Critically endangered populations of animals are at an increased risk of stochastic extinction following reductions in population size due to disease. Psittacine Beak and Feather Disease (PBFD) has been identified as a key threatening process for the critically endangered Orange-bellied Parrot (Neophema chrysogaster) in Australia for this reason.
Following more than a decade of intensive surveillance for the disease, PBFD has emerged in both captive and wild Orange-bellied Parrots in recent years and appears to be causing mortalities of offspring in the tiny remnant wild population of fewer than 50 birds. The origin of this emergent pathogen in this species remains unknown, but its potential affect on recruitment is of particular concern.
We have generated a significant database of whole-genome beak and feather disease virus (BFDV) genotypes, which is beginning to shed light on the geographical and host distribution of this virus in Australia. Nevertheless sampling bias amongst wild parrots has left considerable gaps, and may explain our inability to determine the origin of the BFDV spillover into wild Orange-bellied Parrots. Future management of this virus in critically endangered parrots such as the Western Ground Parrot (Pezoporus flaviventris) and Swift Parrot (Lathamus discolor) will most likely rely on the development of an effective vaccine. Our work elucidating the structure of the capsid protein of BFDV has implications for both vaccine development and our understanding of the virulence of this highly mutable and genetically diverse virus.