Abstract # 196:

Scheduled for Saturday, June 23, 2007 11:05 AM-11:20 AM: Session 19 (North Main Hall C/D) Symposium

Fecal Cortisol Levels and Maintenance Behaviors in Wild Groups of a Cooperatively Breeding Species, The Red-bellied Lemur (Eulemur rubriventer)

S. Tecot
Department of Anthropology, University of Texas at Austin, 1 University Station, Austin, TX 78712, USA
     Grooming interactions and cortisol excretion were examined in Eulemur rubriventer throughout gestation to understand non-parental infant carrying. To test if olfactory cues through proximity were necessary to facilitate care-giving, all grooming interactions with pregnant females were predicted to increase through gestation. To test if caregivers responded hormonally to changes in female hormone levels during gestation, male cortisol levels (C) were predicted to follow a consistent pattern throughout gestation whereby elevations responded to female C elevations. All occurrences of grooming in focal animals were recorded continuously (n=2633hrs) for 18 months in 16 individuals (5 groups). Weekly fecal samples (n=375) were collected from focal animals (n=12) throughout gestation (20 weeks; 6 pregnancies). Reproductive week had no significant effect on grooming by age, sex, or prior infant experience. Using a mixed model with ‘week’ as the repeated measure, no differences in C were found by sex [F(1,19)=0.596, ns] nor by experience [F(1,19)=0.674, ns]. Week had a significant effect on all individuals’ C [F(1,19)=3.23, p<0.01] with peaks occurring during weeks 6, 11-12, and 16-19. Most males’ initial C elevations (n=6) occurred concurrently with the group’s pregnant female. Pairwise comparisons [a=0.05] revealed that significant elevations in female C occurred during week 6, and preceded all significant elevations in males’ C. Results indicate that care-giving is not related to changes in proximity, and may be stimulated by detectable hormonal changes in pregnant females.