Preparing captive-bred birds for reintroduction: the case of the Vietnam Pheasant Lophura edwardsi

Abstract

SummaryThe Vietnam Pheasant Lophura edwardsi (including L. hatinhensis) is only known from a small area of central Vietnam, where it occurred in wet forest below 300 m. It is probably extinct in the wild, but some 1,500 birds, derived from 28 individuals caught in 1924–1930, survive in captivity. Guidelines for reintroducing galliforms date from 2009. Subsequent literature was reviewed for new research findings to help maximise the chances of success in reintroducing birds. Studies confirmed that non-parent-reared captive-bred galliforms survive poorly, primarily owing to inadequate anti-predator responses. These reflect both genetic and ontogenetic unsuitability to wild conditions, with progressive maladaptation of stock being related to the number of generations spent in captivity (at least 35 in the case of Vietnam Pheasant). To compensate as far as possible for this deficiency, a reintroduction programme should use: environmental enrichment (including the provision of perches in aviaries), dietary enrichment (especially involving practice with live food), parent-rearing over several generations (although how many are needed for a species almost a century in captivity is unknown), soft releases (allowing full familiarisation with the future environment over at least 50 days), rigorous anti-predator training (against both air and ground attacks), anti-predation release stratagems (relocating and deterring predators, releasing birds at several stations, offering post-release support), determining appropriate numbers (per batch, with at least 300 in total per site) and time-frame for release (around five years) and the selection of fully suitable releasees in (as far as possible) naturally formed social groups, including parent-guided offspring aged around four months. Six sites need survey for extant populations or use for reintroduction, and the choice of reintroduction site will depend primarily on habitat extent and condition. The costs of these measures will be high and the overall project schedule will need to extend beyond the overall five years currently planned.