Disoriented Animals Behave Strangely During Total Solar Eclipses

From spiders that dismantle their own webs to bats taking flight mid-afternoon, a solar eclipse can prompt a plethora of bizarre animal behavior.

By Cody Cottier
Mar 19, 2024 6:00 PM
Elephants during a total solar eclipse
(Credit: 1001slide/Getty Images)


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On April 8, 2024, when the moon passes between the Earth and sun, the resulting solar eclipse will darken skies to a dim twilight for 5 minutes across a wide swath of North America. Most necks will be craned toward the celestial spectacle, but if you look around you may witness something just as captivating: a bunch of baffled creatures trying to make sense of the unexpected gloom.

For many of them, life revolves around solar patterns. As the daily cycles of light and dark change with the seasons, they look upward for their cues on when to wake, when to eat, when to sleep, when to reproduce. But when their guiding light is suddenly extinguished, as during a solar eclipse, they become disoriented.

“Puzzled animals that are active during the day head back to their nighttime abodes,” writes animal behavior researcher Steve Portugal in an article in The Conversation, “while nocturnal animals think they’ve overslept.” And since any given spot on Earth only sees an eclipse every few hundred years, each one is a first and last for those who live through it.

Eclipses Through the Ages

For centuries, anecdotal accounts have pointed to a connection between these cosmic phenomena and bizarre animal behavior. One of the first comes from an Italian monk named Restoro d'Arezzo, who observed an eclipse in 1239.

“All the animals and the birds became frightened," d'Arezzo wrote, "and the wild beasts could be captured with ease.”

Of course, there’s no telling how prone these early commentators were to embellishment.

Read More: Here's Your Guide to Seeing the 2024 Solar Eclipse

An Army of Celestial Observers

Even for dedicated biologists, it’s hard to collect much data on something as brief and infrequent as a total solar eclipse, which occurs only once every couple years and lasts a few minutes at most. In modern times, however, researchers have done their best.

One of the first in-depth studies published by Coolidge and several colleagues in the Proceedings of the American Academy of Arts and Sciences dates to 1932. Before an eclipse in Maine that August, the Boston Society of Natural History solicited reports from every conceivable source: newspapers, game wardens, trained naturalists and the public at large.

They wound up with nearly 500 observations, which revealed a stunning range of abnormal behavior. Crickets “set up a lively chirping just as they do at nightfall,” while mosquitoes “appeared and pestered us terribly.” Gulls began “to repair to their night roosting grounds,” and sheep “came into their evening pens, bleating.”

Read More: Large and In Charge, Hippos Are Stirring Up Trouble In Colombia

Intriguingly, in places where the eclipse was just shy of complete (about 98 percent or less), animals typically didn’t react at all. But in the path of totality, something was clearly out of the ordinary.

Weird Animal Behaviors During an Eclipse

Over the decades since, scientists have documented all sorts of peculiar goings-on during eclipses. In May 1984, in Atlanta, they saw captive chimpanzees gather at the top of a climbing structure, turning their bodies and faces toward the surprising scene above. In July 1991, in Mexico, they watched as orb-weaving spiders dismantled their webs, only to rebuild them as soon as the sun returned.

The situation is just as perplexing for nocturnal species. During that same eclipse in 1991, researchers stationed outside a cave in Mexico saw several species of bats emerge from their roosts in the middle of the afternoon, seemingly tricked by the artificial dusk.

That said, many studies have also turned up inconclusive or negative results. Collectively, the data suggest that behavioral responses “may be complex, confusing, and often contradictory,” as a team of biologists put it in a 2020 paper. (Their own results showed a discernible response — either anxiety or premature nighttime routines — in 75 percent of species at the Riverbanks Zoo in South Carolina.)

Citizen Scientists Can Help Survey Animals During an Eclipse

The so-called Great American Eclipse of August 2017, visible across the entire country, revived curiosity about how these natural wonders impact animals. Leveraging public enthusiasm (215 million people viewed the eclipse, either in person or online), the California Academy of Sciences launched “Life Responds,” a citizen science project hosted on the iNaturalist app.

In a reboot of the 1932 effort in Boston, some 600 people submitted nearly 3,000 observations, making Life Responds the largest repository of eclipse behavior data to date (not to mention the most geographically widespread by far, with ears and eyes from coast to coast).

Read More: How Long Will The Solar Eclipse Last? It Depends

The project’s findings mirrored those of previous efforts — many inconclusive or negative reports, but also plenty of fascinating trends. Swallows and swifts became more active, whereas ants slowed their pace or momentarily stopped; frogs croaked up a chorus while certain flowers closed their petals; dogs and cats, for whatever reason, seemed pretty unphased.

Many questions remain, however, and with modern tools it’s easier than ever to address them. After the 2017 eclipse, biologists at the University of Nebraska found that social media from that single occasion produced more observations than all previous academic literature combined. “This outlet can capture a wider spectrum of species and behaviors,” they write, ”highlighting topics of further exploration.”

This year there’s yet another attempt to replicate the 1932 study: NASA’s Eclipse Soundscapes Project. The plan is for participants to submit not only written observations but also sound recordings, offering a multisensory perspective on how the eclipse influences various U.S. ecosystems.

What's more, the Life Responds project is once again seeking data collectors for next month’s eclipse, says Rebecca Johnson of the California Academy of Sciences. Anyone viewing it can participate, even if their location isn’t in the path of totality. More information is available here.

Humans Act Odd During Eclipses, Too

These animals may seem comically misguided, but we shouldn’t be too quick to judge. Our own species, with all its brainy might, didn’t discover the cause of eclipses until well into the modern era. Early humans considered them supernatural events and, generally, bad omens. Some experts think the Inca even fell back on human sacrifice to appease the obviously enraged sun god.

Read More: 20 Of The Best Places To View The 2024 Total Solar Eclipse

In other words, they were in the same confused boat as the animals; when night intruded upon day, no one knew what to make of it. You could even argue the animals handled it better — many just hit the hay early, no need for ritual slaughter.

In fact, when it comes to odd eclipse-induced behavior, we may even top the list. In its 1932 report, the Boston Society noted that during one recent eclipse a woman was seen “on her knees praying aloud and seizing handfuls of earth which she put in her mouth.” The animal kingdom, in contrast, “has shown no demonstration of extreme nervous or mental disturbance such as that recorded of Homo sapiens.”

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