Surprising ways animals react to solar eclipses
Giraffes, spiders, and even whales have been seen changing their behavior during a total solar eclipse.
Solar eclipses occur twice a year, when the moon passes between the sun and Earth, which casts a shadow across some areas.
There are several types of solar eclipses. An annular solar eclipse occurs when the moon is at its farthest point from Earth, so it appears smaller than the sun. When the moon blocks part of the sun, it creates a partial solar eclipse and the sun appears as a crescent.
Sometimes, the moon’s path causes a total solar eclipse. When that happens, the sky darkens to twilight levels and air temperatures drop within the “path of totality.” In that case, the moon completely blocks the sun, which appears as a ring around the moon. It can also produce a dazzling “diamond ring” effect before and after totality.
Whether they’re total or annular, solar eclipses are awe-inspiring phenomena that can provoke some extreme psychological responses in many people. According to biologists and longtime eclipse chasers, humans aren’t the only ones reacting to the dramatic changes in the sky.
People who have witnessed these effects have also noted that a variety of animals seem to change their behaviors in response to total solar eclipses.
What happens during a solar eclipse
Reports of unusual animal reactions to solar eclipses date back centuries. One of the earliest stories comes from Ristoro d’Arezzo, an Italian believed to be a monk, who described what happened during a total eclipse on June 3, 1239.
National Geographic History Magazine
As the sun disappeared and the sky turned dark, “all the animals and birds were terrified; and the wild beasts could easily be caught,” he wrote.
(Amazing sights you can only spot while viewing a solar eclipse)
During an eclipse seen in Portugal on August 21, 1560, astronomer Christoph Clavius wrote that during totality, “stars appeared in the sky and (marvellous to behold) the birds fell down from the sky to the ground in terror of such horrid darkness.”
While it’s hard to confirm such colorful anecdotes from history, modern astronomers and eclipse chasers have also reported wild and domestic animals noticeably reacting to eclipses. Dairy cows return to the barn, crickets begin chirping, birds either go to roost or become more active, and whales breach in the seas.
Veteran eclipse-chaser Peter den Hartog traveled to Hungary in 1999 to experience totality, and he remembers seeing various species of birds and bats suddenly appear during totality.
“[Was it because of] the light intensity, or the flies and mosquitoes that came out … I’m not sure, but I‘ve definitely experienced more activity during eclipses,” Hartog says.
Eclipse-chaser and author Dave Balch was in Kona, Hawaii, for the 1991 total eclipse and noticed excited activity among the birds along the pier during the partial phases before and after totality.
“We could hardly hear each other talk! Then came totality—not a sound. It was deathly quiet. The difference between the noise levels before and during totality was stunning.”
Eclipse-chaser Tora Greve was on an expedition to Zambia in 2001 when she noticed that, just as the sun disappeared, frogs began making sounds and raptors stopped circling, possibly due to the change in thermals as the air cooled.
Around the water hole where she was standing, she says, giraffes “started running about during the whole totality. When the sun came back, they stopped and began grazing the trees again.”
(See 100 years of eclipse-chasing captured in quirky pictures.)
How scientists study animals during a solar eclipse
Collecting scientifically meaningful data on animal reactions to total solar eclipses is tough business. The paths of eclipses are scattered around the world, and many are visible only from remote regions. That makes it hard to obtain anything more than a few data points per event.
“If you really want to study behavior in a comprehensive way, you have to spend a lot of time in the field observing and have rigorous protocols in place,” says ecologist Rebecca Johnson at the California Academy of Sciences.
“If you are an animal behavior ecologist setting up to just study effects of solar eclipses, it can be near impossible.”
To improve the scientific record, Johnson helped create the Life Responds project, which runs on a dedicated smartphone app called iNaturalist. Her team of biologists and astronomers used the app to collect data from the millions of people who witnessed the total eclipse that occurred on August 21, 2017 and on April 8, 2024.
“We created this project that very simply asks people wherever they are—whether they are under totality or partial eclipse—to spend some time outside looking at animals and observing their behavior before, during, and after the eclipse,” Johnson told National Geographic in 2017.
In 2024, NASA launched its own citizen science project, Eclipse Soundscapes, which is focused on learning how crickets respond to the eclipse. Anyone can participate by recording data, analyzing audio, or submitting their own observations.
(How do animals respond to eclipses? Help NASA find out.)
The best way to observe animals during a solar eclipse
People who want to help by reporting observations through these citizen science opportunities should scout out in advance where they will be watching the eclipse and think about which animals will be around them. For instance, if you happen to be in a suburban backyard or city park, you may be best able to report on urban invertebrates such as ants and spiders. It’s important to note that you should always wear eclipse glasses when viewing the sky during a solar eclipse.
(Here’s how to view a solar eclipse safely.)
Anecdotal evidence suggests that orb-weaving spiders destroy their webs during an eclipse, so Johnson recommends finding a web to watch.
“That might be something particularly easy for people to observe,” she says, “because [spiders] don’t move very far like flying birds, and so there is a higher likelihood of recording slower invertebrate behavior.”
The hope is to create a meaningful clearinghouse for animal behavior during eclipses that scientists can use to advance their research.
(Do bats take flight during a solar eclipse? Here’s what we learned.)
“The collection of observations and looking for patterns is where science begins, and we hope to bring scientists to the data to spur their research moving forward,” Johnson said in 2017.
“Hopefully we’ll end up documenting something [during solar eclipses] that no one has ever seen before.”
