The best of EcoWatch, right in your inbox. Sign up for our email newsletter!
Researchers from the University of Michigan and the Field Museum in Chicago studied 70,716 dead birds from 52 different species, including sparrows, thrushes and warblers, that were collected between 1978 and 2016, according to CNN. They found that 49 species got smaller by a statistically significant degree.
"We found almost all of the species were getting smaller," lead author and assistant professor at the University of Michigan's School for Environment and Sustainability Brian Weeks told BBC News. "The species were pretty diverse, but responding in a similar way. The consistency was shocking."
Weeks found that the birds' lower leg bone shrank by 2.4 percent. At the same time, their wingspans increased by a mean of 1.3 percent. The scientists think that warmer temperatures reduced the birds' size, and wingspans increased to compensate, since smaller bodies mean less energy to power the birds through their long seasonal migrations.
"Migration is an incredibly taxing thing they do," Weeks told BBC News.
Animal species tend to be smaller in the warmer parts of their range, a phenomenon known as Bergmann's Rule, according to a University of Michigan press release. But while scientists have theorized animals could shrink as their habitats warmed due to climate change, there hasn't been clear evidence that it is in fact happening.
The University of Michigan researchers were able to find some because they had access to a unique dataset: Since 1978, Field Museum Collections Manager Emeritus Dave Willard has collected and catalogued more than 100,000 birds that died on the streets of Chicago after colliding with its skyscrapers. Willard told CNN he began collecting the birds when someone mentioned they were hitting the windows of the McCormick Place convention center, just a mile from the museum.
"Why let them go to waste when they could be specimens in a museum?" he told CNN.
Because of the efforts of Willard and a team of volunteers, researchers had access to a treasure trove of bird specimens during a period when their breeding grounds north of Chicago warmed by around one degree Celsius. The data didn't just show that the birds' bodies changed as temperatures warmed overall, it also showed them alter in response to shorter-term temperature changes.
"Periods of rapid warming are followed really closely by periods of decline in body size, and vice versa," Weeks said in the press release. "Being able to show that kind of detail in a morphological study is unique to our paper, as far as I know, and it's entirely due to the quality of the dataset that David Willard generated."
- Climate Change Is Making Animals Smaller - EcoWatch ›
- Climate Change Leading to Fatal Bird Conflicts - EcoWatch ›
EcoWatch Daily Newsletter
By Charli Shield
At unsettling times like the coronavirus outbreak, it might feel like things are very much out of your control. Most routines have been thrown into disarray and the future, as far as the experts tell us, is far from certain.
By Elizabeth Henderson
Farmworkers, farmers and their organizations around the country have been singing the same tune for years on the urgent need for immigration reform. That harmony turns to discord as soon as you get down to details on how to get it done, what to include and what compromises you are willing to make. Case in point: the Farm Workforce Modernization Act (H.R. 5038), which passed in the House of Representatives on Dec. 11, 2019, by a vote of 260-165. The Senate received the bill the next day and referred it to the Committee on the Judiciary, where it remains. Two hundred and fifty agriculture and labor groups signed on to the United Farm Workers' (UFW) call for support for H.R. 5038. UFW President Arturo Rodriguez rejoiced:
By Julia Conley
A council representing more than 800,000 doctors across the U.S. signed a letter Friday imploring President Donald Trump to reverse his call for businesses to reopen by April 12, warning that the president's flouting of the guidance of public health experts could jeopardize the health of millions of Americans and throw hospitals into even more chaos as they fight the coronavirus pandemic.
By Melissa Kravitz Hoeffner
Over six gallons of water are required to produce one gallon of wine. "Irrigation, sprays, and frost protection all [used in winemaking] require a lot of water," explained winemaker and sommelier Keith Wallace, who's also a professor and the founder of the Wine School of Philadelphia, the largest independent wine school in the U.S. And water waste is just the start of the climate-ruining inefficiencies commonplace in the wine industry. Sustainably speaking, climate change could be problematic for your favorite glass of wine.