Effects of reproductive states on feeding patterns of black and gold howlers (Alouatta caraya) females

PÉREZ-RUEDA, M.A.; CANTARELLI, V.I.; PAVÉ, R.E.; KOWALEWSKI, M.M.

Congreso; XIV Congreso Brasileiro de Primatología; 2011

Reproductive states involve high nutritional requirements for female primates and may influence on their feeding patterns. Lactation is considered the most energetically expensive part of mammalian reproduction. In order to compensate the nutritional cost of lactation, female primates generally increase their nutritional intake, consuming more high-quality food items, or spend significantly more time foraging than non-lactating females. The objective of this study was to determinate whether the female reproductive state in wild Alouatta caraya is associated to fluctuations in feeding patterns. It took place in two nearby sites in Northeastern Argentina, one was a flooded forest in Isla Brasilera, Chaco province (27° 20´ S; 58° 40´ W), and the other site a gallery forest in mainland northwestern Corrientes province (27° 30´ S; 58° 41´ W). Between September 2009 and February 2010, we collected data from 22 adult females and 10 adult males belonging to 8 groups of black and gold howler monkeys, using a 2-min scan sampling technique, and completing a total of 720 h of observation. We compared the time dedicated to feeding between females in different reproductive states (gestating, lactating, and cycling), and between adult females and males. We found that lactating females spent significantly more time feeding than gestating or cycling females (Kruskal ? Wallis Test, H (2, N= 18) = 6.87, p < 0.05). When we compared lactating females with adult males, the feeding frequencies were also higher for females during lactation (Kruskal ? Wallis Test, H (1, N= 12) = 6.58, p < 0.05). This results show a possible dietary adaptation to reproductive costs in Alouatta caraya females, indicating that lactation is the energetically most demanding reproductive state.