Snow on the Appalachian Trail at the summit of Saddleback Mountain didn’t deter skiers and hikers from taking in the view during the total solar eclipse on April 8. But the timing of the event – so early in the season before most species arrived in Maine – made it nearly impossible to see the impact on bird populations. Robert F. Bukaty/Associated Press

Between the solar eclipse in April and aurora in May, this has been an exciting spring for getting people outdoors and looking up to the skies. There was a lot of hype leading up to the eclipse and a lot of excitement about the aurora, so let’s dig in to both and talk about the effects of these, if any, on wildlife.

Let’s start with the eclipse: Overall, it went pretty much as expected, though a bit less exciting than we had hoped. The eclipse itself was obviously incredible, but the timing may have lessened some of the reactions we were expecting to see from Maine’s wildlife. Because it was in early April, many of our nesting birds hadn’t returned to the state yet, so breeding behavior was limited – specifically the lack of bird songs. One commonly documented behavior during solar eclipses is that birds are fooled into thinking it is morning when the sun reemerges, and temporarily begin their dawn chorus.

I hiked up to Borestone Mountain, in Elliotsville, for the eclipse and only heard one pine siskin briefly sing during the eclipse. Otherwise it was very quiet. Around the state, we did get reports from people noticing birds singing, even outside of the path of totality. I was also hoping to hear a frog chorus as it got dark, but in early April there was still ice and a couple of feet of snow over the ponds at Borestone.

The other common behavior reported during the eclipse was birds going to roost. This was most commonly reported in large birds like turkey vultures, since they want warm thermals rising off the Earth’s surface to glide on, and also perhaps because they are large and easier to detect than most small songbirds.
This behavior is also seen in chimney swifts during solar eclipses, but that species was still a month away from reaching Maine during this particular event.

That gets us to the recent aurora. The magnetic storm that produced the vibrant colors of the aurora was reported as the strongest to hit Earth since October 2003. Scientists have long theorized that birds use the Earth’s magnetic field to aid in migration, but it has only been more recently that studies have shown some birds possess a protein in their retina that is sensitive to magnetic fields. In birds that migrate, these proteins are more magnetically sensitive than in non-migratory species. So it may not be much of a surprise that the Earth being bombarded during a magnetic storm would have some effect on our birds. Even back in 1977 when this connection was unknown, Frank Moore of Clemson University wrote about migrants like robins and warblers possibly being affected.

Fast forward to last fall, when a paper in “Proceedings of the National Academy of Science” by Ben Winger, et al, reported that during space weather events, they documented a “9 to 17 percent reduction in migration.” We do see large swings on any given night based on other factors, especially weather, but this research finally shows what effects are coming from beyond our atmosphere.

Another study, published earlier in 2023, found a link between vagrancy in birds and solar activity. These off-course vagrants, birds occurring outside of their known range, are known to occur from a few catalysts, like being blown by storms or just flying too far during their migration, but this is an exciting new finding.

An important context for all of this is that we are currently approaching the peak of our current solar cycle. During this time, known as the solar maximum, we see increased solar activity, like sunspots (which you can look for, if you kept your eclipse glasses) and solar flares (resulting in auroras). NOAA’s Space Weather Prediction Center currently estimates that this cycle’s maximum will occur between late 2024 and early 2026, so time will tell what effects these storms will have on wildlife. Hopefully we get more opportunities to observe and study them. Let me know if you noticed anything else during these events, and keep your questions coming.

Have you got a nature question of your own? Email questions to ask@maineaudubon.org and visit maineaudubon.org to learn more about birding, native plants, and programs and events focusing on Maine wildlife and habitat. Doug and other naturalists lead free bird walks on Thursday mornings, 7 to 9 am, at the Gilsland Farm Audubon Sanctuary in Falmouth.