Pathogenicity of avian malaria in experimentally-infected Hawaii Amakihi

Journal of Wildlife Diseases
By: , and 



The introduction of avian malaria (Plasmodium relictum) and mosquitoes (Culex quinquefasciatus) to the Hawaiian Islands (USA) is believed to have played a major role in the decline and extinction of native Hawaiian honeycreepers (Drepanidinae). This introduced disease is thought to be one of the primary factors limiting recovery of honeycreepers at elevations below 1,200 m where native forest habitats are still relatively intact. One of the few remaining species of honeycreepers with a wide elevational distribution is the Hawaii Amakihi (Hernignathus virens). We measured morbidity and mortality in experimentally-infected Hawaii Amakihi that were captured in a high elevation, xeric habitat that is above the current range of the mosquito vector. Mortality among amakihi exposed to a single infective mosquito bite was 65% (13/20). All infected birds had significant declines in food consumption and a corresponding loss in body weight over the 60 day course of the experiment. Gross and microscopic lesions in birds that succumbed to malaria included enlargement and discoloration of the spleen and liver and parasitemias as high as 50% of circulating erythrocytes. Mortality in experimentally-infected amakihi was similar to that observed in Apapane (Himnatione sanguinea) and lower than that observed in Iiwi (Vestiaria coccinea) infected under similar conditions with the same parasite isolate. We conclude that the current elevational and geographic distribution of Hawaiian honeycreepers is determined by relative susceptibility to avian malaria.

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Publication type Article
Publication Subtype Journal Article
Title Pathogenicity of avian malaria in experimentally-infected Hawaii Amakihi
Series title Journal of Wildlife Diseases
DOI 10.7589/0090-3558-36.2.197
Volume 36
Issue 2
Year Published 2000
Language English
Publisher Wildlife Disease Association
Contributing office(s) National Wildlife Health Center
Description 8 p.
First page 197
Last page 204
Country United States
State Hawaii
Online Only (Y/N) N
Additional Online Files (Y/N) N
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