Signals of the advancing spring season abound. Choruses of wood frogs clacking from forested vernal pools; hoarse barking grunts of courting gray squirrels echo through the hardwoods. And are you noticing some increasing intensity in bird songs, as well? Several Song Sparrows are establishing breeding territories within earshot of my house as counter-singing males announce their nesting intentions in the pre-dawn hours. Non-singing species find alternate ways to attract a mate, too. Again this spring, a male Yellow-Bellied Sapsucker hammers away on a metal sign on my street, a staccato ratta-tat drumming session. Maybe he’s the same individual who returns here each year to bang on that sign?

In my previous column, I highlighted the new Maine Bird Atlas project that has begun across the state. This five-year project provides unique opportunities to learn more about the birds around you in a more disciplined (scientific?) way. It’s captivating to find a spring bird nest — maybe a robin cloistered in an apple tree or an Eastern Phoebe in the eaves of a porch or shed. Most nests are well-concealed and hard to locate, however; but unearthing occupied nests is not the ultimate objective required to confirm breeding activity. And disturbing active nests for documentation purposes is even less necessary or desirable.

The Atlas protocols utilize a list of evidence-based codes that correlate to specific bird nesting behaviors. Beyond the most obvious scenarios, such as discovering a nest with young (NY) or a nest with eggs in it (NE), other confirmation codes apply as the nesting season progresses. Some examples? FS — Carrying Fecal Sac: nestling songbirds and woodpeckers produce white fecal sacs that contain liquid waste materials in a neat little package that minimizes soiling of nest interiors. The avian equivalent of a diaper, adults carry these sacs in their bills and away from nest sites. CF — Carrying Food: an adult is repeatedly carrying food in the same direction to feed young, such as swallows entering a nest box. (This code should be used with caution for corvids, raptors, gulls, terns and kingfishers that routinely gather food some miles from the actual nest site.) FL — Fledged Young: these are often downy juvenile birds observed while still dependent on adults. Frequently sporting short tail feathers and incapable of sustained flight, they are restricted to the natal area by dependence on adults or limited mobility (baby grouse, baby geese, baby killdeer that can’t fly yet). Thus it is most likely that these individuals originated locally. In such instances, please leave them be and resist the temptation for “rescues.” The parents are usually somewhere in the vicinity gathering food.

There are four categories of evidence-based codes posted on the Maine Bird Atlas website ( that are used to determine Confirmed, Probable, Possible or Non-breeding breeding status.

Another interesting aspect of the atlas is a list of “safe dates,” delineated calendar dates when each species is most likely to be nesting. Since many neo-tropical migrants haven’t arrived yet and other species are merely passing through on their journeys north, we wish to avoid assumptions that birds are nesting in a given area. Safe Dates vary by individual species: for early-season nesters like Bald Eagles, March 16 to July 31 are reliable safe dates; for Song Sparrow, it’s May 10 through August 8; most of the warbler species generally nest between June 1 and August 1.

Volunteers continue to sign up online and adopt atlas blocks. Thus far, 372 blocks have been adopted statewide. In the local St. George section that I will help to coordinate, 22 blocks are already selected. I urge all interested parties to explore the Atlas website and consider adopting a coverage block or contributing incidental sightings.