{"title":"Weather and regional effects on winter counts of Rusty Blackbirds (Euphagus carolinus)","authors":"Chris J. Kellner, Weijia Jia, Araks Ohanyan","doi":"10.5751/ace-02694-190205","DOIUrl":null,"url":null,"abstract":"<p>A long-term and severe population decline of Rusty Blackbirds (<em>Euphagus carolinus</em>) has motivated biologists to search for possible causes of the decline. Several hypotheses have been forwarded, one of which is that habitat destruction on the overwintering grounds is responsible. Climate change is another possible explanation. We evaluated the population trend of Rusty Blackbirds in Arkansas by modeling their abundance recorded during Christmas Bird Counts conducted between 1965 and 2020. We used generalized additive modeling to evaluate population trends and explored the influence of weather, effort, habitat, and region on those trends. We found that counts of Rusty Blackbirds have increased by about 40 birds in Arkansas between 1965 and 2020; most of the increase occurred after 1995. We also found that proportion of forest land in each count circle’s county was inversely related to counts of Rusty Blackbirds but that temperature was a more important variable. During warmer years, fewer Rusty Blackbirds were counted. Rusty Blackbird geographic distribution also changed by decade; that change accounted for about 15% of the deviance in counts of Rusty Blackbirds. Finally, we observed a relationship between temperature and distribution; Rusty Blackbirds tended to overwinter in the northern portions of the state during warm years and more southerly portions of the state during cold years. Our analytical approach will be useful to anyone evaluating geographic shifts in populations that might be associated with climate change.</p>\n<p>The post Weather and regional effects on winter counts of Rusty Blackbirds (<em>Euphagus carolinus</em>) first appeared on Avian Conservation and Ecology.</p>","PeriodicalId":49233,"journal":{"name":"Avian Conservation and Ecology","volume":"27 1","pages":""},"PeriodicalIF":1.4000,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Avian Conservation and Ecology","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.5751/ace-02694-190205","RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"BIODIVERSITY CONSERVATION","Score":null,"Total":0}
引用次数: 0
Abstract
A long-term and severe population decline of Rusty Blackbirds (Euphagus carolinus) has motivated biologists to search for possible causes of the decline. Several hypotheses have been forwarded, one of which is that habitat destruction on the overwintering grounds is responsible. Climate change is another possible explanation. We evaluated the population trend of Rusty Blackbirds in Arkansas by modeling their abundance recorded during Christmas Bird Counts conducted between 1965 and 2020. We used generalized additive modeling to evaluate population trends and explored the influence of weather, effort, habitat, and region on those trends. We found that counts of Rusty Blackbirds have increased by about 40 birds in Arkansas between 1965 and 2020; most of the increase occurred after 1995. We also found that proportion of forest land in each count circle’s county was inversely related to counts of Rusty Blackbirds but that temperature was a more important variable. During warmer years, fewer Rusty Blackbirds were counted. Rusty Blackbird geographic distribution also changed by decade; that change accounted for about 15% of the deviance in counts of Rusty Blackbirds. Finally, we observed a relationship between temperature and distribution; Rusty Blackbirds tended to overwinter in the northern portions of the state during warm years and more southerly portions of the state during cold years. Our analytical approach will be useful to anyone evaluating geographic shifts in populations that might be associated with climate change.
The post Weather and regional effects on winter counts of Rusty Blackbirds (Euphagus carolinus) first appeared on Avian Conservation and Ecology.
期刊介绍：
Avian Conservation and Ecology is an open-access, fully electronic scientific journal, sponsored by the Society of Canadian Ornithologists and Birds Canada. We publish papers that are scientifically rigorous and relevant to the bird conservation community in a cost-effective electronic approach that makes them freely available to scientists and the public in real-time. ACE is a fully indexed ISSN journal that welcomes contributions from scientists all over the world.
While the name of the journal implies a publication niche of conservation AND ecology, we think the theme of conservation THROUGH ecology provides a better sense of our purpose. As such, we are particularly interested in contributions that use a scientifically sound and rigorous approach to the achievement of avian conservation as revealed through insights into ecological principles and processes. Papers are expected to fall along a continuum of pure conservation and management at one end to more pure ecology at the other but our emphasis will be on those contributions with direct relevance to conservation objectives.
京公网安备 11010802042870号
京ICP备2023020795号-1
分享
求助内容：
应助结果提醒方式：
扫码关注我们
