Little Corella parrot with an advanced case of Psittacine Beak and Feather Disease

A type of cockatoo called a little corella (Cacatua sanguinea) infected with beak and feather disease virus, which has spread through the pet trade. Credit: cbstockfoto/Alamy

Conservation biology

Virus that robs parrots of their plumage has spread around the globe

Beak and feather disease virus has appeared in eight countries where it had been unknown.

A virus that can inflict feather loss and severe beak deformities on infected parrots is widespread in the wild.

Infections with beak and feather disease virus, which can cause lethal illness, are common in captive cockatoos, parakeets and other types of parrot. But how far the virus, which originated in Australasia, has spread in wild bird populations has been a mystery.

Deborah Fogell at the University of Kent in Canterbury, UK, and her colleagues screened wild and captive parakeets and parrots from five species. The testing revealed viral DNA in birds from eight countries where the virus had not previously been recorded, including nations home to threatened parrot species.

In some cases, viruses isolated from one bird population were closely related to viruses found in populations of a separate species living thousands of kilometres away, suggesting that the virus had been recently introduced by the pet trade. The team also found the first evidence of infection in wild rose-ringed parakeets (Psittacula krameri) — an invasive species that continues to spread globally — living in their native range.