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University of Hawai'i |
(808) 956-8856 Telephone |
For Immediate Release: |
September 28, 2000 |
Contact: David Duffy, professor of botany and unit leader, Pacific Cooperative
Studies Unit, University of Hawai'i at Manoa, 956-8814,
dduffy@hawaii.edu
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| UH receives $4.1 million for research on malaria in native birds |
University of Hawai'i at Manoa researcher David Duffy - working with scientists from the U.S. Geological Survey, the Smithsonian and Princeton University - has been awarded a five-year $4.1 million dollar research grant from the National Science Foundation to study malaria in Hawai'i's native birds. Out of 300 applicants, the project was one of 15 awarded in a special competition held by NSF.
Duffy, who heads the Pacific Cooperative Studies Unit in the Department of Botany, leads this project, which will use complexity or chaos theory as a tool to develop new approaches to the problem of avian malaria. The disease has already contributed to the extinction of at least 10 species in Hawai'i and poses a threat to another 22. The project brings together researchers in three fields of investigation: emerging diseases, conservation biology and invasive alien species. Project results may help prevent the extinction of Hawaiian birds and also offer more insight into such problems as West Nile Fever, a disease spread from birds to people by mosquitoes.
Unlike previous approaches to human and avian malaria, the project will analyze how a number of factors interact in the spreading of this destructive disease. Most research on avian malaria has been reductionist - breaking the problem into small parts, studying them intensely and then identifying the key links in the disease cycle. The method has not been successful for human malaria, which remains a major health problem. Similarly, avian malaria resists reduction because of its apparent complexity.
In Hawai'i, while an altitudinal limit to malaria has been recognized - it is too cold for mosquitoes or malaria above a certain elevation - small pockets of endemic birds exist at lower elevations where they should have been exterminated by disease.
"In addition, the mosquito and malaria zone has moved upward in recent years," Duffy says. "Traditional scientific approaches have not been able to explain or predict these events; however, the theory and application of biological complexity may help."
This project will examine how the interplay of human activities, the biology of the mosquito and the disease interact with the ecology and evolution of endemic birds that survived in Hawai'i before humans and their pests arrived. When Europeans came to the islands, they brought mosquitoes, large pigs and birds that probably carried disease. The pigs escaped into the forest, where their rooting and destruction of tree ferns created small pools favored by mosquitoes. These mosquitoes transmitted diseases such as avian malaria and avian pox from imported birds to native ones. Native bird species died out, but malaria continued, maintained in exotic bird species such as bulbuls and mynahs.
At a certain elevation, it became too cold for malaria to survive in cold-blooded mosquitoes. The endemic land birds survived primarily in higher-elevation refuges. More recently, the range of mosquitoes and malaria has extended to higher elevations, and native land birds have disappeared from areas where they were once abundant.
"If the current warming trend continues, there may not be any malaria-free areas except at the highest, tree-less elevations hostile to most Hawaiian native land birds, so that more such species will soon become extinct," Duffy says.
By looking at how many aspects considered together demonstrate emergent properties, Duffy hopes the research will produce insights not available from studies conducted at smaller scales or narrower scopes.
"If the research can explain the conditions under which some native
birds exist in the apparent face of avian malaria, it may suggest conservation
strategies to extend these conditions, perhaps allowing Hawai'i's native
birds to survive into the future," Duffy says.
