Distance and Social Recognition in Hens: Implications for the Use of Photographs as Social Stimuli

Abstract

AbstractThe role of close (less than 30 cm) examination or scrutiny of other birds in social recognition was confirmed by showing that before approaching a hen whose identity was unknown, hens behaved similarly whether that bird was familiar or unfamiliar to them, but after examining the other hen they temporarily kept further away from unfamiliar hens (Expt 1). Hens chose flock-mates rather than unfamiliar birds as feeding companions even when all that was visible of the target birds were their heads and necks, confirming the role of these regions in recognition (Expt 2). They showed this preference for familiar birds whether they could see either the front or the side views of the heads of the target birds but attempts to confirm this result with photographs rather than live birds resulted in no significant preference being shown (Expts 3 and 4). The reasons for this lack of transfer from live birds to photographs and its implications for presenting artificial visual stimuli such as photographs and video to hens are discussed.