The total solar eclipse on April 8, 2024 comes at an exciting time for wild birds. Local birds sing for mates and fight for territories as they prepare for their once-a-year chance to breed.
Tens of millions of migratory birds will pass through the totality route, migrating mostly at night.
Because birds use light to adapt their behavior to their environment, scientists like us have many questions about how they will respond to eclipses. Will they stop fighting and courting and turn to bedtime-like behavior? How about a nocturnal animal or nocturnal migrant like an owl? Will they start rustling from their perches before they realize it’s not night?
As behavioral biologists at Indiana University, we study wild breeding birds to understand why animals behave the way they do in response to environmental challenges and opportunities. For the 2024 eclipse, our team is starting a new project and developing an application. If all goes as planned, we will have a large dataset collected by community scientist volunteers across the country following the eclipse.
There’s an app for that
On average, a total solar eclipse in the same location occurs only once every 375 years. Like most humans, most wild animals have never seen the sky quickly turn into night in the middle of the day. These rare events are a natural experiment that can help scientists like us understand how animals respond to unusually sudden changes in light.
Most past research on animal behavior during total solar eclipses is anecdotal. Observers reported that zoo animals were acting distressed or entering confined spaces. Scientists have found that spiders begin to tear apart their webs day and night, and farmers have heard their roosters begin to crow after the integration, as if it was dawn once again. Other reports suggest more subtle effects on animal behavior.
Large amounts of standardized data can help make sense of these observations. But because the totality covers such a large area of the Earth in a short period of time, it would be impossible for one scientist or even a small team to obtain enough observations to understand why some animals respond more strongly to solar eclipses than others.
With collaborators across our campus (including Jo Anne Tracey from the Office of Science Outreach and Paul Macklin from Indiana University’s Luddy School of Informatics, Computing, and Engineering) we created an app called SolarBird.
Anyone can download SolarBird for free from the Apple Store and Google Play. The app asks participants to find a bird and watch or listen to it for 30 seconds while clicking through several prompts on what the bird is doing before, during and after totality. You don’t need any prior knowledge or bird expertise to participate.
These types of public science projects have helped make many scientific discoveries, and we hope the public can also help us learn more about the behavior of birds during eclipses. Anyone can help. Even observations outside the totality collect important baseline data.
Technology and bird behavior
Apps like Solarbird aren’t the only technology that helps researchers observe more than any single scientist can see or hear.
For example, during the solar eclipse in August 2017, researchers collected data from weather stations across the United States, including several locations along the path of totality. Like the weather forecaster on your local news channel, they used radar to detect movement in the sky, but focused on the radar signatures of flying insects and birds instead of clouds.
The team saw some changes in activity; Essentially the birds did not follow typical daytime activity patterns as much, but did see a consistent increase in night-like activity. Because they use radar, it’s not clear exactly which bird behaviors are increasing or decreasing.
The eclipse in April 2024 will last longer than the one in 2017, with four minutes of darkness. And with the arrival of spring, the birds sing like a storm.
Bird songs generally convey two critical messages: “stay away” to a rival and “come hither” to a prospective mate. It’s also really easy for those watching the singing to spot it. Most birds sing at 85 decibels measured from 1 meter away. This is the equivalent of a lawn mower; It’s loud enough that even in your garden or a public park you’ll notice it’s happening or stop suddenly.
Along with Dustin Reichard of Ohio Wesleyan University, our team deployed passive sound recorders to record how the eclipse affected bird singing.
Researchers tracking wildlife have been using autonomous recording units for years. These army green, weatherproof devices are about the size of a tissue box and are usually attached to a tree, recording almost anything within earshot. There are currently 20 of them in rural, suburban and urban areas.
Advances in software are helping to automate the process of identifying bird songs by species with less work on the human side. We started recording in the last week of March to collect song ratios at a typical dawn and a typical dusk. We also measured important controls, such as how many birds were normally singing at 3:06 p.m., the peak of totality in Bloomington, Indiana.
We hope to use these recordings to understand why some animals may be more or less affected by solar eclipses.
For example, artificial light at night can affect bird physiology, behavior and abundance, and a total solar eclipse gives us a new way to test how light pollution affects behavior.
City birds may have become accustomed to strange changes in light. Forest dwellers may differ from meadow birds depending on the amount of light in their natural habitat. Or social species may increase alarm calls; This could provide insight into how animals use social bonds to navigate the unknown.
If you are on the path to wholeness this April, be sure to attend the celestial spectacle. But you might also want to look around and listen to the birds, insects, and other wildlife to see how they’re reacting to this once-in-a-lifetime moment.
This article is republished from The Conversation, an independent, nonprofit news organization providing facts and authoritative analysis to help you understand our complex world. Written by: Kimberly Rosvall, Indiana University and Liz Aguilar, Indiana University
Read more:
Kimberly Rosvall receives funding from the National Science Foundation.
Liz Aguilar receives funding from the National Science Foundation and the Indiana Space Grant Consortium.