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Bethany Jackson BVSc (Hons)

A PhD Thesis

Health and disease in Red-crowned Parakeets (Cyanoramphus novaezelandiae) on Tiritiri Matangi Island; causes of feather loss and implications for conservation managers

This thesis is available in Murdoch University's Digital Thesis collection at: http://researchrepository.murdoch.edu.au/26687/

Supervisors

  • Dr Kris Warren
  • Dr Ian Robertson
  • Dr Carly Holyoake
  • Dr Richard Jakob-Hoff

Research

In 2008, during a translocation event of kakariki (Cyanoramphus novaezelandiae), Beak and Feather Disease Virus (BFDV) was detected for the first time in a wild native New Zealand psittacine. Kakariki on the island sanctuary of Tiritiri Matangi have been experiencing noticeable feathering problems since 2004, although BFDV has not been detected to date. With its proximity to mainland populations of infected eastern rosellas (Platycercus eximius), and the presence of BFDV on nearby islands, it is highly likely kakariki on Tiritiri Matangi have been exposed to this virus. The implications of BFDV are significant for native New Zealand psittaciformes. New Zealand hosts many endemic and unique parrot species, including the critically endangered orange fronted parakeet (Cyanoramphus malherbi) and kakapo (Strigops habroptilus). Most species exist only in fragmented small populations on offshore islands, with translocations a necessary part of their conservation management. They are subject to issues of inbreeding and low genetic diversity, which may render them highly susceptible to novel diseases. There is scant information as to how BFDV interacts with native psittaciformes, particularly the individual and population effects. Determining the risk this disease poses relies on such information.

There are also other pathogens or parasites likely to be present in kakariki of New Zealand, including avian malaria (Plasmodium sp), and feather mites. To understand the role and interactions of these diseases/pathogens, a longitudinal study of health and disease parameters in kakariki is necessary. Tiritiri Matangi is a high priority conservation site with a readily accessible population of kakariki, making it an ideal place to conduct an epidemiological study of health and disease in this species. Information gathered through this research will help guide current and future management of this disease, as well as build a solid baseline dataset of health and disease parameters in kakariki. This project is supported and endorsed by the Department of Conservation (NZ), as part of a joint response to the BFDV emergence with the Ministry of Agriculture and Forestry (MAF).

Research objectives:

  • Serial cross sectional studies with seasonal to determine the presence and prevalence of BFDV in red-fronted parakeets on Tiritiri Matangi, as well as other non-target pathogens such as avian malaria (Plasmodium sp.) and feather mites. Baseline health data will be generated from this work, including haematology, selected biochemistry, faecal parasitology, cloacal and choanal smears, and full physical exam. Screening for BFDV will include blood, feather and faeces, with full genome sequencing of any virus detected.
  • Nest box survey during two consecutive breeding seasons to evaluate breeding success of any affected individuals, including PCR screening of nesting material for virus.
  • Determine prevalence of BFDV in nearby mainland Eastern rosella populations, including full genome sequencing of any virus detected.
  • Determine prevalence of BFDV in domestic/pet kakariki populations, including full genome sequencing of any virus detected. If affected kakariki are found within the domestic population, they will be followed as a case series to provide valuable individual bird data.

Collaboration:

In collaboration with Dr Arvind Varsani of the University of Canterbury, phylogenetic analysis will be conducted to infer relationships between virus isolated in kakariki and Eastern rosella populations. This is critical to our understanding of BFDV in New Zealand, given the likelihood this virus originated in introduced exotic parrots brought to New Zealand for the pet trade.

Support:

This project is funded by the Auckland Zoo Conservation Fund, Murdoch University Research and Development Division, Murdoch University Faculty of Veterinary and Biomedical Sciences, and the New Zealand Centre for Conservation Medicine (NZCCM) of the Auckland Zoo. Sponsors and supporters include the Department of Conservation, the Supporters of Tiritiri Matangi, 360 Degrees Ferry Service, and Bivouac Outdoor Gear Suppliers. Landcare Research New Zealand have provided support through access to expertise and facilities for molecular diagnostics.

Photos provided by Bethany Jackson.

New Zealand Centre for Conservation Medicinebivouac / outdoor - Committed to AdventureTiritiri Matangi Open Sanctuary360 Discovery Cruises