A male common house sparrow with two juveniles. Researchers found that body size of some birds decreased significantly as the summer temperatures increased.

Birds Are Losing the Climate Fight

Global warming causes some species to become smaller

By Nadeem Badshah

Global warming is causing some bird species to shrink, a study has suggested.

Researchers in Chicago have found that sparrows and thrushes have become smaller over the past four decades. Their wings, however, have become slightly longer.