Tuesday, March 18, 2008

Swallows Are Signs of Spring

Winter appears to be hardly gone when we sight the barn swallow home from Brazil, darting, zipping and twittering in flight. The sighting reminds us how things change for both man and birds, especially environmentally.

When we came to the Central Savannah River Area some five decades ago, there were no barn swallows around, that is that nested in the area. The foothills of the Georgia and South Carolina mountains were the southern limits of their breeding range. As man alters the environment of North America, birds adapt to the changing conditions or decline in numbers. The barn swallow adapted.

This is the second time this species has changed nesting situations. Before our forefathers came to America, these swallows built in tree cavities, rock crevices and caves. But from the time the first Colonists started building barns, the barn swallow, being an opportunists, left tree cavities and rock crevices for buildings, maybe because barns gave better protection from nasty weather. Because of this habit, this flying feathered saucer has become known as the "barn swallow," a name it holds until today.

Many of these forked-tailed birds still nest in barns. But, as our great freeways swept through the countryside, barn swallows followed, nesting under the many bridges that spanned the thoroughfares. This brought them into our area and carried them even farther south.

The barn swallow is perhaps the best known of the 20 plus species of American swallows. Small and trim, it is easily recognized because of its purplish-blue back, red-brown forehead, rich rufous breast touched with white, long pointed wings and its deeply forked tail. The forked tail is a good identification mark, the barn being the only swallow with such a tail. The female is usually duller in colors, but not always.

These sleek birds feed on the wing, never flying a straight line, but circling, darting, and twisting in the air. Holding their tiny wide-gaping mouths fully open like suction cups, they scoop out of the air hundreds of noxious insects, including gnats, mosquitoes, house flies, grasshoppers, crickets, moths and dragonflies.

The nests of barn swallows are semi-circular or cup-shaped and made of mud mixed with sand. The shape depends on whether the nest is attached to a beam or rafter or a flat shelf. The nests are lined with soft materials and feathers, usually chicken feathers. The three to five white eggs have markings of bright reddish-brown and pale lilac.

This handsome swallow breeds over most of North America, nesting from northwestern Alaska to Mexico and from the Atlantic to the Pacific coast, including much of Canada and the United States.

Barn swallows nesting in Alaska will travel 7,000 miles from the sunny pampas of Argentina each spring to nest in North America. Year after year these swift fliers travel the same sky ways to and from breeding and wintering grounds. Yet they have nothing to direct them but that "something" (wild wisdom) that speaks out from the earth or sky to guide them to their destination.

No matter the weather, spring has sprung when the swallows return.