Fear of humans by laying hens in different tiers of a battery: behavioural and physiological responses.

1. The behavioural and physiological responses of 128 laying hens from two tiers of a battery to a number of stimuli were compared. 2. Birds from the top tier showed greater avoidance of an approaching human and a novel object. No differences were found in a tonic immobility test. 3. Birds from the top tier showed a greater corticosteroid response to handling/blood sampling but there were no differences in plasma glucose or free fatty acid concentrations. 4. The findings are discussed in relation to other studies that ascribe similar behavioural responses to "general" fearfulness. However, it is argued that an equally valid interpretation of the data is a stimulus-specific fear response to humans.