Most feather pecking occurred between birds in the same cage rather than between birds in neighbouring cages during both morning (81%) and afternoon (92%) observations. 2. In the afternoon feather pecking and cage pecking were respectively 3.6 and 4.4 times more prevalent than in the morning. The proportion of severe feather pecking (19%) was unaffected by time of day. 3. These findings are discussed with regard to the possibility that feather pecking in the afternoon may reflect attempts by hens to adapt to an unstimulating environment and the limited potential for control of feather pecking by modification of the design of conventional cages, unless between--cage transmission of the behaviour is important in the development of feather pecking.
