Oskar Mattes of Deer Isle, left, and Nellie Haldane of Blue Hill try to spot a Steller’s sea eagle in Georgetown on Dec. 31. The bird had been spotted near Five Islands pier the day before and was later spotted just a few miles north of the harbor. Brianna Soukup/Staff Photographer
As we started 2022, my inbox was being filled with dozens of questions about one bird: the Steller’s sea eagle that appeared in Georgetown on Dec. 31. Check out Deirdre Fleming’s article for more on that story. I want to answer a few of the most frequent questions I’m getting about this eagle, as I often do when rare birds show up in Maine.
A 2015 photo of a Steller’s sea eagle in Pittsburgh. Gene Puskar/Associated Press
First, why is it here? The reason for vagrancy can vary and answers are often educated guesses, at best. There is definitely an over-tendency for people to say a rare bird was “blown in on a storm” because that rarely happens. We do sometimes see tropical seabirds get caught in the eye of a hurricane that are displaced to wherever the storm makes landfall, but those birds typically are very quick to reorient and fly back to their normal range. A pattern of vagrancy in cave swallows has been established in the northeast when we get a south-southwest wind across the country in the fall.
Readers may remember in January 2021 when two purple gallinules – long-toed birds from tropical wetlands – showed up in Maine, a phenomena well documented to occur during dry spells in their native range. This is an example of dispersal, which we have also seen with birds from out west, presumably responding to wildfires. The list goes on, but a common assumption for many vagrants is that they are prospecting. This is a natural way that species expand their range; in some cases, they may find a new area to establish for breeding, but also possibly a new area to overwinter. Rufous hummingbirds are a good example of a western species that used to winter in Mexico, but has recently established a wintering population in the southeastern United States, and maybe being closer to their breeding grounds gives them an advantage come spring!
Second, is it a boy or a girl? Always a funny question, especially because we so often assign gender to animals that cannot be sexed visually, like this Steller’s sea eagle. One of my favorite experiences with the famous great black hawk of Portland was hearing how people would describe it using different genders based on what it was doing. The quotes ranged from “Wow, look at him tearing apart that squirrel” to “Aw, she looks so cold just perched there.” We do know that a majority of vagrants are male (as the great black hawk was). This can easily be told with sexually dimorphic species, where the males and females look different, but even with monomorphic (where sexes look alike) species, we can sometimes use structural features to tell them apart. Looking at the shape of the outer flight feathers in some flycatchers is always a fun way to sex species like western kingbirds or fork-tailed flycatchers in Maine. There may be some bias here, since males tend to be brighter and therefore more likely to be detected. However, there are plenty of really dull rare birds that are found, too.
Third, will it survive? Probably the toughest question, emotionally, because most vagrants probably don’t make it. In most cases, for birds to be hundreds, if not thousands, of miles out of their normal range, they are likely to be exposed to something – be it weather, food scarcity, outdoor cats or another novel predator – that will be a challenge to its survival. It is helpful to have context around this, like the fact that the majority of birds don’t survive their first year. Larger birds generally have higher survival rates than smaller songbirds, which can be approaching 90% mortality during that tough first year, and it helps that larger birds generally have fewer young and more parental care. Our common black-capped chickadees only have an average lifespan of two to three years. Like the fact above that many vagrants tend to be male, they also tend to be immature, thus vagrancy may just be another factor in the high mortality rate. The Steller’s sea eagle is an interesting outlier in that it is an adult. Like our bald eagles – which take five years to reach their adult plumage, with the classic white head, dark body, white tail – Steller’s sea eagles take four years to get their adult plumage. We cannot sex the Steller’s, but we do know it is at least 4 years old.
Last, who cares? Just kidding – no one actually asked this! But I thought it’d be fun to share that there were a TON of people who cared about the Steller’s sea eagle while it was in Maine. It was hard to keep count, but I estimated 600 people connected with the bird on New Year’s Eve, and from reports, it is conservative to say 1,500 people saw the bird by the end of that first weekend, ending Jan. 2. While I’m sure I missed some, I know we had birders from all New England states, as well as from New York, Pennsylvania, Maryland, New Jersey, Ohio, Arizona, Washington, D.C., Florida, Tennessee, Georgia, New Mexico and California. I do want to say many thanks to the lobstermen who shared the wharf as they took their traps out for the season, and also to Robbie Pinkham for being so helpful in getting people to see the bird. The owners of the Grey Havens Inn graciously allowed hundreds of people to see the eagle from their property and even provided hot coffee on that wet and cold day.
Many thanks to these people and all the rest of the folks in this small quiet Maine village that was overrun by birders over the New Year!
Do you have a nature question for Doug? Email questions to ask@maineaudubon.org and visit www.maineaudubon.org to learn more about backyard birding, native plants, and programs and events focusing on Maine wildlife and habitat. Doug leads free bird walks on Thursday mornings, 8 to 10 a.m., at the Gilsland Farm Audubon Sanctuary in Falmouth.
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