As the climate warms, spring comes early and birds raise fewer young 

Rising global temperatures are making it harder for birds to know when it’s spring and time to breed. 

In a recent study published in Proceedings of the National Academy of Sciences, researchers found that birds produce fewer young if they start breeding too early or late in the season. With climate change resulting in earlier springlike weather, birds have been unable to keep pace. 

Researchers say the mismatch between the start of spring and birds’ readiness to reproduce is likely to worsen, with consequences that could be catastrophic for many bird populations.  

“By the end of the 21st century, spring is likely to arrive about 25 days earlier, with birds breeding only about 6.75 days earlier,” said the study’s first author, Casey Youngflesh, who led the research as a postdoctoral researcher at UCLA and is now a postdoctoral fellow at Michigan State. “Our results suggest that breeding productivity may decrease about 12% for the average songbird species.” 

Read more from UCLA.