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To evaluate the usefulness of restocking of grey partridge Perdix perdix in marginal ranges we studied survival, spring dispersal and breeding success of wild and released grey partridge females using radio‐tracking. Released females had lower survival during the breeding period than wild females. Within the limitation of the small sample size obtained from the released birds surviving till nesting, there was no difference in spring dispersal, nesting chronology, clutch size, and nest predation between wild and released birds. However, wild partridges produced more fledglings per radio‐tracked female than released birds. This difference was mainly due to the higher survival rates of wild hens compared to those of released hens before the incubation period. We conclude that due to their poor survival and reproduction output, released birds may have little value in attempts to boost threatened wild populations of the grey partridge, whereas habitat management and predator control could be more useful tools for the preservation of grey partridge populations in marginal regions.

Artificia l rearing may result in changes in the physiology and anatomy of gallinaceous birds. This may partially explain the poor survival of released birds. To study the effects of hand-rearin g on grey partridges Perdix perdix, we measured the anatomical and physiological characteristics of 14 wild and 15 hand-reared partridges. Captive partrid ges were heavier, had relatively larger breast muscles but relatively lighter hearts and livers than wild birds. Wild birds had longer small intestines, longer caeca and relatively heavier gizzards than hand-reared birds. They also had higher glycogen content and cytochrome-c oxidase activity in the pectoral muscles, indicating their better flying endurance compared to hand-re ared birds. The results suggest that captivity results in altered anatomical and physiological characteri stics, and hand-reared partridges may therefore be poorly predisposed for an abrupt release into the wild.

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