The morning chorus of bird song is a phenomenon we associate with summer. Male songbirds sing vigorously then to attract a mate and ward off other males. One of the joys of birding is learning to identify singing males by their species-specific songs.

Outside of the breeding season, males typically don’t sing. But most birds have distinctive call notes that are used to communicate with other members of their species. Birders can use these call notes to identify birds in the winter.

This winter is shaping up as a great one for the irruptive winter finches. All of our finches call frequently. Their call notes are among the most difficult of our winter birds to learn but well worth the effort. Finches are very mobile, social birds. Flocks often pass over at fairly high heights, too high to permit identification through binoculars. Knowing the call notes can clinch an identification.

Our most familiar finch is the American goldfinch. In flight, goldfinches give a call note that can be represented as “per-chick-o-ree” or “potato chip.” Goldfinches also give a rather whiny “chi-ee” call as well. The scientific name of the goldfinch, carduelis tristis, reflects the sound of this call; tristis is Latin for sad, an apt description of the call note.

The pine siskin, like the goldfinch, is a small finch with an absolutely distinctive call. It’s a buzzy note that screeches upward. Think of it as an upslurred “zreeee.”

A third small finch, the common redpoll, can be easily confused with the American goldfinch by its calls. The typical flight call is a “chit chit” or “chit chit chit.” Redpolls also have a note that sounds like the sad, whiny note of the goldfinch.

Two medium-sized finches, the house finch and the purple finch, occur regularly in our area. It’s easy to study the calls of house finches as they are very common at feeders. Their call can be written as “cheet.” It is a sweet note, often repeated several times when a bird takes flight.

The purple finch has a much softer call note. Usually given in flight, the note can be described as a soft “pit.”

I devoted the last two columns to two species of grosbeaks that are widespread in Maine: the evening grosbeak and the pine grosbeak. Both call frequently in flight and often fly well above treetops. The evening grosbeak’s call is sometimes written as “cleer” or “cleep.” The note carries well. Words aren’t adequate to describe the sound of this call. Once heard, it will become one of the most distinctive ones you will encounter birding.

The pine grosbeak has a softer call. Usually these birds give a two- or three-note whistle with the second note having the highest pitch. This whistle is a beautiful call that evokes images of the snow-covered North Woods. In flight, a soft trill is often heard as well.

I will end with brown creepers, cryptic yet surprisingly common birds in Maine. Their mottled brown plumage on their upperparts makes them magically disappear as they forage on tree trunks. However, their presence is often revealed to an experienced birder by their high-pitched, buzzy “seet” note. One you learn to recognize this call note, you will be surprised how often you will detect the presence of a brown creeper. Seeing one is another matter.

Learning bird notes by reading descriptions of what they sound like is a challenge. It’s much better is to let the birds be your teachers. When you hear a call you don’t recognize, track the bird down and identify it by sight.

There are lots of good commercial recordings of bird sounds. A wonderful website that provides multiple sound recordings for each species is can be found at: (http://www.allaboutbirds.org/).

Herb Wilson teaches ornithology and other biology courses at Colby College and perches in South China. He welcomes reader comments and questions at:

whwilson@colby.edu