SOCIAL INHIBITION OF MOVEMENT IN DOMESTIC HENS

The possibility that laying hens, Gallus gallus domesticus, limit their movements in order to minimize the number of high-ranking or unfamiliar birds encountered was investigated. Two experiments measured the time taken by individual birds to move past other birds in order to reach a preferred area. Birds were trained to move out of a small, empty cage (cage 1), down a runway and into a larger cage containing food, water and shavings (cage 2). In experiment 1, a third cage (cage 3) protruded into the runway. In the four treatments, cage 3 contained a dominant bird, a subordinate bird or an unfamiliar bird, or was empty (control). Compared with the other three treatments, birds took significantly longer to enter cage 2 when cage 3 contained an unfamiliar bird. In experiment 2, there were four middle cages in order to vary the number of unfamiliar caged birds (0, 2 or 4) which the test bird had to pass. Test birds took longer to enter cage 2 as the number of caged birds that they had to pass increased. Thus, social factors appeared to influence the movement of individual birds in this small-scale experimental situation.