Emesis in birds.

Comparative studies of emesis in the herring gull, pigeon, chicken, and cowbird were conducted, using orally administered copper sulfate and intravenously administered copper sulfate, hydergine, apomorphine, and lanatoside C. A response to every emetic was elicited from some birds. However, the individual and species differences among the birds were as great as those among mammals. Further, the response of the avian species studied did not indicate that any of them could be used to predict how a specific mammal would react. The differences in response to the emetics by the birds do not offer any simple pattern related to feeding behavior.