Who calls Maine home?
As spring comes to a close and the migration season winds down, we experience a lull in general bird activity. This drop comes from two main factors: many birds have migrated farther north, and those that did stay—including our resident species — are really hard to detect right now. Michael Gelsanliter of Portland wrote in asking exactly about this, with the fun question of “which warblers stay to breed?”
We have around 300 species of birds that regularly occur in Maine, which includes our resident species, the passage migrants (transient visitors), and some of the uncommon species that show up annually that are thought of as vagrants, like dickcissels or yellow-breasted chats. Of those, 231 were documented as breeding in the state during the Maine Bird Atlas (2018-22). Lately, I’ve been writing about the “warbler walks” we hosted in Portland during peak migration in May, and all of the birding festivals around the state since then, but many of those birds we craned our necks for in May and early June are going to be somewhere in Maine all summer.
The blackburnian warbler is one of my favorite examples of these. These small, 5-inch-long warblers with black-and-white bodies and flaming orange throats pass through southern Maine after spending our winter in the Andes (these were a very common species on the trip Maine Audubon led to the Ecuadorian Andes last November). Among the 20+ species of warblers we see passing through during migration, the blackburnian (especially the bright males) tend to elicit the loudest “oohs” and “ahs” from our groups. Surprisingly, we missed them this year in Portland’s Evergreen Cemetery during the two weeks of walk we led. But traveling a bit farther afield, we found these in abundance: I led walks at the Acadia Birding Festival and Rangeley Birding Festival, where these were some of the most numerous songbirds we saw. In a couple of weeks, I’ll be bringing a group of teenagers from the Hog Island Audubon Camp in midcoast Maine up to Borestone Mountain in Elliotsville, and the hike up the access road will have blackburnians all throughout the spruces.
More commonly encountered around the state is the aptly named common yellowthroat, which has the highest “frequency” as reported on eBird, a contributory science project run by the Cornell Lab of Ornithology. Frequency is measured by looking at all the reports submitted across the state and determining which percentage of those include the species of interest. At their peak, common yellowthroats are reported with about 44% frequency, while blackburnians only top out around 10%. An interesting thing is to watch this percentage drop as we go into the breeding season. In July, when these birds are at the height of their nesting, blackburnian frequency drops to 4 percent and yellowthroats below 30%.
It may seem counterintuitive that when there are arguably the most of these birds around, not just the adults that arrived in the spring, but now the adults plus the three to five chicks they are raising, their frequency drops so much, but that is because they don’t want to be detected. They are being quiet — not singing as much — and spending most of their time caring for their young, so they don’t want to be found by any potential predators (including humans).
This is a good segue to one of the most important things to remember this time of year: there are baby birds everywhere. Most birds go through a very awkward stage of life where they will leave their nests before they are fully capable of flight and they will still be dependent on their parents for food. Remember that this is a natural process for them, so if you stumble upon one, it is almost always best to leave it alone. Adults don’t want to return if you are nearby, so leave baby birds where you find them and move on. Only if a bird is visibly injured should you call a licensed rehabilitator and follow their instructions: do not feed the birds or try giving them water.
Even if it sounds like we are going into the summer doldrums, there are hundreds of birds out there raising the next generation to fill our skies. As always, I encourage you to join one of the many walks that Maine Audubon and our chapters lead around the state and see for yourself the wildlife diversity out there.
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.