Warming mismatch

The seasonal clock that guides migratory songbirds across North America is being disrupted by climate change, leaving some species unable to reach their summer homes by the key dates necessary for breeding success.

Global warming is prompting some plants and insects that the birds rely on to appear earlier or later than in the past, according to a new report published in the journal Scientific Reports.

“We’re seeing springlike conditions well before birds arrive,” said Stephen Mayor of the University of Florida. “The growing mismatch means fewer birds are likely to survive, reproduce and return the following year.”