Chimney Swifts

Chimney swifts are the first birds I remember seeing when I was about five years old. I lived in Lancaster City at the time and saw a group of them fluttering, soaring and twittering across the sky. And when we visited my grandparents in Lancaster, I saw flocks of them careening among each other, without collision, over rows of homes, businesses and streets during summer evenings.

Swifts summer in cities, towns and farm yards in North America where they nest down the inside of chimneys, hence their common name. They arrive in North America during April and migrate south to northern South America in September to spend the northern winter catching flying insects over South American forests. And they spend the bulk of each day, every day of their lives, catching flying insects in the sky. It is then those birds are visible to us.

Before the arrival of European people and their homes with chimneys, swifts nested down the inside of hollow, broken-off trees. These birds probably are more common today than ever in their history because there are many more chimneys in North America to nest in than there ever were hollow trees.

Pairs of swifts break off tiny twigs from trees and "glue" those twigs to the inside walls of certain unused chimneys with their own saliva, to form a platform on which they lay their three to four eggs. The young cling to their platform and are fed flying insects by their parents until they are developed enough to fly up the chimney and out on their own to snare insects from the air as they cruise along.

August is the best time to see great flocks of swifts gathering at dusk, when they are entertaining to watch. They are done raising young then and congregate into large gatherings each evening during that month and into early September, prior to zipping down a large, unused chimney for the night. As dusk deepens each late-summer evening, hordes of swifts swirl around the chimney time after time. Then a few birds dive down that large yawn, then more and more. Soon the whole twirling mass of hundreds, even thousands of swifts goes down the chimney, like smoke in reverse, without the birds colliding with each other. Before long, all the swifts are down the chimney where they cling upright and packed together on the bricks, or stones, with their tiny toenails.

A soaring swift, turning this way and that on stiff-looking, swept-back wings, is shaped like an arrow point shooting across the sky without its shaft. Their bodies, heads and tails seem to be one on long, narrow wings. But swifts don't sail in the wind all the time. They alternately soar and flutter when shooting swiftly across the sky and abruptly turning this way and that while chasing down flying insects.

Look for swifts over cities and towns in summer. They are interesting, and entertaining to watch in the sky

Photo 1 courtesy of Jim McCulloch * Photo 2 courtesy of K. Kendall