Avian malaria in a remnant population of red-fronted parakeets on Little Barrier Island, New Zealand

Abstract

Avian malaria is recognised as a potential threatening factor for endangered New Zealand birds; nevertheless, analyses of its prevalence are few and often retrospective, following outbreaks in managed species. We conducted an opportunistic polymerase chain reaction (PCR)-based survey for Plasmodium on a remnant population of red-fronted parakeet (Cyanoramphus novaezelandiae) on Little Barrier Island alongside an analysis of haematology profiles as a first assessment of the effects of this parasite on parakeets. We sampled 22 parakeets and detected Plasmodium relictum DNA in nine samples (prevalence 40.9%; 95% CI = 20.49–61.51%). One successfully amplified sequence corresponded to P. relictum haplotype GRW4. Lymphocyte and heterophil to lymphocyte counts did not differ between PCR-positive and PCR-negative parakeets. However, it is unclear which state of the infection cycle the parakeets experienced during our sampling scheme. From a management perspective, our results indicate that translocation of parakeets from Little Barrier Island to sites where introduced reservoirs of P. relictum occur is a sound management option given the current exposure to this microorganism at the source site.