TREE SWALLOWS

   

Tree swallows

Photo courtesy of Sharon Milligan

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Tree swallows are ubiquitous winter birds along the Gulf Coast. Here they dance a frenzied tarantella above the marshes and the beaches in a daylight-to-dusk effort at staying alive until Spring.

When most other insect-eating species are following the sun to more hospitable places, Tree swallows elect to joust with fractious north winds, biting cold, and demoralizing rains, from the coasts of lower New England to the coasts of California. Disaster in proportion to winter weather often results. Those swallows that survive will be gone with the first beckoning glance of Spring.

Before the martins arrive, Tree swallows are the only swallows likely to be seen along the coast in winter. Know them by their white undersides sharply contrasted against iridescent plumage above, which, depending upon light, may appear as metallic green or electric blue.

They are five-inch minimasters of the air as they hawk for insects. As a rule of thumb, Tree swallows fly higher in moderate to good weather when insects are plentiful. In periods of inclement or cold weather, they lower their sights and most often are found just above the salt marshes and above the surface of the water. At such times they often fly below eye level, so intent on the chase that their collision course with the bystander is altered with only inches to spare.

When insect life is diminished, we may see another example of the spectacular aerodynamics of the Tree swallow, at times involving as many as 2,000 or more birds.  This spectacle prompted a number of calls to me last week (this was in 1979) , and was probably the result of the inclement weather with which we are getting so familiar.

It concerns the behavior of Tree swallows at their secondary food source here on the coast – the berries of the Wax myrtle; I have witnessed this flying phenomenon several times, but can find no descriptions of it in the literature.

There are brief references to Bayberry and Wax myrtle as a winter food source for Tree swallows, but incredibly, no mention is made of the nearly poetic manner in which it is obtained. I’d like to take you back to the morning of January 27^th (1979), to a road along Bellefontaine Beach, to describe a sight which my companion that day, Mary Welles of Elmira, N.Y., had never seen in her lifetime of watching birds.

It was very cold and, for the moment, the rain had stopped. Above the large oak under which we stood, a rush of wings filled the air with sounds that could have come from the soundtrack of a science fiction movie. Looking up, we saw that the sky above was thick with Tree swallows massing just overhead. They moved in a concert of whooshing wings, gathering in numbers, (we estimated nearly a thousand) fanning the air above us, and then seconds later they flew as if on signal to form a cloud above a Wax myrtle bush.

Again, they took another cue from some unknown source and funneled down to alight by the hundreds amidst the leaves and branches of the Wax myrtle. Through binoculars, we could see them eating the hard gray berries that grow in clusters. Seconds later they lifted off again so synchronized in movements they were almost as one bird, they swirled into the sky above and returned to the bush in the same funnel-like formation.

We watched this activity for 20 minutes, during which the cloud of swallows in unison, repeated the close order drill in and out of the myrtle until suddenly they dispersed, leaving us filled with awe. Such a sight can be likened only to the movements of small sandpipers, but made more dramatic by its unexpectedness.

This article appeared in the Sun Herald in 1979. Since then, what Judy describes so well has been given a name - “a Tree swallow tornado” –  Many videos have been posted of this phenomenon on YouTube.