June is a wonderful time for birders with the air filled with the marvelous songs of many species. The morning chorus is truly a feast for the ears.

Let’s start by considering the important distinction between a bird song and a bird call. Songs are complex vocalizations, usually associated with reproduction. Males sing and females typically do not although northern cardinal and painted bunting females are among the exceptions to the rule.

Calls on the other hand are simple vocalizations, usually given by all members of a species. The calls are generally instinctive so do not need to be learned. Calls can be used to keep contact with other flock members and to sound alarms.

The largest order of birds is the passeriformes, often shortened to the passerines. The passerines comprise 60 percent of all bird species. The passerines are subdivided into two major groups: the suboscines (flycatchers and their relatives) and the oscines (songbirds). Suboscines have very simple songs like the “FEE-bee” song of the eastern phoebe. The songs of suboscines are innate so do not need to be learned. Oscines generally learn their complex song from their father or a neighboring male.

Songbirds comprise some 4,000 species, many of which are vocal virtuosos. However, songs are known in other orders of birds. Hummingbirds are one such group. Anna’s hummingbird has a 10-second song, pretty impressive for such a small bird.

Last week I wrote about the cheating that often goes on with birds in a seemingly monogamous relationship. Not surprisingly, bird song plays a role in these soap operas. A male sings for two reasons: to attract females to his territory and to warn other males to stay out.

In some birds, distinctive songs are sung for these two functions. The black-throated green warbler provides a nice example. Male song is often written as “zee-zee-zee-zoo-zee” with the final zee given with great emphasis. This song is referred to as the accented song. It is sung for the purpose of attracting a female. The male is essentially proclaiming his bachelor status and desire to enter into a relationship.

An alternate song is heard that can be rendered as “zee-zee-zoo-zoo-zee” or “trees-trees-whispering-trees.” This is called an unaccented song and is directed at neighboring males to deter them from visiting the singer’s territory and perhaps mating with his partner.

Visit www.allaboutbirds.org and search for black-throated green warbler. Click on the sound tab. The first song is the accented song and the second is the unaccented song.

Chestnut-sided warblers provide another example of males that have both an accented and unaccented song. The accented song is often written as “pleased-pleased-pleased-to-MEETCHA”. The unaccented song lacks the explosive final two syllables. The allaboutbirds.org site has a recording of the accented song.

Some songbirds vary their song over the course of a day. American robins are usually the first local species to start singing in the morning, often as early as 3 a.m., much to the dismay of would-be sleepers. The song of a robin is a series of two- and three-note phrases, delivered in a sing-song style. The dawn version is generally faster. The birds also include a soft, whisper-like phrase that is aptly described as “hisselly”. During the later part of the day, the song is sung more slowly and the “hissely” phrase disappears. We have no idea at this point of the importance of the “hissely” phrase. Allaboutbirds.org has recordings of the dawn and the daytime songs.

Eastern phoebes sing their fairly simple “FEE-bee” song most of the day. However, early in the morning they add an extra syllable, to sing “FEE-buh-bee.” Listen for that variation from your local phoebe.

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

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