They performed their arabesques against the pearl sky of early evening. Swooping, diving, twisting, rising flights that left me dizzy as I tried to track an individual bird among this feeding flock.

Flittering patterns of black and white erupted with blue-green flashes. The setting sun over my shoulder threw its beams at a perfect angle to reflect off the heads and backs of these swallows and dazzle my eyes with turquoise.

These tree swallows (Tachycineta bicolor) were as active as the evening midges and mosquitoes that were being devoured in this beautiful, deadly dance.

My good luck was holding. The rain had finally cleared, the vise grip of work had loosened temporarily, and the birds were here to delight and distract. Geographically, I was not far from my job, but in truth, I was worlds away. The birds filled their bellies with insects. I filled my psyche with the peace of wild places.

Swallows can sometimes present identification challenges to birders. The bird's aerial displays are often so intricate and fast that gleaning even basic characteristics can be tough.

Some of the nine species of swallows in North America look quite similar, even when you get a good look. Tree swallows are the only species in the East that are clear white below with metallic blue or blue-green upperparts. Their upperparts might appear black in low light. But when the sunshine hits the head, back and wing feathers, the metallic glean is unmistakable.

The birds I had been watching were working a grassy area adjacent to a lake. Because of their foraging method, these birds need open space and a nearby source of water. It can be over a pond, above a meadow or farm field. The water slakes the bird's thirst. It also serves as a nursery for millions of insects.

The bugs were out in full force this evening, providing an all-you-can-eat smorgasbord for the swallows.

Tree swallows forage on the wing. Like all swallows, these birds have relatively short bills. Their mouths are wide, though, making it easier to capture insects in spite of their erratic flights. The swallows use their long, pointed wings to maneuver in extraordinary displays of aerobatic skill.

Tree swallows measure just 5-6 inches from bill to the tip of their tails, but their wingspan approaches 15 inches.

The birds have tiny legs and feet. These are flying machines, all wings, tails and a mouth, perfectly adapted to snare insects on the fly.

Females, until their third year, and males, in their first year, have a dull brown coloration instead of the telltale metallic blue-green. As adults, males and females look alike.

Female tree swallows build a simple nest in a tree cavity or similar opening. They also incubate the eggs.

The adult pairs are monogamous, but the male's contribution is limited to defending territory and providing food for helpless chicks until they fledge.

Depending on weather and other conditions, tree swallows may produce a second brood annually, especially when the insects are plentiful.

A biologist friend once cited E.O. Wilson in characterizing the wild gyrations of insect flight as "adaptive for reproductive success." According to this professional naturalist, insects have evolved complex flying patterns that approximate statistical randomness. With limited speed and non-existent strength, bugs need help surviving. The random flight patterns they have evolved enable the otherwise helpless insects to avoid certain death.

Anyone who has slapped ineffectually at a mosquito or swatted unsuccessfully at a house fly knows what he means. Erratic flight is a literal lifesaver for these insects.

But not always. Tonight, the tree swallows are swooping into and out of swarms of insects. The birds soar upward, pause, and then twist into a turning dive for another mouthful.

Before they are done, the birds will have consumed thousands of bugs.

This reminds me that one of the other evolutionary traits of insects is their breeding productivity. Thousands of midges are being consumed right in front of me, but this loss is overwhelmed by their prodigious numbers.

This quiet little lake is, in reality, a teeming ecological system.

I come to this spot for respite. The centrifugal forces in my life pull me in a thousand random directions. At times I fear that I will simply fly apart. This little haven of water and fields and birds helps to hold my vital center.

Tonight I find even more. With dazzling precision, these tree swallows demonstrate that it is possible to navigate in a world of seeming chaos.

And they do more than simply survive. They thrive and do so with grace. Tree swallows are perfectly adapted for their lives in this chaotic world.

I wonder if my limited skills can be adapted as successfully to the challenges of my whirlwind life.