Poster Presentation 64th International Conference of the Wildlife Disease Association 2015

Investigating avian malaria transmission dynamics: the New Zealand situation (#114)

Chris Niebuhr 1 , Robert Poulin 1 , Dan Tompkins 2
  1. Zoology, University of Otago, Dunedin, New Zealand
  2. Landcare Research, Dunedin, New Zealand
Avian malaria, caused by protozoan blood parasites of the genus Plasmodium, is a concern for native New Zealand birds; this mosquito-borne disease has impacted both captive populations and wild individuals in the country.  However, whether or not it is a cause of concern to native, wild populations is still unclear.  In Hawai’i, avian malaria has been a major factor in the population declines of native forest bird species and limits the elevational distribution of many remaining species.  At our study site (Nelson Lakes National Park, South Island, New Zealand), declines in native forest bird abundance have been reported over the past 30 years.  Avian malaria is one possible cause of these declines, since they generally occurred at lower altitudes where more potential reservoir birds and mosquito vectors may be present.  In addition to the invasive mosquito vector Culex quinquefasciatus, also found in Hawai’i, New Zealand’s native C. pervigilans is also suspected of playing a role in malaria transmission, complicating our understanding of local transmission dynamics. 
Blood samples were taken from native and non-native forest birds along an elevational gradient (650m to 1400m) during three summers (2012-13 to 2014-15), complimented with mosquito sampling.  Here we will present our findings to date, describing the avian malaria community detected (including data on host prevalence, vector surveys, and Plasmodium spp. sequencing results).  We will also discuss our work in adapting a malaria-forest bird epidemiological model (originally developed in Hawai’i) to fit the New Zealand situation, incorporating both C. quinquefasciatus and C. pervigilans. This work has potential for informing on management beyond avian malaria as well, as other mosquito-borne diseases (e.g. West Nile, Ross River, and dengue) could eventually make their way into New Zealand.