A hermit thrush. Credit: Courtesy of Bob Duchesne

The majority of birds are considerate. They sing from exposed perches, or flit around where they are easy to see.

Alas, some birds make it tough for you to view them, and these include some of the most musical species. You can hear them easily, but they lurk inside the forest, refusing to show themselves. They’re a loud mystery.

I would list the ovenbird as one of the worst offenders. This ground-feeding, ground-nesting warbler has a loud song that is usually characterized as sounding like a crescendo of  “Teacher, Teacher, TEACHER.” They’re everywhere, but generally out of sight, calling from back in the woods.

Worse, ovenbirds are among the most aggressively territorial birds. They won’t hesitate to challenge any other ovenbird that ventures too close. Thus, they’re all spread out, usually no closer than 100 yards from each other. Worst of all, they’re a dull, streaky brown, making them even tougher to see. But they’re common, and they live near you.

Winter wrens are the most musical birds in North America. Their beautiful songs invariably come from a secluded spot in the woods. It’s hard to believe that such a long, loud song comes from such a tiny bird, one no bigger than your thumb.

They are forest birds, uncomfortable in town, but the woodlot doesn’t have to be big. Many are in Bangor City Forest, regularly heard in the woods beyond the Orono Bog Boardwalk.

Winter wrens are also streaky brown, making them harder to see in the forest. See the trend? Streaky brown coloration is a good defense for birds that prefer to sing in the shade.

Thrushes are the worst. Not all thrushes. Robins and bluebirds are members of the thrush family, but they stay out in the open where camouflage doesn’t do them much good. However, four other thrushes delight in making identification more difficult. They sing in the woods, usually out of sight.

I daresay the hermit thrush confuses more people than just about any other bird in Maine. They are common, widespread, easy to hear, and hard to see. They are chiefly responsible for the melodic, flute-like song that most people hear coming from the woods, especially at dawn and dusk. When you hear it next — and you will — notice how their short song can go up or down in pitch at the end.

Hermit thrushes are found throughout Maine. They are comfortable in any forest that is not too cold or damp.

Cold and damp forests belong to the Swainson’s thrush. Although its range extends statewide, the Swainson’s thrush is more apt to be found along the Down East coast, up in the north woods and at higher elevations.

Hermit thrushes don’t go very far south for the winter. They return in late April. Swainson’s thrushes winter in the tropics, and take longer to return. They should be arriving, well, right about now.

The Swainson’s thrush also has a flute-like song. It’s like the hermit thrush, but raspier, and always rising — “Weezle, wazzle, woozle.” The ethereal quality of thrush songs comes from a special vocal adaptation.

Humans have a larynx, which allows us to sing one note at a time. Thrushes have a syrinx — essentially a second voice box — that allows them to sing two-note chords, in haunting harmony. The word comes from the Greek word for pan pipes, an instrument that can play multiple notes simultaneously.

The veery is also blessed with a syrinx. Its flute-like song is a cascade of “Veery, veery, veery” chords that fall in pitch. This thrush, too, is widespread in Maine.

It shows a preference for deciduous forest, often a dry woodland floor near water. Although not typically found in town, they are often heard in Mt. Hope Cemetery, on both ends of the footpath around Essex Woods in Bangor, and in Bangor City Forest.

Last, but not least, many people think the wood thrush is the champion singer among thrushes. Its song is similar to the hermit thrush, but it’s a little shorter and ends in a rattling “teeee” that can also rise or fall at the end. It’s sort of an “eee-oh-lay-teeee.”

This is definitely a deciduous forest bird. It’s more common south of Maine, but I have heard them as far north as Aroostook County, and I was surprised to find a cluster of them in Jackman last summer.

All four of these brown thrushes are the same size, a bit smaller than a robin. All are streaky and sneaky, singing from just inside the woodland edge. Mystery solved.

Bob Duchesne, Good Birding

Bob Duchesne serves as vice president of Maine Audubon’s Penobscot Valley Chapter. He developed the Maine Birding Trail, with information at mainebirdingtrail.com. He can be reached at duchesne@midmaine.com.