: 713 to 742 gr). The reduced activity in the smaller cage resulted in a positive energy balance as reflected by increased higher C-peptide values and weight gain. A lab-field approach can qualitatively change our understanding of the mechanisms used by male and female owl monkeys to satisfy their energetic demands.