Box, H. O., Smith, P. 1995. Age and gender differences in response to food enrichment in family groups of captive marmosets (Callithrix, Callithrichidae). Animal Technology 46, 11-18.

The proximity of individual members of three family groups of marmosets was measured to two sources of food namely, on the introduction of their normal daily ration (baseline behaviour) as well as to a previously unfamiliar 'preferred' food [grapes]. Significant group and age differences were found in the baseline condition in which the adults and the youngest recorded animals were most responsive to the food. A significant gender difference was also found in that females were significantly more responsive to their normal food during the period in which the additional food was given. Moreover, there was a significant change in behavioural responsiveness over the duration of the experiment in that females became more responsive to the additional food. There was no evidence of overt aggression or behavioural exclusion from the food.