Abstract # 101:

Scheduled for Friday, August 19, 2005 10:30 AM-10:45 AM: Session 7 (Parliament Room) Oral Presentation

Eating for Two? The Effect of Reproductive State on the Diet and Nutrition of Free-Ranging Female White-faced Capuchins (Cebus capucinus) in Costa Rica

G. McCabe and L. M. Fedigan
University of Calgary, Dept. of Anthropology, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
     Lactation is considered the most energetically expensive state for females. Prior studies have found that nursing mothers have higher rates of energy intake or spend more time feeding than either pregnant or cycling females due to the costs of infant care. Our study examined the feeding patterns and nutritional composition of female white-faced capuchin diets at Santa Rosa National Park, Costa Rica. We observed 12 adult females for seven months, encompassing both wet and dry seasons. We collected focal animal data on foraging behaviour and analyzed food items consumed for levels of fat, protein, sugar, fibre, and energy. Results indicated that females in all three reproductive states (cycling, pregnant, lactating) fed for similar proportions of their activity budget (16-20%), but lactating females ingested food at significantly higher rates (P = 0.03). There were no clear differences in nutritional composition of their diets or food items eaten, except that lactating females ate a greater proportion of fruit compared to cycling females in the wet season (P = 0.037). Lactating females were found to have a higher energy intake in both seasons. These findings support the idea that milk production and constant care of dependant infants creates an energetically costly situation for mothers, requiring them to take in more energy. Capuchins may do this through faster ingestion rates as opposed to more time spent feeding, to keep up with group movements.