FOOD SHARING IN LION TAMARINS - TESTS OF 3 HYPOTHESES

Infant marmosets and tamarins (Callitrichidae) frequently receive food from older group members. Three possible functions of food sharing in lion tamarins were examined experimentally. The first hypothesis, tha t food sharing ensures that infants receive sufficient food even if it is difficult for them ts acquire it themselves, was tested by varying the ease with which infants could reach a food source. When access to food was restricted, infants fed themselves less, received more food from others, and had a higher success rate in begging attempts. The se cond hypothesis, that food sharing helps teach infants an appropriate diet, was tested by presenting fruits that were novel to infants. Alth ough infants fed themselves less under these conditions, adults were l ess likely to share novel foods than familiar foods. The final experim ent compared food sharing when food was abundant with behavior when fo od items were presented singly. Infants fed themselves less and receiv ed more food from others when food items were rare. These results sugg est that food sharing in lion tamarins helps to ensure that infants re ceive adequate amounts of food which is difficult to locate or acquire , but that it is not involved in teaching infants which foods they sho uld eat. (C) 1993 Wiley-Liss, Inc.