Latest in a series of posts on the Swifts
“When I read the news and grieve, my mind has more than once turned to vesper flights, to the strength and purpose that can arise from the collaboration of numberless frail and multitudinous souls.”
A day off for most of us.
Gadfly imagines you with morning coffee or tea and toast.
With time to read.
To think of the Swifts and the value of community.
The value of vesper flights far above the madding crowd where we pool our separate selves in this fractured time to chart our common societal journey.
On warm summer evenings, swifts that aren’t sitting on eggs or tending their chicks fly low and fast, screaming in speeding packs around rooftops and spires. Later they gather higher in the sky, their calls now so attenuated by air and distance that to the ear they corrode into something that seems less than sound, to suspicions of dust and glass. And then, all at once, as if summoned by a call or a bell, they fall silent and rise higher and higher until they disappear from view. These ascents are called vespers flights, or vesper flights, after the Latin vesper for evening. Vespers are evening devotional prayers, the last and most solemn of the day, and I have always thought “vesper flights” the most beautiful phrase, an ever-falling blue.
Their vesper flights take them to the top of what is called the convective boundary layer. The C.B.L. is the humid, hazy part of the atmosphere where the ground’s heating by the sun produces rising and falling convective currents, blossoming thermals of hot air; it’s the zone of fair-weather cumulus clouds and everyday life for swifts. Once swifts crest the top of this layer, they are exposed to a flow of wind that’s unaffected by the landscape below but is determined instead by the movements of large-scale weather systems. By flying to these heights, swifts cannot only see the distant clouds of oncoming frontal systems on the twilit horizon, but they can also use the wind itself to assess the possible future courses of these systems. What they are doing is forecasting the weather.
Migratory birds orient themselves through a complex of interacting compass mechanisms. During vesper flights, swifts have access to them all. At this panoptic height, they can see the scattered patterns of the stars overhead, and at the same time they can calibrate their magnetic compasses, getting their bearings according to the light-polarization patterns that are strongest and clearest in twilit skies. Stars, wind, polarized light, magnetic cues, the distant stacks of clouds a hundred miles out, clear cold air, and below them the hush of a world tilting toward sleep or waking toward dawn. What they are doing is flying so high that they can work out exactly where they are, to know what they should do next. They’re quietly, perfectly, orienting themselves.
Swifts don’t make these flights alone. They ascend as flocks every evening before singly drifting down, while in the morning they fly up alone and return to earth together. To orient themselves correctly, to make the right decisions, they need to pay attention not only to the cues of the world around them but also to one another. Swifts on their vesper flights are working according to what is called the many-wrongs principle. That is, they’re averaging all their individual assessments in order to reach the best navigational decision. If you’re in a flock, decisions about what to do next are improved if you exchange information with those around you. We can speak to one another; what swifts do is pay attention to what other swifts are doing. And in the end it can be as simple as this: They follow one another.
Thinking about swifts has made me think more carefully about the ways in which I’ve dealt with difficulty. When I was small, I comforted myself with thoughts of layers of rising air; later I hid myself among the whispers of recorded works of fiction, helping myself fall asleep by playing audiobooks on my phone. We all have our defenses. Some of them are self-defeating, but others are occasions for joy: the absorption of a hobby, the writing of a poem, speeding on a Harley, the slow assembly of a collection of records or shells. “The best thing for being sad,” said T.H. White’s Merlyn, “is to learn something.” As my friend Christina says, all of us have to live our lives most of the time inside the protective structures that we have built; none of us can bear too much reality. And with the coronavirus pandemic’s terrifying grip on the globe, as so many of us cling desperately to the remnants of what we assumed would always be normality — sometimes in ways that put us, our loved ones and others in danger — my usual defenses against difficulty have begun to feel uncomfortably provisional and precarious.
Swifts have, of late, become my fable of community, teaching us about how to make right decisions in the face of oncoming bad weather. They aren’t always cresting the atmospheric boundary layer at dizzying heights; most of the time they are living below it in thick and complicated air. That’s where they feed and mate and bathe and drink and are. But to find out about the important things that will affect their lives, they must go higher to survey the wider scene, and there communicate with others about the larger forces impinging on their realm.
Not all of us need to make that climb, just as many swifts eschew their vesper flights because they are occupied with eggs and young — but surely some of us are required, by dint of flourishing life and the well-being of us all, to look clearly at the things that are so easily obscured by the everyday. To take time to see the things we need to set our courses toward or against; the things we need to think about to know what we should do next. To trust in careful observation and expertise, in its sharing for the common good. When I read the news and grieve, my mind has more than once turned to vesper flights, to the strength and purpose that can arise from the collaboration of numberless frail and multitudinous souls. If only we could have seen the clouds that sat like dark rubble on our own horizon for what they were; if only we could have worked together to communicate the urgency of what they would become.