Total Solar Eclipses Can Trigger Dawn Behavior in Birds, Scientists Say

On April 8, 2024, a total solar eclipse disrupted the light-dark cycles of North American birds in anticipation of spring breeding. By collecting more than 10,000 community observations and artificial intelligence analysis of nearly 100,000 vocalizations, ornithologists at Indiana University found that those few minutes of unexpected daylight darkness significantly affected bird behavior; More than half of the wild bird species changed their biological rhythms, and many of them gave a morning chorus after the eclipse.

The daily and seasonal rhythms of birds are tightly regulated by changes in light and darkness.

But what happens when these cycles are suddenly interrupted, such as during a total solar eclipse?

While past studies have attempted to understand the effects of solar eclipses on animal behavior, most have offered only scattered or anecdotal insights into how animals respond.

Indiana University researcher Liz Aguilar and her colleagues viewed the April 2024 total eclipse as a rare research opportunity, providing an unprecedented natural experiment to study how birds respond to sudden changes in light.

In anticipation of an eclipse that would bring nearly 4 minutes of daytime darkness across much of the central and eastern United States, they created SunnyBirda smartphone app that allowed users to record bird behavior during the eclipse in real time.

Its use by citizen scientists has produced nearly 10,000 observations covering the 5,000 km path of the eclipse.

At the same time, the researchers deployed autonomous recording devices at sites throughout southern Indiana, which recorded nearly 100,000 bird calls before, during and after the all-out period.

These records were analyzed using BirdNETan artificial intelligence system capable of identifying species and quantifying vocal activity.

Of the 52 species detected, 29 showed significant changes in their vocal behavior at some point during the event, but the eclipse did not affect all species equally, according to the findings.

In the minutes before the complete collapse, 11 species sang more than usual and the sky darkened.

During four minutes of darkness, 12 species responded: some went silent, while others became more active.

The strongest reaction occurred after the return of the Sun, when 19 species changed their songs, resembling the chorus of a false dawn.

Barred owls called four times more often than usual, and robins, known for their pre-dawn songs, sang six times more often than usual.

“These patterns suggest that the eclipse temporarily resets some birds' biological clocks, prompting them to behave as if a new day had just begun,” the scientists said.

Their paper published in the October 9, 2025 issue of the magazine. Science.

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Liz A. Aguilar etc.. 2025. Total solar eclipse induces dawn behavior in birds: Evidence from acoustic recordings and social science. Science 390 (6769): 152-155; doi: 10.1126/science.adx3025