Changing climate and the altitudinal range of avian malaria in the Hawaiian Islands - an ongoing conservation crisis on the island of Kaua'i
Changing climate and the altitudinal range of avian malaria in the Hawaiian Islands - an ongoing conservation crisis on the island of Kaua'i
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DOI：
10.1111/gcb.12535
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发表时间：
2014-08-01
影响因子：
11.6
通讯作者：
Giambelluca, Thomas W.
中科院分区：
文献类型：
--
作者：
Atkinson, Carter T.;Utzurrum, Ruth B.;Giambelluca, Thomas W.
在夏威夷群岛，禽疟的传播在不同的海拔梯度上有所不同，在海拔1500米以下的地区传播最严重，那里的温度和湿度都有利于致倦库蚊（Culex quinquasciatus）唯一的媒介蚊子和疟原虫（Plasmodium relictum）的外部孢子发育。十多年来，人们已经认识到全球变暖对这一系统的潜在影响，人们担心平均温度的升高可能导致疟疾扩展到目前低温限制向高度易感的地方性森林鸟类传播的栖息地。最近，考阿伊岛上两种濒危物种——“Akikiki”（Oreomystis bairdi）和“Akeke’e”（Loxops caerulerostris）的数量下降，以及更常见的本地蜜雀撤退到阿拉卡伊高原最后仅存的高海拔栖息地，这表明，疾病传播方面的预测变化可能正在发生。我们比较了1994-1997年和2007-2013年在青藏高原三个地点采样的森林鸟类疟疾感染率，并评估了同一时间段内可用水生生境中蚊子幼虫的发生变化。高原下部（1100 m, 10.3% ~ 28.2%）、中部（1250 m, 8.4% ~ 12.2%）和上端（1350 m, 2.0% ~ 19.3%）感染率显著增加。在与河流边缘相关的水生生境中，库蚊幼虫的检测同时增加，表明该媒介的种群也在增加。这些增加至少部分是由于当地传播，因为Kaua'i 'Elepaio（一种定居的本地物种）的总体流行率已从17.2%增加到27.0%。在过去的20年里，平均气温上升，降水减少，以及河流流量的变化，在阿拉卡高原的大部分地区创造了支持禽疟疾传播增加的环境条件。
Transmission of avian malaria in the Hawaiian Islands varies across altitudinal gradients and is greatest at elevations below 1500 m where both temperature and moisture are favorable for the sole mosquito vector, Culex quinquefasciatus, and extrinsic sporogonic development of the parasite, Plasmodium relictum. Potential consequences of global warming on this system have been recognized for over a decade with concerns that increases in mean temperatures could lead to expansion of malaria into habitats where cool temperatures currently limit transmission to highly susceptible endemic forest birds. Recent declines in two endangered species on the island of Kaua'i, the 'Akikiki (Oreomystis bairdi) and 'Akeke'e (Loxops caeruleirostris), and retreat of more common native honeycreepers to the last remaining high elevation habitat on the Alaka'i Plateau suggest that predicted changes in disease transmission may be occurring. We compared prevalence of malarial infections in forest birds that were sampled at three locations on the Plateau during 1994-1997 and again during 2007-2013, and also evaluated changes in the occurrence of mosquito larvae in available aquatic habitats during the same time periods. Prevalence of infection increased significantly at the lower (1100 m, 10.3% to 28.2%), middle (1250 m, 8.4% to 12.2%), and upper ends of the Plateau (1350 m, 2.0% to 19.3%). A concurrent increase in detections of Culex larvae in aquatic habitats associated with stream margins indicates that populations of the vector are also increasing. These increases are at least in part due to local transmission because overall prevalence in Kaua'i 'Elepaio (Chasiempis sclateri), a sedentary native species, has increased from 17.2% to 27.0%. Increasing mean air temperatures, declining precipitation, and changes in streamflow that have taken place over the past 20 years are creating environmental conditions throughout major portions of the Alaka'i Plateau that support increased transmission of avian malaria.