There have been a number of anecdotes told about animal behavior during a total eclipse of the sun, but not much scientific evidence. In the 1500’s there were reports of birds falling from the sky. Since then there have been numerous other reports about birds becoming silent or perching and chickens returning to their roost, etc. Because total solar eclipses happen so rarely, there is little information on the phenomenon as to how it affects animals. Because eclipses are so rare, it is unlikely that organisms have developed any consistent or predictable response to them.
For this recent eclipse, Monday, August 21, 2017, the California Academy of Sciences’ free iNaturalist app is spinning out a special feature called Life Responds that lets users log wildlife sightings 30 minutes before, 5 minutes during, and 30 minutes after the eclipse. They can add notes and photos for every organism that’s spotted or heard. It isn’t necessary to identify every species; the iNaturalist community can jump in later and help with that.
So what exactly should contributors look for? “Focus on the change,” “Did vocalizations stop? Did a new species appear or disappear? Did movements change? Did a flower fold its petals or a bird return to the nest? According to the Cal Academy “We are hoping to use the power and numbers of citizen science to collect as much data and as many observations as possible.”
The California Academy of Sciences also has a few tips on how to collect the best intel. First, try to find an observation point away from human disturbance. Locate the species you’d like to study before the eclipse. Once it begins, do your best to remain quiet and still so you can document wildlife behavior without influencing it. And be sure to record notes even if nothing seems to happen—this in itself is a valuable piece of information.
I went out for a long bird walk during, in my area of northern California, a partial (80%) eclipse, and watched the birds. I didn’t see anything unusual. Northern Mockingbirds were being territorial, displaying and singing, Great Blue Herons flew overhead, and California Towhees scratched for seeds. I don’t think birds react to an eclipse any differently than they would when a big black storm cloud covers the sun. Eclipses are just too rare and brief to have any meaningful impact on wild animals. But they are cool.