Food sharing in pied bare-faced tamarins (Saguinus bicolor bicolor): Development and individual differences

We investigated food sharing behavior in 5 litters of pied bare-faced tamar ins (Saguinus bicolor bicolor)-8 infants, from 3 families-from 5 to 26 week s of age, The frequency of sharing by parents in response to infant begging increased steadily from the age of 5 weeks to 16 weeks, and then declined. Offering of food by adults without prior infant begging occurred at very l ow frequencies throughout observations (1.5% of total items transferred). O n average, infants received approximately equal amounts of food from transf ers from others and by self feeding until about 20 weeks, after which self feeding began to predominate, Begging success-the proportion of infant begs which resulted in food sharing-remained relatively constant over rime, at 60-70%. Overall, therefore, the frequency of food sharing seemed to be gove rned by changes in infant rather than adult behavior. There were individual differences between adults in their response to infant begging, but two of three fathers transferred significantly more food to infants than mothers did. The results of this study emphasize the existence of specific and indi vidual differences in food-sharing behavior, which must be taken into accou nt in explaining its importance in the reproductive strategies of the Calli trichidae.