Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: SUNDAY, May 15, 1994 TAG: 9405130072
SECTION: EXTRA PAGE: 4 EDITION: METRO
SOURCE: Patricia Held
DATELINE: LENGTH: Medium
Males do most of the singing. Songs help establish, protect and defend his breeding territory as well as help him locate a mate. This is important in species recognition, especially with birds that look alike. For example, the common crow and fish crow are similar in appearance, but their songs differ just enough to tell them apart. Songs are also important for sex recognition. When the sexes of a species are similar in appearance it is more important that their songs differ.
Song helps to coordinate the activities of a mated pair. It strengthens the bond during courtship, nest building, egg laying and incubation. Once the young are born the parents' singing gets much softer and may even cease completely.
Any sounds produced by birds for purposes other than breeding are call notes. These are used to warn area birds of danger and locate other birds for flocking.
Warning calls are usually of a very high frequency with a gradual fade in and fade out. They are almost impossible to locate. When flocking, birds want their location known, so their call has a low frequency with an abrupt beginning and ending. This is important in dense vegetation.
Birds that live in dense vegetation or have inconspicuous coloration depend on song more than those that live in the open or have bright coloration. These birds cannot depend on sight to establish their identities or location. The wood thrush, for example, with its dull brown plumage, would be difficult to locate if it were not for its song. It is a clear beautiful song that sounds like a flute.
In contrast, birds living out in the open depend upon sight identification. The male red-winged blackbird's bright red shoulder patches are more distinguishable to other birds than his coarse "kong-ka-ree" song.
Just as in people, birds of a particular species have dialects. Songs vary slightly in different parts of the country and to a tuned ear these regional differences are distinctive. Our local yellowthroat sounds slightly different from one found farther north.
Some birds sing several songs, including those of their neighbors. Starlings and mockingbirds naturally mimic the songs of other birds, often to the dismay of tuned-in bird watchers. Other birds will only mimic in captivity. Crows, ravens, parrots and magpies will learn that by producing particular sounds they will receive attention. Scientists believe that these birds use this attention that they receive from humans as a replacement for normal social contact with other birds.
While dawn is the key time for many birds to do their singing, some birds prefer the pre-dawn hours, dusk or even late evening. Others sing incessantly all day long.
Because birds can be rather illusive creatures, birders have found that a knowledge of bird songs can help identify different species. While individual species may have different calls and songs, depending upon the situation, there are certain songs and calls that are distinct enough for us to remember them and help us identify the bird just by its song. If, just at dusk, you hear a very deep "hoot-hoot-hoot-hoot," you can almost be positive that a great horned owl is nearby. Some birds are easy to remember because they seem to sing their name. Killdeers sing "kill-deah," and bobwhites will repeat "bob-bob-white." Others sing such a distinct song that it almost sounds like they speak English. "Drink your tea" means a towhee is nearby and a "teacher-teacher-teacher" song is a sure sign of a yellowthroat.
Spring is the best time to hear this wonderful concert. So get outside and open your ears as our local birds fill the air with their songs.
Patricia Held will respond to readers' questions on the plant and animal wildlife in the region. Mail inquiries to: Patricia Held, P.O. Box 65, Goode, Va. 24556.
Patricia Held is a Bedford County free-lance writer and author specializing in natural history.
by CNB