Fleeting flights

Much of what we experience in nature is fleeting. Right now, in northern Illinois, the first hints of leaves are emerging on the deciduous trees. I love that look. The new leaves display a bright mint-green shade that is like a blush of vivid fresh color on the branches. I also appreciate that the leaves, still so small, aren’t obscuring my view of birds singing on the trees’ limbs. Charming patches of wild violets are gracing our yard with their heart-shaped leaves, white petals and violet centers. I admire these early bloomers so much we delay starting our seasonal lawn mowing until they begin to fade away. Today it rained, and few scents are as recognizable as the organic, musty aroma of the ground after a shower. It seems as though you can smell the teeming life rising up from the earth. Yet none of those glories enchanted me as much as seeing tree swallows over the Fox River this past week.

Never before had I witnessed a flock of migrating tree swallows feeding over water. The first species of the swallow family to head north to their nesting grounds in North America, they arrive here having made a long trek from as far south as Central or South America. Although our area is well within their breeding range, the flocks I watched were clearly migrants, spending part of the day over the river to gorge on flying insects before continuing their northbound journey.

Many people view the arrival of migrating tree swallows a wonderful harbinger of the season of renewal, and now I know why. They travel in large flocks and will stop to refuel, often near or over water where insect life abounds. Here’s what makes seeing them so exciting: they catch insects in the air while in flight. Think about that. Bugs are flitting all around in wildly unpredictable patterns, sometimes directly above the surface of the water, and they have to catch them in their beak in midair. It’s a tall order, which is why swallows are considered among the most agile fliers of the bird kingdom.

The first day I witnessed them, I approached the pedestrian bridge to cross the river and became aware of a sizable number of small birds over the water. I positioned myself in the middle of the bridge and watched countless birds, probably hundreds of them visible from where I stood, flying over the river in dizzying, erratic motion at high speed. My perspective from the bridge enabled me easily to identify the birds as tree swallows. Looking down on them as they swept over the river’s surface, I could easily see the gorgeous, striking blue-green color of their heads and backs flashing their iridescence in the sunshine, along with the brilliant pure white of their undersides as they abruptly turned or streaked overhead. These birds are built for aerial agility. Sporting slender, streamlined bodies and long, pointed wings, the swallows have an aerodynamic shape that enables them to catch insects while on the wing. Their midair feeding is aided by their ability to open their small beaks wider than many other songbirds. Their flying prowess also gives them a fighting chance to escape predators; unlike many songbirds, the swallows migrate during the day, rather than at night.

To describe what they were doing simply as “flying” seems like a major understatement. Verbs like swooping, careening, zooming, diving, gliding, darting, speeding, skimming, circling, plummeting, zipping, whirling, flashing – in combination – begin to describe their movements in flight. It was like watching an elaborate, complicated aerial ballet, but with no discernible pattern to the figures. I was amazed that none of them slammed into each other as they executed their highly acrobatic maneuvers. As they zoomed both over and under the bridge, I was occasionally startled when one of them would whoosh right by me, very close to my head. I wanted to fix my gaze on one bird to follow its intricate movements, but they were moving so fast it was hard to do. When I finally succeeded, I observed my chosen swallow make a wide arc over the water, plummet down close to the water’s surface before sweeping back upward just in time and making a sharp 180-degree turn in one direction or another. Here is a short video to give you a ground-level view of a flock of swallows feeding while airborne.

I observed a second flock taking its meal break over the Fox River two days later, spending another 30 minutes watching them, captivated, do their aerial dancing from my viewing spot on the bridge. Since then, some days have gone by, and no other flocks have appeared. I suspect they have moved on to points north.

Many of nature’s gifts are as fleeting as the swallows’ flight. While it would be impossible for me to remember all of the intricate details of what I witnessed those two days, I will long recall my feelings of awe and delight as I watched the tree swallows freely sharing their gifts with me.

“Swallows” by Leonora Speyer

They dip their wings in the sunset,
They dash against the air
As if to break themselves upon its stillness:
In every movement, too swift to count,
Is a revelry of indecision,
A furtive delight in trees they do not desire
And in grasses that shall not know their weight.

They hover and lean toward the meadow
With little edged cries;
And then,
As if frightened at the earth’s nearness,
They seek the high austerity of evening sky
And swirl into its depth.