Social communication with food in captive common marmosets (Callithrix jacchus)

My Master Thesis is supervised by Prof. Klaus Zuberbühler from the University of Neuchâtel.  I investigated the food-associated behaviours in captive common marmosets (Callithrix jacchus). I have focused on one family, a breeding pair with 3 sets of twins, at Parc Challandes, a refuge for lost and abandoned animals, in Bellevue, near Geneva (Switzerland).

Previous studies revealed that infant common marmosets have a high level of interest on novel food and are begging for it. Moreover, adults transferred at the same level palatable and unpalatable food to their infants (novel and familiar). Thus, food transfer is valuable for infants to develop new cues and learn to accept novel food. It is well known that social learning occurs at an early stage of life, but no studies have been conducted on the development of individual knowledge about food in infants. Here, I was interested to find out if juveniles could have their own knowledge about familiar food and when they are learning about novel food. To address these questions, I recorded all behaviours of juveniles and their parents under 4 experimental conditions. 

I conducted 42 sets of experiments with palatable and unpalatable food (adding some bitter to the palatable food). Moreover, I chose to use 4 familiar types of food (fruits) and 4 novel food types (colored bread). The 4 experimental conditions are designed to use all combinations on the parents and infants. For example, in the first condition, the infants would experience unpalatable food while their parents would experience palatable food. Therefore, the prediction was, that if juveniles would eat the food presented, they have an individual knowledge but if they would avoid the food, social learning occurs. I was also interested in knowing if the age of infants, the presence of audience and the type of food had an influence on food transfer.