Male pigeons react differentially to altered facial features of female pigeons

Male pigeons exhibit robust courtship to the head of a female, but not so much to the body. The specific features in the female head which are critical for triggering courtship from males remain unclear. We examined this issue by studying preference behaviour of male pigeons between a pair of photographic images of female conspecifics: a series of normal female faces and a series of digitally altered facial features. Preference was determined by measuring the duration of male courtship 'coo' responses near each of these images. Males preferred intact females compared to those missing the eyes and beak. They also responded less when only the eyes and beak were visible without the head, suggesting that these local features were important, yet more effective when embedded in the context of the head than when they were not. Enlarging or removing the beak had a significant impact on preference, whereas manipulating the eyes had a weaker effect. Finally, males exhibited no preference between normal females and those that had spatially rearranged eyes and beak. These results suggest that pigeons naturally attend to the local features of the head, but not to the spatial configuration, for conspecific recognition.