New research has shown that extreme temperatures can significantly harm the breeding success of birds in farmland habitats.

A team of University of California researchers found that the impact of high temperatures on bird fertility can vary depending on the type of environment in which the species in question breeds – and the birds nesting near agricultural land is half as likely to successfully reproduce a young. Leave the nest when the temperature rises.

On the other hand, forests appear to provide a protective buffer against high temperatures, providing shaded areas that increase nesting success.

Tree swallows are one of the farmland breeding species found to be negatively affected by heat waves (Alexander Viduetsky).

The findings, published in the journal Science , shed light on how climate change may combine with habitat loss to affect bird breeding across the United States.

When researchers looked at how heat waves affected nesting potential in urban areas, they found fewer negative impacts than in agriculture, possibly because nests are often in city parks and residential areas may be covered by tall trees.

The team of researchers analyzed more than 152,000 nest records of nearly 60 bird species that nest in farms, forests, grasslands, and developed areas across the United States over a 23-year period (1998-2020). ).

The researchers also studied which species are most vulnerable to agricultural heat waves. Negative impacts were widely felt for all bird species studied, including the Western Bluebird and Tree Swallow, two species common on farms, which both experienced significant declines in their ability to nest successfully when temperatures soar in agricultural areas.