Seroprevalence of psittacine beak and feather disease in wild psittacine birds in New South Wales

Abstract

A haemagglutination inhibition assay was used to detect antibody to psittacine beak and feather disease virus in sera from wild sulphur crested cockatoos (Cacatua galerita), galahs (Eolophus roseicapillus), short-billed corellas (Cacatua sanguinea), eastern long-billed corellas (Cacatua tenuirostris) and other psittacine birds in New South Wales. The seroprevalence of psittacine beak and feather disease ranged from 41% to 94% in different flocks, indicating infection with the virus is widespread in wild populations.

Evidence of Psittacine Beak and Feather Disease Virus Spillover Into Wild Critically Endangered Orange-Bellied Parrots (Neophema Chrysogaster)

“…Nevertheless, the three wild birds we investigated represent more than 6% of the wild population of this species. In endemically infected flocks high antibody prevalence balanced by low disease prevalence reflects self-sustaining cycles of infection and immunologic stimulation, which supports the development and maintenance of flock immunity (Raidal et al, 1993). The absence of detectable antibody in the blood of wild Orangebellied Parrots also supports the absence of endemic BFDV in this species.…”

“…The threshold susceptible population size required to maintain BFDV endemically in psittacine populations is unknown but, with less than 50 individuals, the wild population of Orange-bellied Parrots is almost certainly too small to maintain one, let alone two, BFDV genotypes on its own (Raidal et al, 1993(Raidal et al, , 1998Swinton et al, 1998). Nevertheless, the three wild birds we investigated represent more than 6% of the wild population of this species.…”

“…The possibility that identical or closely related BFDV lineages are found in other parrots in Australia but simply remain so far undetected is far more likely. The disease is common throughout all of Australia (Ashby, 1907;Raidal et al, 1993) and there is evidence for it occurring in wild Budgerigars (Melopsittacus undulatus) in 1936 when an outbreak was described near Blackall, Queensland. Many more isolates of circovirus from wild Australian parrots need to be analyzed to provide a more complete understanding on the phylogenies currently being examined.…”

“…At least four of these-the Sulphurcrested Cockatoo (Cacatua galerita), Little Corella (Cacatua sanguine), Galah (Eolophus roseicapillus), and Rainbow Lorikeet (Trichoglossus haematodus)-have expanded their range and population, and are known to occupy hollows used by other psittacine species. Cacatua galerita, the Sulphur-crested Cockatoo, was the first species in which PBFD was described and is known to maintain a high prevalence of antibody to BFDV in wild populations (Raidal et al, 1993). The role of natural and artificial nest hollows in the transmission of BFDV and other viruses (Raidal et al, 1998;Mackie et al, 2003) in wild Australian psittacine birds needs to be much better characterized.…”

“…Very little data exist implicating BFDV or other infectious disease in the decline of other Australian psittacine birds, despite suggestions that disease should be considered as a factor in the extinction of the Paradise Parrot (Psephotus pulcherrimus) (Garnett, 1992). Nevertheless, PBFD has been long recognized in Australian wild birds (Powell, 1903;Perry, 1981;Raidal et al, 1993), with the first record of an epidemic with PBFD-like syndrome occurring in Red-rumped Parrots (Psephotus haematonotus) from 1887 to 1888 in the Adelaide Hills, South Australia, which was blamed for the almost complete extirpation of the species from that area for more than 20 yr (Ashby, 1907). In New Zealand, Mauritius and South Africa PBFD is recognized as a threat to many threatened psittacine bird species (Heath et al, 2004;Ortiz-Catedral et al, 2009).…”