Last month I wrote about the Maine Bird Atlas, a project led by the Maine Department of Inland Fisheries and Wildlife to map the breeding (and wintering) distributions of birds in the state. We needed help to get it finished this summer and long story short, we did it! It was an amazing effort by thousands of volunteers to cover the state. We hit our goals, and now have lots of data to comb through. In the words of our ecological modeler for the atlas, Evan Adams, we need to “turn data into information” but we can already see some obvious trends. I want to highlight a few of these changes here because they’ll help answer a number of the questions we receive regularly.

First, Rick from Palermo recently wrote to us asking about a decline in barn swallows that used to nest in his barn. I want to emphasize that it is often hard to comment on individual instances as there are often too many factors to know exactly what is happening in one restricted area, but Rick’s observation does fit a pattern that the Bird Atlas data is showing. Sadly, most aerial insectivores, especially swallows, are declining across the state. Bank swallows are showing some of the most dramatic declines, as the habitat they use to nest is becoming increasingly scarce. They thrive on disturbance, nesting in sandy slopes and banks, but as flood-control and erosion-control projects increase, there are fewer places for these birds to nest. In contrast, barn swallows seem to have plenty of nest sites available, from old barns to the undersides of bridges, but they are also declining. This, and the declines of other insectivores, is almost certainly tied to declines in insects, especially from pesticide use.

Another obvious change in our breeding birds is the arrival of southern species that weren’t here before. Since the first atlas was done in Maine (which ended in 1983), some new species to establish breeding populations in Maine are red-bellied woodpecker, Carolina wren, fish crow, and orchard oriole. People find many of these species in their backyards and call us at Maine Audubon because “the field guide says they shouldn’t be here.” This is because those field guides were published in (or before) the 1980s. Many of these species have been steadily marching northward as the climate warms.

So these species, at the northern limits of the range, are expanding into Maine. We’re also seeing changes in the other direction: species whose southern limit is in Maine are being pushed north out of the state. Olive-sided flycatchers were breeding across most of the state through the ‘80s, in all counties except York, but have now receded northward into the spruce forests of the western mountains, northern Maine, and just a few sites in Washington County. Boreal chickadees, the brown-capped cousin of Maine’s state bird, have also lost a lot of ground on the southern end of their range. In the last atlas they were breeding across Downeast Maine, in Hancock and Washington counties, but now have almost completely disappeared from that region and only can be found in the northwest third of the state.

There are lots of great conservation success stories to be told, from the increase in bald eagles and peregrine falcons, to the arguably “too successful” reintroduction of wild turkeys. I’ll leave more of those to be told once we have finished “turning the data into information” but until then, I’d love to thank all of the volunteers, technicians, and staff that made this project successful.

FOR NIGHTHAWKS, EYES UP BEFORE SUNSET

One of Maine’s most magnificent migration spectacles can be seen in the evenings late this summer as common nighthawks form large foraging groups as they journey south. We seem to get the most inquiries about this movement of nighthawks after it has already happened, so hopefully this can be a public service announcement to be on the lookout, and serve to encourage anyone who hasn’t seen nighthawks before to step outside and look for them.

Beginning in mid-August, but peaking in the last weeks of August and into September, you can spot common nighthawks migrating south by the dozens, if not hundreds. They can be seen in the final hour or two of sunlight, usually around 5 or 6 p.m., and they favor large open fields and rivers where food is abundant.

As an added challenge, try to gauge the age and sex of the birds you see. Adult males have white patches on their throats, outer sections of the wings, and on their tails. Adult females are similar to the males but lack the white on their tails. And juvenile birds, those born this year, will only have white patches on their wings. Step outside one of these evenings and see if you can spot a nighthawk on its several-thousand-mile-journey to South America.

Do you have a nature question for Doug? 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 a.m., at the Gilsland Farm Audubon Sanctuary in Falmouth.

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