北美腹地人們最熟悉的一些鳥類,，包括冠藍(lán)鴉、知更鳥,、藍(lán)知更鳥和鷦鷯,，在過去30年因感染西尼羅河病毒而使種群數(shù)量急劇下降。該病毒在美國第一次見諸報(bào)道的爆發(fā)是在紐約市地區(qū),，發(fā)生在1999年,，可能是由一只感染了該病毒的鳥或蚊子進(jìn)入該地區(qū)造成的。對(duì)繁育鳥群所做的一項(xiàng)新的研究顯示,，該事件造成的損失要比人們曾經(jīng)預(yù)料的大得多——大到足以引起人們對(duì)該事件對(duì)整個(gè)生態(tài)系統(tǒng)穩(wěn)定性的影響表示擔(dān)憂,。這項(xiàng)工作反映了一個(gè)入侵病原體對(duì)本地野生動(dòng)物能夠產(chǎn)生的潛在的毀滅性影響， 也讓我們看到了野生動(dòng)物貿(mào)易的潛在危險(xiǎn),。
英文原文：
Nature 447, 710-713 (7 June 2007) | doi:10.1038/nature05829; Received 8 November 2006; Accepted 11 April 2007; Published online 16 May 2007
West Nile virus emergence and large-scale declines of North American bird populations
Shannon L. LaDeau1, A. Marm Kilpatrick2 & Peter P. Marra1
Smithsonian Migratory Bird Center, National Zoological Park, Washington DC 20008, USA
Consortium for Conservation Medicine, New York, New York 10001, USA
Correspondence to: Shannon L. LaDeau1 Correspondence and requests for materials should be addressed to S.L.L. (Email: [email protected]).
Abstract
Emerging infectious diseases present a formidable challenge to the conservation of native species in the twenty-first century1. Diseases caused by introduced pathogens have had large impacts on species abundances2, including the American chestnut3, Hawaiian bird species4 and many amphibians5. Changes in host population sizes can lead to marked shifts in community composition and ecosystem functioning3, 4, 6. However, identifying the impacts of an introduced disease and distinguishing it from other forces that influence population dynamics (for example, climate7) is challenging and requires abundance data that extend before and after the introduction2, 5. Here we use 26 yr of Breeding Bird Survey (BBS)8 data to determine the impact of West Nile virus (WNV) on 20 potential avian hosts across North America. We demonstrate significant changes in population trajectories for seven species from four families that concur with a priori predictions and the spatio-temporal intensity of pathogen transmission. The American crow population declined by up to 45% since WNV arrival, and only two of the seven species with documented impact recovered to pre-WNV levels by 2005. Our findings demonstrate the potential impacts of an invasive species on a diverse faunal assemblage across broad geographical scales, and underscore the complexity of subsequent community response.
