Causal factors of stereotypies in caged birds

Abstract

Two repetitive avian stereotypies, spot-picking and route-tracing, are examined with respect to the factors which cause the onset of these behaviours. Stereotypies were counted in 5-min observation periods, excluding time spent singing, feeding, drinking, or preening. Twelve of these 5-min periods made up an experimental test series. Several experiments were conducted to determine the effects of various environmental and developmental conditions on the frequency of stereotypies. Route-tracing was reduced in a very large aviary cage and when a swinging-perch arrangement was added to a smaller cage. Spot-picking was reduced when canaries were required to ‘work for food’. Wild-caught birds generally exhibited a greater number of route-traces and few if any spot-picks when compared to laboratory-reared birds, although the type of laboratory rearing (isolated, grouped, mother-reared, hand-reared) seemed to have little effect. It is therefore suggested that route-tracing is associated with the physical restrictions imposed on movement by the cage, while spot-picking results from some deficiency associated with laboratory conditions.