Tree Swallows are somewhat territorial when nesting and breeding, chasing other Tree Swallows away from their chosen nest cavities and defending a small area around them. You see them a handful at a time from the late spring through the summer, but by the end of summer, once they've reared their young, they start to congregate together in large flocks, particularly in the evening.
In one spot in Connecticut, this phenomenon has grown to one of the great natural events of the year: on Goose Island, a small grassy island in Old Lyme, something like 300,000 Tree Swallows gather to roost together each night for a few weeks before it's time to migrate. Savvy naturalists and boat operators have taken notice and now offer Swallow tours of the Connecticut River. This September, Andy and I got a chance to see it all for ourselves.
Roughly 1/2 hour before sunset, Tree Swallows fly in from all over the state—the full radius they're coming from is unknown, but naturalists believe it to be at least thirty miles given the number of birds involved. At first, it's just a trickle of a few birds at a time, but by sunset, the sky is full of hundreds of thousands of them.
Some take brief breaks during this period before roosting, resting lightly on the tops of the phragmites reeds, but they aren't actually bedding down for the night when they do. They're just pausing before rejoining the flock in the air, which grows and grows and grows as the light fades.
It's hard to capture in a photo quite how many birds there are or quite what it feels like to see an entire sky full of deep blue backs and white breasts, all wheeling and turning in a mesmerizing acrobatic frenzy.
There can't be more than a couple of thousand in the photo above, which means I caught less than one percent of them in the frame.
Even this wider angle shot, with its thousands of black dots, just doesn't come close. There's magic to be found in small things, in a patient knowledge of what's already in the sight of your eyes or the reach of your ears. But standing on that deck in the open air with a thousand thousand blue-green jewels winging in patterns too complex to follow was a magic that was impossible to miss. On its own, each bird is impossibly beautiful and dancing an impossibly complex dance. You could watch one swallow and find yourself rapt. So to have three hundred thousand dance at once beyond the realm of possibility even as it's happening a whirlwind through the whole lavender sky.
And then, as if on a signal, they all decide to bed down for the night, and they divebomb like rain into the reeds and disappear in a matter of seconds. And the sky is abruptly as empty as it was full a minute before.