The 2024 total solar eclipse that swept across North America did more than dazzle observers; it offered a rare natural experiment for scientists studying how light shapes animal behavior. A new study shows that 29 species of birds altered their vocalizations before, during, and after the eclipse, and many answered the sun’s return with a remarkable, dawn-like chorus that never truly existed in nature that day.
H2: A crowdsourced approach to a celestial event
In Bloomington, Indiana, educators and researchers at Indiana University (IU) seized the moment to engage the public in science. Their mission was to explore how dramatic shifts in light influence wild birds, and they built SolarBird, a free smartphone app designed to crowdsource frontline observations from across North America. As IU Ph.D. student Liz Aguilar explained, the app helps scientists extend their reach while inviting people to observe closely and listen carefully, turning spectators into citizen scientists.
Users of SolarBird were asked to observe a bird (or birds) in their location for 30 seconds before totality, during totality, and after totality, recording behaviors such as singing, alarm calls, and changes in flight. In addition to crowdsourced data, researchers placed automated recorders around Bloomington to capture a more comprehensive picture of vocal activity. The combined approach yielded a rich dataset: more than 1,700 participants submitted roughly 11,000 observations, complemented by almost 100,000 bird vocalizations analyzed with BirdNET, the neural-network backbone behind many modern bird-identification tools.
H2: What the data revealed about bird behavior
Across the study, 29 of 52 monitored species showed some change in vocalization in response to the eclipse, but there was no uniform pattern. For some species that attempted to sing during totality, the unusual lighting appeared to disrupt typical rhythms. Others stayed quiet or shifted to different call types. The most striking finding came after totality—the moment when sunlight slowly returned and the sky brightened again.
H3: The “false dawn chorus” phenomenon
As daylight returned, a majority of the responding species engaged in what scientists are calling a “false dawn chorus.” Twenty-nine species produced dawn-like vocalizations that resembled birdsong typically heard at sunrise. This is not a true morning chorus; rather, it appears that birds, finely attuned to cues such as light intensity and spectral composition, interpreted the sudden return of light as if a new day had begun.
H2: Why light cycles matter to birds—and what this means for urban life
The Eclipse study underscores how sensitive bird physiology and behavior are to changes in light. Birds rely on reliable cues from the sun to regulate daily cycles, including feeding, mating, and territorial defense. The eclipse disrupted these cues in ways that were visible to human observers and audible to researchers through the BirdNET-assisted recordings.
The authors suggest that artificial lighting and urban environments, which can distort natural light cycles, might have analogous effects on birds in cities. If a brief solar dimming can shift singing patterns, sustained or misaligned lighting could influence daily schedules, energy expenditure, and communication networks among urban bird populations.
H2: Public science in action and future directions
Kimberly Rosvall, an IU professor who advised Aguilar, notes the broader implications of the finding beyond the eclipse event. The study shows that citizen science, when paired with automated monitoring and advanced analytics, can capture subtle episodes of animal behavior that might otherwise be missed. This has important ramifications for urban ecology, conservation planning, and understanding how animals communicate under rapidly changing light environments.
As researchers continue to parse the data, they hope to extend the SolarBird framework to other events and habitats. The eclipse offered a rare, temporary interruption in the regular light cycle, but ongoing urbanization and artificial light at night will continue to challenge birds’ circadian rhythms—and our ability to study them in real time.
H2: A note on curiosity and collaboration
The 2024 eclipse reminded scientists and the public that nature responds to celestial events in unexpected ways. By turning a dramatic moment into a learning opportunity, the SolarBird project bridged astronomy, ornithology, and citizen science, inviting people to listen closely to the dawn chorus—whether real or false.
