The Epizootiology and Ecological Significance of Malaria in Hawaiian Land Birds

作者：Charles van Riper, Sandra Guest Van Riper, M. Lee Goff, Marshall Laird · 发表于：Ecological Monographs · 年份：1986 · DOI：10.2307/1942550 · 被引用次数：1203 · 研究领域：Bird parasitology and diseases、Avian ecology and behavior、Animal Behavior and Reproduction

Laboratory and field experiments were conducted on the island of Hawaii from 1977—1980 in an effort to determine the impact of avian malaria on the forest birds. At 16 study sites from sea level to tree line in mesic and xeric habitat, birds were captured and bled to determine the host and altitudinal distribution of blood parasites. In the laboratory, six bird species were challenged with malarial parasites to measure host susceptibility. Distributions, activity cycles, and transmission potentials of malarial parasite vectors were also analyzed. One species of Plasmodium was present from sea level to tree line, concentrated in the mid—elevational ranges in the ecotonal area where vectors and native birds had the greatest overlap. Native forest birds were: (a) more susceptible to malaria than were introduced species; (b) most likely to have malaria during the nonbreeding, wet season; (c) found ranging lower in xeric than in mesic forests; and (d) found to have a lower prevalence of malaria in xeric forests. Temporal as well as elevational differences in prevalence and parasitemia levels of wild birds were apparent throughout the annual cycle, a result of differing host and parasite responses to biotic and abiotic factors. Avian malaria probably did not reach epizootic proportions on Hawaii until after ≈1920. However, since that time it has had a negative impact on the population dynamics of the native forest birds and is today a major limiting factor, restricting both abundan...