There's something disconcerting about darkness in the middle of the day.
You get a taste of that feeling when a storm suddenly rolls in overhead, but a total solar eclipse, like the one a 70-mile-wide swath cutting across the US will see on August 21, is a far more shocking moment.
Dusk will suddenly begin as the moon temporarily moves in between Earth and the sun. For those in the zone of totality, where the sun will be fully blacked out, a night-like darkness will fall. The world will become cool.
Even the animals will take note. Some report that they start acting like it's night, running around in wild ways, or that they stop to observe the event — though much of this is based on anecdotal reports, not well-documented studies. No one knows exactly what most of them will do, but at least some reaction is expected.
"It has been reported during many eclipses that many different animals are startled by totality and change their behavior thinking that twilight has arrived," according to NASA.
There are only studies on a few different kinds of animals. At least one type of orb-weaving spider has been seen to begin disassembling its webs at the start of the totality, as if it were the end of the day, according to one study. Orb weavers typically destroy their webs and rebuild new ones each morning — they started rebuilding when the sun came back out.
Chimpanzees in a research center at least seemed fascinated and gathered together to seemingly gaze in the direction of the sun during an eclipse, according to another study.
Some people have reported that animals like cows will return to their barns, though that behavior has not always appeared when studied.
Birds have been observed to suddenly go silent as the moment of totality arrives, according to a story published in Audubon.
"Most songbirds will treat it as nightfall, as long as they’re in the 100 percent in the eclipse pathway," ecology professor Scott McWilliams told Audubon. "Diurnal songbirds will become quiet; nocturnal birds the opposite. Thus, for the most part, silence will follow the darkness."
Owls are likely to be active, and bats might take to the sky as well, according to the Nashville Zoo.
The zoo and a number of other organizations encourage people who want to observe animals and report their behavior to do so on an app created by the California Academy of Sciences called iNaturalist.
Some anecdotal reports are even more fascinating. Observers have said that giraffes and llamas begin to run around, appearing to be confused by whats happening and stopping when it ends.
Even more intriguing is what animals in the ocean may or may not do. Some scientists have said they've seen dolphins and whales rising to the surface in groups at the beginning of a total solar eclipse. "The smarter animals freak out," Douglas Duncan, director of the University of Colorado's Fiske Planetarium, told Time.
As for the sharks? Do creatures that have been around for more than 400 million years take note when the sun suddenly disappear? As shark scientist David Shiffman recently noted on Twitter, we don't really know.
—Dr. David Shiffman (@WhySharksMatter) August 16, 2017
