Early spring (or some of these days that still feel like late winter) can be a confusing time for watching birds migrating back to Maine. Some days it seems like the flood gates are open, as blackbirds and raptors move north, then a cold snap sets them back. Especially in your backyards, the activity around feeders can take wild swings day by day, so I wanted to use this space to explain who is on the move, why we see these ebbs and flows, and what is to come.
First, let’s talk about the birds we think of as residents, like blue jays. Kay, from Sumner, wrote in after noticing a sudden disappearance in backyard jays, going from daily feeder visitors to completely gone for at least several days. Of course a single location change like this could be for a variety of reasons, like a predator moving into the area or new food sources becoming available nearby, but it is important to acknowledge that those blue jays might be getting ready to migrate. We don’t typically think of blue jays as migrating away from Maine in the summer, since they can be seen year-round in the state, but those individuals you see in your backyards and local parks in the winter may be different from the ones that are there in the summer.
While most passerines (perching birds) migrate at night, blue jays are primarily diurnal migrants (active in the daytime), and you can often catch them in the act. We often see small groups of blue jays actively migrating in the mornings during the “Warbler Walks” I lead at Evergreen Cemetery each May. You can typically tell migrating jays by: their altitude, above the treetops up to 500 feet (think of the Washington Monument for scale); their northward orientation, hopefully; and group size, as they’ll be in groups of 5-10 or larger, rather than singly or in pairs.
The timing of a blue jay’s migration is more fluid and reactionary to localized phenomena like weather events or food availability. This puts them in a category with most of the other migrants hitting Maine right now, which is called facultative migrants, and includes birds like red-winged blackbirds, Canada geese and sandhill cranes (an uncommon but increasing nesting species in Maine). During the warm spell we had in early March, there was a big push of these facultative migrants that took advantage of the weather to race north and attempt to claim their breeding grounds early. You are likely to have higher breeding success if you have the best nesting grounds (abundant resources and especially food), and you have a better chance of claiming those areas if you are the first one there.
One interesting example of this was the handful of tree swallows that were reported north of Boston and even in Gorham, on March 10, a very early arrival! As soon as it got cold again, the reports of swallows completely stopped and they weren’t reported again until more than a week later. Tree swallows are aerial insectivores and their food is going to be hard (maybe even impossible) to find in the cold, so they need to make those types of course corrections that a facultative migrant has the liberty to do.
Then we have the obligate migrants, which are those that are “hard-wired” to know when to leave their wintering grounds and do so reliably at the same time each year. These birds generally winter farther south than facultative migrants, so it stands to reason that they wouldn’t know what the weather is like thousands of miles away and can’t risk chancing it, in the same way the aforementioned tree swallows did. This group includes many of the warblers, tanagers, vireos, and flycatchers that will be returning to Maine for the summer, after wintering in Central America, the northern part of South America and the West Indies.
Speaking of which, I’m writing this article from Jamaica, where the warblers are thick! Maine Audubon offers annual international (and domestic) trips to see birds (plus the people, culture, and food), and we picked Jamaica for its density of endemic species (found only here) and wintering populations of “our” birds. Of course “our” birds spend the least amount of the year with us, but it has been fun to encounter American redstarts and northern parulas as some of the most abundant species here.
Most interesting to me is seeing them having completed (or nearly completed) their “prealternate” molt; that is, getting into their breeding plumage. These birds molted into their duller colors last fall before migrating to their wintering grounds, and are now changing into their brightest attire before they migrate back and attempt to catch the eye of a mate.
I’m handing out tiny maps with directions to Maine to all the warblers, and we’ll be seeing them arriving in a few weeks. Mark your calendars for our Warbler Walks at Evergreen Cemetery in Portland, running May 4–8 and May 11–15 at 7 a.m, where we’ll be welcoming these (and nearly 100 total species) back each morning. Or get signed up early for our southern Florida trip in late April 2027, where we’ll catch them en route!
Have you got a nature or wildlife question? It doesn’t have to be about birds! Email questions to [email protected] and visit www.maineaudubon.org to learn more about birding, native plants, and programs and events focusing on Maine wildlife and habitat. Maine Audubon Staff Naturalist Doug Hitchcox and other naturalists lead free bird walks on Thursday mornings starting at 8 am, at Maine Audubon’s Gilsland Farm Audubon Sanctuary in Falmouth.