"Self-awareness" in the pigeon

Science. 1981 May 8;212(4495):695-6. doi: 10.1126/science.212.4495.695.

Abstract

Each of three pigeons used a mirror to locate a spot on its body which it could not see directly. Although similar behavior in primates has been attributed to a self-concept or other cognitive process, the present example suggests an account in terms of environmental events.