The Hills Are Alive With Sound of Mating

Valentine’s Day may be past, but the songs of love are only just beginning to be heard in the county’s parks and other wooded areas. With the spring breeding season drawing near, the hills are alive with the sound of birds.

Birds make simple calls all year, but now is the time that the males of many species break into song as they mark territory and attempt to attract mates. February and March are the peak song months for the county’s year-round residents, such as California thrashers, rufous-sided towhees and wrentits; by late March and particularly in April, the air will be filled with the songs of migrating warblers and flycatchers.

For bird-watchers, these songs are more than simply the harbingers of spring--they are aural “fingerprints”--a means of identifying birds that can be hard to spot in the trees and brush.

Experienced birders learn to rely on sound as much as on sight--sometimes more. In areas with heavy tree cover, birds are usually heard long before they are seen, and often they are never seen at all. In tropical rain forests, for instance, some of the best birders are known to walk with their eyes to the ground, the better to concentrate on the sounds made by the elusive birds hidden in the dense canopy above.

Even with the recent storms, Orange County is not likely to sprout any rain forests soon. But learning to identify bird sounds is still an important skill in wooded local areas, where “a really competent birder” may initially identify 90% of the birds by voice rather than sight, according to Sylvia Gallagher, bird information chairwoman of the Sea and Sage chapter of the National Audubon Society.

“If I lost my sense of hearing, it would be every bit as bad as losing my eyesight, as far as identification and appreciation of birds,” says Doug Willick, a leading local birder.

For most people, learning to identify birds by sound is more difficult than learning to do it by sight, says Gallagher, who leads an Audubon workshop in birding by ear. “Most people are vision-oriented,” she says.

Bird sounds are difficult to memorize, in part because the patterns are so different from the sounds with which humans normally communicate--speech and music. “The first few are the most difficult” to memorize, Gallagher says. “After that it gets easier . . . . You begin to learn the structure.”

Birding by ear doesn’t come naturally. Gallagher suggests that when out birding, “Every time you hear a sound, find the bird right away.” It may take 10 times or more, but eventually you will come to associate the sound with the bird.

Learning the sounds of common birds helps birders know when they’ve discovered something unusual. An unfamiliar sound may signal the presence of a rare migrant or vagrant, and then it’s a matter of finding the bird and identifying it by sight.

Aural identification of bird species is most useful in wooded or brushy areas, but it can be a handy skill even on the mud flats of Upper Newport Bay or Bolsa Chica, where the birds are easily visible. Some species--long-billed and short-billed dowitchers, for instance--are virtually indistinguishable in their winter plumage and can be positively identified only by their call.

Some marsh birds rarely come out of the grasses and reeds, especially during the day. Willick’s only California encounter with a black rail, for instance, was entirely aural--he never saw the bird, but recognized the distinctive call.

Birds make two categories of sounds. Calls, which are heard year-round, are generally simpler than songs, which are heard mostly in spring. Calls may be used to signal alarm or aggression, or may be used for contact, as between flocking birds, or between mates or parent and chick.

Songs can vary greatly in complexity from species to species, and some birds may have an extensive repertory of sounds. Both songs and calls can be used to identify bird species.

In addition to practicing in the field, birders may also study sounds with the help of audio tapes. Several are commercially available; Gallagher recommends a set published by Houghton/Mifflin that focuses on birds of the West. Another good set, Gallagher says, is one offered by the National Geographic Society as a companion to its popular “Field Guide to the Birds of North America.”

Another entry is reportedly in the works, a companion to the newly updated “Western Birds” guide in the Peterson series.

Once, audio tapes were used extensively to draw reluctant bird species into the open. Now, that practice is seen as potentially harmful in many instances. Using a tape to draw out a rare species such as the endangered least Bell’s vireo, for instance, could lead to higher nest failure; the bird could leave its nest temporarily open to predators, for instance, and continued harassment could cause the bird to abandon its nest entirely.

The video revolution has finally hit birding as well. The Audubon Society has put its name on a series of five videotapes that match audio and video; they are being marketed as study aids for birders.

Many of the shots used in the tapes, however, are still photographs; apparently, at this early stage in the game, there is no good videotape available on many bird species. Gallagher says video may eventually be useful in illustrating bird behavior, which conventional field guides can only describe.

For now, however, she recommends a good field guide and a set of audio tapes.