A Yale University study published on May 28, 2025, in *Nature Ecology & Evolution*, reveals the struggle of North American bird species to adapt to climate change. Led by Jeremy Cohen, the study challenges the assumption that birds can easily relocate to escape rising temperatures.
Researchers analyzed 406 North American bird species over 20 years. They found that while many species tried to shift their ranges northward or to higher elevations, they couldn't keep pace with climate change. In summer, species shifted ranges by 40-50 miles, reducing heat exposure by about 1.3°C. However, the continent warmed faster, leaving birds in territories 1.35°C warmer than their original range.
Winter was more challenging, with movements reducing warming by only 11%. Typical winter temperatures in occupied areas rose by 3.7°C, with relocation shaving off less than half a degree. Some species, like the blue-winged warbler, adapted better by moving over 100 miles north, while others, like the cactus wren, remained due to specialized habitat needs. The study emphasizes conservation efforts to protect habitat corridors and reduce emissions to aid vulnerable bird species.