The role of experience in the development of food preferences in gull chicks

Abstract

Experiments were carried out with captive herring gull and ring-billed gull chicks to determine the effect of restricted feeding experience on the formation of food preferences. Chicks were reared from hatching to 5 days of age on one of three regimens: (1) chopped earthworms, (2) pink cat food, and (3) green cat food. On the sixth day each chick was given a choice between its training food and one of the unfamiliar foods, and then a choice between the two unfamiliar foods. The training experience resulted in selection of the familiar food in fifty-three of sixty tests with herring gull chicks and in sixty-nine of seventy-two tests with ring-billed gull chicks. In the tests involving a choice between the two unfamiliar foods worms were preferred over pink cat food and this over green cat food. Three herring gull chicks and ten ring-billed gull chicks, however, failed to take any food, suggesting that lack of familiarity with a food material may be equivalent to non-recognition of that material as food. The results of these tests are considered in the light of Tinbergen's specific search image hypothesis relating initiation of feeding on a new food item with chance experience.