Psittacine beak and feather disease: ecology and implications for conservation

ABSTRACT

Beak and feather disease virus (BFDV) is the dominant pathogen of wild Psittaciformes in Australasia where it has been present for at least 10 million years. The richness of psittacine avifauna in this region has produced a mixture of potential hosts for the pathogen resulting in competing forces of virus co-evolution, spill-over infection and virus host-switches within parrots, cockatoos and lorikeets. Recent evidence has shown that all threatened and endangered Australian psittacine bird species can be infected by BFDV genotypes from any other close or distantly related host reservoir species; however, lorikeets harbour a sympatrically segregated BFDV genotype. The potential for BFDV to act as a keystone pathogen in the Australian landscape exists since many psittacine beak and feather disease-affected birds succumb to other primary or opportunistic pathogens transmissible more broadly among non-psittacine birds. Conservation efforts for the Orange-bellied Parrot (Neophema chrysogaster), one of the world’s most critically endangered bird species, have been significantly hampered by BFDV infection and much has been learnt in the past two decades about the molecular biology of this important pathogen. While BFDV is recognised as a Key Threatening Process by the Australian government all the available evidence indicates that little has been achieved to mitigate the threat of BFDV to endangered psittacine species, particularly for captive breeding programs.

KEYWORDS:

• Circovirus
• psittacine beak and feather disease
• host generalism
• spill-over infection
• Key Threatening Process

Acknowledgements

We thank Ian Fellows and Peter Poole for permission to use their photographs of PBFD-affected parrots.

Additional information

Funding

This work was supported by the Australian Research Council [DP1095408, LP120100448].