Abstract
The prevalence of beak and feather disease virus infection in wild populations of parrots and cockatoos in New Zealand
METHODS: Eastern rosellas (Platycercus eximius, n=162) were caught from Te Puke, Wellington and Dunedin, using mistnets, between April 2004 and February 2006, and sulphurcrested cockatoos (Cacatua galerita, n=255) were captured for pet-trading from November 2001 to September 2004. Feathers from both species were tested for BFDV, using an established polymerase chain reaction (PCR) test. Post-mortem examinations were conducted on some of the eastern rosellas, and selected tissues from 24 birds positive for BFDV were examined using routine histological methods for the presence of characteristic inclusion bodies.
RESULTS: Of the eastern rosellas, 24/162 (14.8%) were positive for BFDV, and the 95% confidence interval (CI) for true prevalence was estimated as 8.6–20.4%, which varied between regions. Eastern rosellas that were positive for BFDV showed no clinical or histological signs of disease or inclusion bodies. Of the sulphur-crested cockatoos, 70/255 (28%) were positive for BFDV, and the 95% CI for true prevalence was calculated as 22–33%.
CONCLUSIONS: The surprisingly high prevalence of BFDV in wild eastern rosellas and sulphur-crested cockatoos has serious implications for the conservation of native parrots and the export of wild-trapped parrots and cockatoos from New Zealand. Serological studies for BFDV in wild exotic parrots, and molecular studies of virus genotype, are recommended to further characterise the origin and epidemiology of the disease in populations of wild exotic parrots and cockatoos in New Zealand.
Acknowledgements
This study was supported financially by the Department of Conservation (DOC), Environment Bay of Plenty, the Ecology Department and the Institute of Veterinary, Animal and Biomedical Sciences (Massey University), and the Wildlife Society of the New Zealand Veterinary Association. The sampling efforts by the DOC, the Ornithological Society of New Zealand, Nga Manu Nature Reserve, Auckland Zoo Centre for Conservation Medicine, Wellington Zoo Trust, Environment Bay of Plenty, and Aotearoa Wildlife are acknowledged. Also, we would like to thank staff at the EpiCentre and the Equine Parentage and Animal Genetic Services Centre (Massey University) for their technical support.
Notes
1G Knopfers, Aotearoa Wildlife, Te Puke, New Zealand