This paper examines the developmental causes of feather pecking, a common behaviour in caged chickens that leads to extensive feather damage. Small groups of junglefowl, Gallus gallus spadiceus, were raised from hatching either on a substrate containing sand and sod or on one consisting of wire mesh. Observations of social and other behaviour were made between 2 and 9 months of age. Feather pecking was most likely to occur when the birds were dustbathing or showed intention movements of dustbathing. Futhermore, the number of severe feather pecks received during dustbathing was correlated with the amount of feather damage on the recipient. The birds that did the most feather pecking were the ones found to be most fearful as assessed by a test of tonic immobility, and additionally the ones participating least during dustbathing in their group. Allopreening pecks could be distinguished from feather pecks: Allopreening pecks were directed entirely at the anterior part of penmates and were gentle, while feather pecks were directed at the lower part of penmates and were often severe. Both were related to social status: Lower ranking birds showed more allopreening while higher ranking birds showed more feather pecking. Sometimes, however, lower ranking individuals showed feather pecking in allopreening situations. The environment in which birds are reared may be significant for the development of feather pecking, and it is suggested that the primary cause of feather pecking is an abnormal development of the perceptual mechanism responsible for the detection of dust for dustbathing. © 1993 The Association for the Study of Animal Behaviour. All rights reserved.
