Fledging

Swifts, July

Jul 30, 2024

I fell in love with swifts (as one does) the first summer I lived in England under their screaming, swerving dominion of the sky. A few summers later, the first swifts hatched and fledged in the nest boxes attached to the outside of the tower where my PhD office was—part of the David Attenborough Building in Cambridge, which hosts the Cambridge Conservation Initiative. I followed the nestlings’ every milestone on the livestream camera inside one of the nests. I’ve tuned in every summer since. I never get tired of witnessing this intimate miracle, these pink blobs fairy-godmothering into scimitar-feathered birds in just a few weeks, making their restless preparations, and finally dropping unceremoniously out of the nest hole, off to Africa and not to be seen on land for several more years.

Video: Swifts on the wing in Grenoble (sound on)

Common swifts (Apus apus) abound in Grenoble, where they’re called martinet noir. In the surrounding mountains there are also alpine swifts (Tachymarptis melba), called either martinet alpin or martinet à ventre blanc for their white bellies. I watch the French swifts happily from below, but it’s still the Cambridge nest boxes that let me in on the progress of breeding.

Two summers ago I kept a swiftlet diary and posted it on my old Cambridge blog, along with a couple of poems inspired by them. (You can read it here to learn more about swifts in Cambridge.) This summer I didn’t take such detailed notes, but took lots of screenshots of the livestream—which covered two active nests this time—and posted them on Substack Notes.

This year’s chicks fledged around a week ago, and the parents left a few days later. To celebrate, I’m gathering my photos and videos of their milestones here and sharing a revised version of my nestling poem below. Two ways of tracking their mystical unfurling.

Note: if email clips this post, click on the title or “Read in app” to see the whole thing—including the poem at the end :)

Brooding and laying

Mid-May to mid-June: snuggly couple, two perfect eggs

Hatching and feeding

June 11: First feeding

Dinosaur era: pinfeathers and appetite

June 18: Rabid feeding

June 21: Pinfeathers bristling in

June 26: Mobility (and chaos) increasing

June 27: Exploring the nest box

Feathers filling in + flight prep

July 2: fluffy

July 7: Wing exercises have begun in earnest

July 8: Come evening, the whole family sleeps

July 15: Testing wingspan

Looking out

July 17: Much time devoted to looking out at the sky

Fledging

~ July 23: They’re gone.

Text within this block will maintain its original spacing when published

Swifts, July
by Anne Thomas

Their lives are a miracle 
of propulsion and lift.

So yes, there is the endless sky
but folded into nest-box 
is another mystery: 

the magnetic draw of brood
the slowing of blood
the quickening of egg
the frail pink bodies 
that will tick inexorably, 
featherwise, toward sky. 

But first they must feed.
They must grow into 
their bulbous eyes
their scaled pinfeathers
their pale wet gapes
flint-tipped trawling triangles 
of want.

Squinting, they learn light 
until they blink their parents'
obsidian-glint
in fierce luminous alcoves.
Wings stretch full fan
in a thicket of curving points 
come evening 
when the whole family sleeps.

They brave the teetering edge 
of nest-haven. Feathers fill in
while they look out
considering their inheritance:
space, boundless, streaked 
with screaming speed.

This is decreed,
the sitting and looking,
by the same force that lengthens
feathers, tests wings 
against narrow nest-walls:
the quickening.

When they go
dropping suddenly into light
they won’t land again
until the brood-call. 
A year, two, three
over Africa and ocean
then nest
then sky again:

The universe 
and its soft crowded core.

Their blood knows.
They are almost ready.