Air Date: Week of September 18, 2026

During the Northern Hemisphere’s summer, tree swallows inhabit much of the Western and Northern United States and most of Canada. But come fall, these birds migrate to the Gulf Coast, the Caribbean, and Central America. (Photo: Mike Hamilton, CC)

BirdNote’s Mary McCann recounts the magical aerial dance of the tree swallows. Living on Earth’s Paloma Beltran commemorates Mary McCann’s beloved voice and over 700 BirdNote segments after her passing on August 7, 2026.

Transcript

BELTRAN: Autumn is here in the Northern Hemisphere, and the days are growing noticeably shorter. But many of the songbirds of the summer are still with us, and as Mary McCann points out in today’s BirdNote, they continue to put on spectacular shows.

BirdNote®
Tree Swallow Roost –
The Swarm in Connecticut

[MULTIPLE TREE SWALLOWS CALLING; WAVES LAPPING AGAINST A BOAT]

As the sun sets over the Connecticut River, an astounding natural spectacle unfolds. As many as 300,000 sparkling blue swallows—Tree Swallows—wing their way from miles around, to roost for the evening on Goose Island, near Old Lyme.

[MULTIPLE TREE SWALLOWS CALLING; WAVES LAPPING AGAINST A BOAT]

The birds gather on the wing in one immense, tightly choreographed flock, a swirling mass that changes shape from one second to the next, like an immense silken banner or plume of smoke racing with the wind. With dusk at hand, the aerobatic flock – now shaped like a tornado – swoops down into the island’s tall reeds. It takes but 15 seconds for the 300,000 birds to vanish into the marsh, where they
remain until dawn.

[CALL OF TREE SWALLOW FLOCK]

Roger Tory Peterson, dean of American birdwatching, wrote of the swallows: “I have seen a million flamingos on the lakes of East Africa and as many seabirds on the cliffs of the Alaska Pribilofs, but for sheer drama, the tornadoes of tree swallows eclipsed any other avian spectacle I have ever seen." *

[TREE SWALLOWS CALLING]

Soon all of Goose Island’s swallows will disappear below the southern horizon for the winter. But witnesses will long remember the autumnal spectacle of the birds’ massed flight.

[TREE SWALLOWS CALLING]

Tree Swallows coast to coast are swirling down to roost this month. Maybe there’s a roost near you.
I’m Mary McCann.
###
Written by Bob Sundstrom
Call of Tree Swallow flock provided by The Macaulay Library at the Cornell Lab of Ornithology, Ithaca, New York. Song recorded by
G.F. Budney. Massive flock sounds recorded by O.H. Hewitt.
Producer: John Kessler
Executive Producer: Chris Peterson
© 2008-2017 Tune In to Nature.org September 2017 Narrator: Mary McCann
Tree Swallow photo by Dan Dzurisin https://www.flickr.com/photos/ndomer73/2544385868/
Tree Swallows coming to roost, by Dan Irizarry https://www.flickr.com/photos/danirizarry/6628440837/

*Peterson quotation taken from RiverQuest tour ad for swallow trips.

BELTRAN: For many years you’ve heard Mary McCann’s warm and lively voice on Living on Earth in BirdNote segments just like this one. But we are saddened to share that on August 7th, 2026, Mary passed away at the age of 70 after battling bone cancer. Over the years, Mary McCann brought over 700 BirdNote segments to life, and her beloved voice will live on. And we’d like to think she’s out there somewhere, soaring with the tree swallows and other winged wonders. Thanks, Mary, and we’ll miss you.

 

Links

The story about the tree swallows on the BirdNote® website

Cornell Lab of Ornithology: About the Tree Swallow