Responses to novel foods in captive chimpanzees

Hesitancy to eat novel foods hampers the immediate enlargement of the diet
but serves to limit the risk of ingesting toxic foods. Neophobia has been
systematically investigated in only a few primate species and it seems
affected by social influences. Surprisingly, little is known about
chimpanzees' neophobia. We studied the response of 8 adult captive
chimpanzees to 16 foods (foods commonly eaten by humans and never tasted
before by chimpanzees). Each novel food was presented twice to the
chimpanzee by a familiar or an unfamiliar human. Between the two trials
the human ate the food face to face with the chimpanzee (demonstration).
Results showed that some foods were almost unanimously accepted whereas
others were not. Moreover, there were marked interindividual differences
in food acceptance and consumption; chimpanzees ranged from being almost
completely neophobic to accepting almost all foods. Familiarity with the
human and the human's demonstration did not affect responses to the foods.
Humans' predictions on chimpanzee's acceptance of the different foods were
rather good; furthermore, in 7 cases out of 8 the human's preferences did
not correlate with his/her predictions on chimpanzees' preferences. The
finding that most captive chimpanzees are initially cautious towards novel
foods supports the little information available for wild chimpanzees,
whereas the lack of influence of the human's familiarity and demonstration
on the response to food by chimpanzees calls for more naturalistic
studies, in which social influences are provided by group members. Since
novel stimuli provide sensory stimulation and elicit exploration and
social interest, occasional presentation of novel foods could be a
promising and cheap device for feeding enrichment.