The Ontogeny of Anti-predator Behaviour in Game Bird Chicks.

Abstract

Captive-reared game birds escape from predators less efficiently than their wild counterparts and this may be due to impaired predator avoidance behaviour as a result of the absence of parents during the rearing process. This hypothesis was investigated in grey partridges Perdix perdix and common pheasants Phasianus colchicus by tracing the ontogeny of their anti-predator behaviour.

Conspecific family groups of up to 21 grey partridges and pheasants were reared from hatching either with conspecific parents, with domestic bantams Gallus domesticus as foster parents or intensively, without parents. Parent-reared partridge and pheasant chicks developed more appropriate anti-predator responses to models of an aerial predator and tape recordings of conspecific and bantam alarm calls than those of bantam-reared and intensively-reared chicks.

Two hundred grey partridges were released onto agricultural land in Dorset in 1987 and 1988. Their behaviour and survival was compared with that of wild grey partridges in the release area. Mortality of released grey partridges was four times greater than that of wild birds in the first 25 days after release. Over-winter losses of released birds from the study area were over 90%. Post-release behaviour of captive-reared partridges was similar to that of wild grey partridges, except that intensively-reared birds were reluctant to move away from hedgerows and trees at field margins, making them more vulnerable to predators.

The results are discussed in terms of their application to improving methods of rearing game birds for commercial restocking and for reintroduction into areas of their former range.