Differences in wing shape of captive, critically endangered, migratory orange-bellied parrots Neophema chrysogaster relative to wild conspecifics

Abstract

Living in a captive environment may compromise phenotypic traits critical to survival in the wild. Captive animals that differ from the ideal wild phenotype may have impaired fitness after release, especially if there is extreme phenotypic selection during some life history stages. Wing shape of migratory birds is crucial to migration efficiency, and changes to wing shape in captivity may severely affect survival after release. We investigate wing shape of migratory Orange-bellied Parrots Neophema chrysogaster in captivity and the wild. The first two flight feathers were shorter in captive birds, and the fifth and sixth feathers were longer than wild conspecifics. These differences altered wing shape, producing a more proximal tip and a more convex trailing edge than the wild phenotype, which likely alters flight performance. This wing shape contravenes expectations from general patterns of wing shape in migratory birds. Wing shape in the captive birds sampled was independent of inbreeding, generations in captivity and ancestry. Captive environments may affect feather development or impose some selective pressure on wing shape. Alternatively, release from intense phenotypic selection during migration may allow parrots with wing shapes poorly adapted to migration to survive and breed in captivity. Altered wing shape may contribute to low observed survival of parrots released to the wild.