文章来源:未知 文章作者:enread 发布时间:2023-10-30 08:59 字体: [ ]  进入论坛

Millions of Baby Birds Are Dying from Extreme Heat

CLIMATEWIRE | Millions of young birds die from extreme heat in farm fields across America in what researchers say is a growing threat from climate change that could affect avian populations.
The nestlings and chicks often perish from dehydration1 and the affects of thermoregulation, especially when they fledge in "open cup" nests and bird boxes located in unshaded fields, according to researchers at the University of California, Davis.
Their survival also depends on the ability of mating adults to forage2 for food and support the nest, both of which can be impeded3 by extreme temperatures.
“We know that habitat conversion4 [for agriculture] is already affecting biodiversity and species health on farms,” Katherine Lauck, co-lead author of the paper and a Ph.D. candidate in ecology at UC Davis, said in an interview.
“When you combine that with extreme heat associated with climate change, it’s creating some unique conditions that birds did not evolve with,” Lauck added. "Fundamentally, this is about whether nestlings survive or not.
The findings, published Thursday in the journal Science, add to a growing body of research about the effects of climate change on birds that scientists say are indicators5 of ecological6 decline. In 2019, experts from seven major ornithological7 institutions and nonprofits estimated that North America’s breeding adult birds had declined by 30 percent since 1970, a loss of nearly 3 billion birds.
While the declines were caused by a variety of factors — including habitat loss, predation, food scarcity8 and building collisions — nestlings are increasingly jeopardized9 by climate change, the UC Davis researchers found.
They determined10 that in unshaded farm fields — where temperatures can be 10 degrees Celsius11 higher than in nearby forests — mating adults have “significantly diminish[ed] reproductive success” compared to those living in forest areas. Scientists define reproduction success as having at least one fledgling emerge from a nest per breeding season.
While heat stress affects birds across all habitat types, the researchers found that “common generalist” species like western bluebirds and tree swallows were particularly vulnerable to heat in rural America, with “significant declines in nesting success when temperatures spiked12 in agricultural areas.”
They also found that birds living in unshaded open-cup nests and bird boxes were more vulnerable to heat waves than those nesting in tree holes and more shaded areas. The trends were observed across every farming region of the country.
“This suggests that species already in decline may have an even greater difficulty rearing young in the future as heat waves become more common and more land is converted to agriculture,” Daniel Karp, an associate professor of biology at UC Davis who led the data collection effort, said in a statement.
The findings are based on an analysis of 152,000 nesting records collected by NestWatch, a program by the Cornell Laboratory of Ornithology13 in which local volunteers monitor nests and report signs of bird health and behavior using an online app. Data includes things like the number of eggs laid, adult nesting behaviors and the activities of baby birds.
The approach allowed researchers to assess 58 bird species in habitats such as farms, forests, grasslands14 and developed areas. The data spanned a 23-year period beginning in 1998.
Conor Taff, a research associate at the Cornell lab, said the UC Davis study is notable for its nationwide scale and provides a large data source for researchers who have traditionally focused on distinct regions. He also said the paper provides a foundation upon which scientists can study more species and the effects climate change is having on their habitats.
Reprinted from E&E News with permission from POLITICO, LLC. Copyright 2023. E&E News provides essential news for energy and environment professionals.


1 dehydration UYkzX     
  • He died from severe dehydration.他死于严重脱水。
  • The eyes are often retracted from dehydration.眼睛常因脱水而凹陷。
2 forage QgyzP     
  • They were forced to forage for clothing and fuel.他们不得不去寻找衣服和燃料。
  • Now the nutritive value of the forage is reduced.此时牧草的营养价值也下降了。
3 impeded 7dc9974da5523140b369df3407a86996     
阻碍,妨碍,阻止( impede的过去式和过去分词 )
  • Work on the building was impeded by severe weather. 楼房的施工因天气恶劣而停了下来。
  • He was impeded in his work. 他的工作受阻。
4 conversion UZPyI     
  • He underwent quite a conversion.他彻底变了。
  • Waste conversion is a part of the production process.废物处理是生产过程的一个组成部分。
5 indicators f46872fc1b5f08e9d32bd107be1df829     
(仪器上显示温度、压力、耗油量等的)指针( indicator的名词复数 ); 指示物; (车辆上的)转弯指示灯; 指示信号
  • The economic indicators are better than expected. 经济指标比预期的好。
  • It is still difficult to develop indicators for many concepts used in social science. 为社会科学领域的许多概念确立一个指标仍然很难。
6 ecological IrRxX     
  • The region has been declared an ecological disaster zone.这个地区已经宣布为生态灾难区。
  • Each animal has its ecological niche.每种动物都有自己的生态位.
7 ornithological 05fff1359f2d1b1409fd1725f6f8e5c7     
  • Is there an ornithological reason for keeping them in separate cages? 用独立的笼子养鸟,有什么鸟类学的原因吗? 来自电影对白
  • Mere amateurs in 2009 will make ornithological history in China by discovering birds unknown to science. 在即将来临的2009年里,中国鸟类学史大概会由不打眼的业余人士通过发现未知的鸟类而刷新。 来自互联网
8 scarcity jZVxq     
  • The scarcity of skilled workers is worrying the government.熟练工人的缺乏困扰着政府。
  • The scarcity of fruit was caused by the drought.水果供不应求是由于干旱造成的。
9 jeopardized accbc5f810050021e69367411f107008     
危及,损害( jeopardize的过去式和过去分词 )
  • The soldier jeopardized his life to save his comrade. 这个士兵冒生命的危险救他的同志。
  • The occasional failed project or neglected opportunity does not jeopardized overall progress. 偶然失败的项目或失误的机会并没有影响总的进展。
10 determined duszmP     
  • I have determined on going to Tibet after graduation.我已决定毕业后去西藏。
  • He determined to view the rooms behind the office.他决定查看一下办公室后面的房间。
11 Celsius AXRzl     
  • The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
  • The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。
12 spiked 5fab019f3e0b17ceef04e9d1198b8619     
  • The editor spiked the story. 编辑删去了这篇报道。 来自《简明英汉词典》
  • They wondered whether their drinks had been spiked. 他们有些疑惑自己的饮料里是否被偷偷搀了烈性酒。 来自辞典例句
13 ornithology HJCxh     
  • He found his vocation in ornithology.他发现自己适于专攻鸟类学。
  • His main interests are botany and ornithology.他主要对植物学和鸟类学感兴趣。
14 grasslands 72179cad53224d2f605476ff67a1d94c     
n.草原,牧场( grassland的名词复数 )
  • Songs were heard ringing loud and clear over the grasslands. 草原上扬起清亮激越的歌声。 来自《现代汉英综合大词典》
  • Grasslands have been broken and planted to wheat. 草原已经开垦出来,种上了小麦。 来自《简明英汉词典》