Avian Malaria

Science Center Objects

Avian malaria is a mosquito-borne disease of birds caused by a protozoan parasite (Plasmodium relictum). P. relictum reproduces in avian red blood cells. If the parasite load is sufficiently high, the bird loses red blood cells (anemia). Because red blood cells are critical for moving oxygen about the body, loss of these cells can lead to progressive weakness and, eventually, death.  This disease was introduced to Hawaii and native honeycreepers are highly susceptible.  Avian malaria has contributed to population declines and extinction of Hawaiian forest birds.  USGS scientists are investigating population impacts and how the dynamics of this disease change with elevation and climate change.

Hawaiian forest bird populations have been negatively affected by the non-native avian malaria parasite. In 2015, the USGS was a partner in the development of models to (1) understand avian malaria dynamics in different species and at different elevations and (2) forecast avian malaria risk in light of climate change. Malaria infections are highest at low elevations and over 90 percent of infected scarlet Hawaiian honeycreepers (I’iwi) die from this disease. 

 

CURRENT RESEARCH

New Technologies and Groundwork for Mosquito Control in the Alakai Plateau

We will investigate methodologies to provide short-term control of vector mosquitoes to support the recovery of endangered, endemic passerines on the island of Kaua‘i.

 

Disease Ecology In the Pacific Basin: Wildlife and Public Health Concerns

Both wildlife and human health in Hawai‘i and other island ecosystems in the Pacific Basin face continued threats from introductions of diseases and vectors. Accidental introduction of mosquito-borne avian malaria and pox virus to Hawai‘i is an outstanding example of how biological invasions can have a profound effect on endemic wildlife. 

 

Avian Pathogens and Vectors - Kahuku Unit of Hawaii Volcanoes National Park

While the Hawaiian avian disease system has been well-studied in the forests of the older section of Hawai‘i Volcanoes National Park (HAVO), and in many other locations throughout the state, nothing was known about avian disease in the new Kahuku Unit of Hawai‘i Volcanoes National Park and the adjacent Kau Forest Reserve. 

 

Environmental DNA (eDNA): a New Tool for Monitoring Status and Trends of Ecosystems and Taxa in Hawaii and Pacific Islands

There is a need to supplement existing monitoring protocols with more cost effective methods that can monitor both individual taxa and entire communities of organisms of interest across larger geographic areas. Recent advances in methodologies for detecting environmental DNA (eDNA) from water and soil are promising and may have applications in Hawaii for monitoring native communities, rare taxa, and high impact invasive species.

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