Black-Throated Green Warbler
Black-Throated Green Warbler
For the majority of birds, the nesting season is zinging along these days! And so is the Maine Bird Atlassing project. Of the current 175 confirmed species statewide, Lincoln County has 87, with 85 for Knox and 81 for Waldo so far.

Certain species have already produced first clutches of chicks and are preparing to repeat the nesting cycle. Last week I observed an industrious robin pair building a second straw nest above a busy, heavily traveled house porch. Troupes of chocolate-bodied juvenile Starlings, tail-bobbing Eastern Phoebes and swooping Tree Swallows have now taken wing. Eaglet chicks and Red-Tailed Hawks have left the family nests but will continue to solicit food from parents in coming weeks.

Through my involvement in the Atlas project, I’ve witnessed instances of reproductive triumphs and isolated nest failures — like a Yellow Warbler pair whose nest was unexplainably destroyed overnight but who continued to feed their young in an impromptu fashion within a stand of low alders.

Let’s consider two spruce/hemlock warblers that I’ve confirmed as nesting locally: Black-Throated Green and Northern Parula Warbler. From experience, I can attest that nesting birds can be hard to detect in these dense, shadowed habitats. But there is hope. I’m always harping about studying bird behavior as a means to learning their key life habits. This observant practice pays direct dividends at nesting season since parents must provide daily food to nestlings: watch the actions of the parents, learn the eventual whereabouts of their young.

Hearing the Black-Throated Green’s characteristic “zee-zee-zee-zoo-zee” song in a tall white pine tree, I spied an adult male gleaning insects overhead. This species sings persistently during the breeding season. One motivated individual was observed singing 466 songs in one hour. This warbler’s vivid bright-yellow face and contrasting black bib stood out amid the greenery. He went earnestly about his business, skirting through pine, spruce and larch branches to stuff his bill with juicy, nutritious food items. Altas confirmation code: CF= carrying food.

Pinpointing an actual bird nest in a lofty evergreen is like the proverbial needle/haystack equation. And the diminutive Parula Warbler takes things to considerable level of challenge with its obscure little nest hidden in hanging veils of “Old-Man’s Beard” lichen (Usnea moss). Spanish moss is the material of choice in the southern portion of the bird’s range. Built solely by the female, the nest is a small hanging pouch of lichen and twigs, unlined or lined sparsely with soft shreds of moss, grass, pine needles and hair. A round entrance hole is positioned in the top or side of the cluster so nestlings can be attended and fed.

In the tree above my head, the bluish-gray male Parula sang his buzzy ascending trills as the pair fluttered and hung upside down at the edges of branches, probing energetically for insects. After watching the pair’s successive trips to a specific patch of moss, I spotted the globular nest suspended below a stout limb about 20 feet up! The tennis ball–sized nest was so well camouflaged by the draping moss, I lost sight of it temporarily. Both scurrying parents made frequent deliveries to the nest as the gaping bills of two downy chicks stretched skyward. Atlas breeding confirmation: FY = feeding young.

It is likely that several bird species are nested around the vicinity of your home or neighborhood as we speak. Be on the lookout for activity that suggests nesting actions. These should become more obvious in coming weeks as sparsely feathered fledglings make peeping sounds and chase through the foliage behind their parents.