Avian Mycobacteriosis in White-winged Ducks (Cairina scutulata)

摘要

The white-winged duck (Cairina scutulata) is a Southeast Asian species severely endangered in the wild and extinct in several countries.1 The main threat to these birds is loss of lowland tropical forest and locally intense hunting pressure.1 Recoveryefforts and ex-situ conservation include captive breeding at The Wildfowl and Wetlands Trust, Slimbridge, England and at the Sylvan Heights Waterfowl Center, North Carolina, USA. These breeding programs represent the only Anseriformes Species Survival Plan of the American Zoo and Aquarium Association. Currently there are fewer than 60 individuals in North America.2 Recovery attempts for this species have been jeopardized by its high susceptibility to mycobacteriosis.2'3 Reports from the Wildfowl and Wetlands Trust have shown that up to 84% of the white-winged duck deaths are the result of a mycobacterial infection.4'5 Mycobacterium avium avium serotype 1 has been reported as the causal organism for the deaths in these birds.4'5 Mycobacteriosis has also been recognized in white-winged ducks in the Sylvan Heights Waterfowl Center collection.2 However, the percentage of white-winged ducks that die with mycobacteriosis has not been reported, the gross and microscopic lesions in these birds have not beendescribed, and the mycobacterial species causing disease in them has not been identified. The cause of this apparently high susceptibility to mycobacteriosis is also not known, but it has been speculated that low genetic diversity, management-related problems, and environmental factors may all be predisposing factors.