by A dog wearing sunglasses with safety lenses is seen during the annular eclipse on October 14, 2023. Credit – Anadolu-Getty Images
ohf all the animals are worth watching during a total solar eclipse, some of the most interesting animals are humans. They stop what they are doing; they stare skyward; they lower their voices. Perhaps some of them would gather their young gardens. Some tears may even be shed. If you’ve ever seen a solar eclipse, none of this is surprising; in fact, you have certainly exhibited some of these behaviors as well. Other species of animals show other kinds of behavioral changes, as weather and lighting and nature itself seem to be turning on their axes. So what should you expect to experience on April 8, as a total eclipse crosses the US from the southwestern tip of Texas to the northern tip of New England?
Some of the biggest changes will happen far in front of us, in the ionosphere, the band of atmosphere that goes from an altitude of 60 to 300 km (37 to 190 miles.). Defined by the abundant presence of electrically charged particles or ions, the ionosphere is denser during the day, disturbed by incoming radiation from the sun.
As NASA explains, that means the total concentration of ions in the ionosphere drops during an eclipse. This reduction can cause the upper atmosphere to cool, which can cause local depletion known as “ionospheric holes”. This has an impact on populations on the ground as these cavities can interfere with the transmission of radio signals and lead to anomalies in GPS navigation systems. As researchers at Embry-Riddle University and Clemson University determined after the 2017 total eclipse, however, in most cases the disruption to GPS is transient and too mild for users to notice.
Read more: How Cities Around the US Are Celebrating the Eclipse
Other natural changes are universally observable, notably the steady diminution of sunlight. The entire arc across North America is only 185-km (115 mi.) wide. In this band, a sort of deep dusk descends, with something much more subtle darkening the farther you move from that central point. In 2017, a team from TIME traveled to Casper, Wyo. to record and report on that year’s eclipse from a hillside above the city bowl. Street lights and headlights went on as the sunlight quickly receded.
If you’re out during the fullness, it might pay to have a sweater or jacket. Temperatures can drop anywhere from 2.8°C to 8.4°C (5°F to 15°F) as the sunshine fades, according to the Channel. Falling temperatures near the earth’s surface can cause what is known as “eclipse wind,” or a slowing of the wind. This results in low-level air being cooler than the high-level air above it – known as a temperature inversion – making it harder for that high-level atmosphere to mix with the air closer to it. to the ground, which eliminates the temperature and density. differences that lead to breezes and gusts. As the total comes to an end, the winds come back.
Another possible effect of falling temperatures is the appearance of thunderstorms, as cooler air closer to the ground pushes warmer, more humid air upwards, where the moisture condenses and rain The process is similar to the way sea breezes can create brief storms in the summer.
Read more: The ‘Devil’s Comet’ will be a companion star in Heaven during the Eclipse. Here’s What to Know
All of this affects non-human animals in multiple ways. Night-feeding insects, bats and birds emerge as the sky darkens, sometimes enough to be detectable on radar, the Weather Channel says. Birdsong tends to become quieter as darkness descends, rising again as the light emerges. Crows, seagulls and sparrows have been seen in flight landing on trees or on the ground and pouncing on any chips, calls or berries. Dogs may cower or display other fearful behaviors. Bees may return to their hives and domestic horses and cows may move to their stables, reports Liz Aguilar, a PhD candidate in biology in Indiana University’s evolution, ecology and behavior program. In wild herds or in paddocks far from their barns, horses may also huddle and start shaking their heads and tails – although it is not entirely clear why they engage in these movements. Head shaking and tail flicking is much more common as an agitated response to flies, or to resistance or discomfort from being ridden. A so-called “photographic shake” occurs when horses are exposed to bright sunlight – exactly the opposite of what happens during an eclipse.
In the 2020 paper in the journal Animals, researchers looked at domesticated and zoo animals and recorded a range of eclipse-related behaviors. The cowering and other expressions of anxiety seen in dogs have also been observed in baboons, gorillas, giraffes, and lions, as well as in parrots and other species of lorikeets. Turtles, Komodo dragons, and other types of reptiles, which may already lie largely motionless in the sun, grow even more persistent.
Perhaps the most remarkable thing, however, was the behavior of captive troops of chimpanzees at the Yerkes Primate Research Center on the campus of Emory University in Georgia, during the annular eclipse of May 30, 1984. As researchers reported in the report. American Journal of Primatology, the animals moved to the highest point of a climbing structure in their enclosure and turned their faces upwards towards the sun and moon. One young man went towards the slowly setting sun. The chimps stayed that way until the skies began to lighten, when they descended from the structure. No one can say for sure how they experienced what they were seeing – whether they felt their own kind of curiosity or wonder or even reverence. It is clear, however, that they were all caught up in it. It’s a reaction very similar to what humans feel – one that we may share with untold numbers of other species as the great spectacle of the solar sky unfolds.
Write to Jeffrey Kluger at jeffrey.kluger@time.com.
