A swirling mass of tree swallows twisting through the sky like a small tornado has been making the rounds online, and the footage shows tree swallows during fall migration in Massachusetts. The footage, shared by the U.S. Department of the Interior, shows the birds gathered into what's being called a “birdnado” as they stage for their journey south.
The clip was highlighted in a video segment titled “Birdnado” video shows tree swallows in fall migration, published by CBS News Boston. According to that report, the swirling formation captures tree swallows in the midst of their fall migration, a phenomenon tied to the Parker River National Wildlife Refuge Complex, which sits in Massachusetts.
Why These Birds Swarm Before Heading South
Tree swallows don't just take off for warmer climates the moment nesting season ends. Most of them first relocate to large marshes, where food is abundant and nighttime roosting is safer, according to treeswallows.com. The birds primarily feed on flying insects but will also eat small berries and seeds, the site notes, giving them flexibility as insect supplies shift with the season.
From those marshes, the birds typically move through stopover or staging areas before continuing on, per the same source. During this staging period, flocks can swell from the hundreds into the hundreds of thousands, treeswallows.com reports — which helps explain how a gathering of birds can look dramatic enough to earn a nickname like “birdnado.”
A Slow-Motion Journey South
Despite the urgency suggested by a swirling cloud of birds, tree swallows gather into large flocks before migrating south, according to treeswallows.com. Columbus Audubon adds that the birds gather into large flocks in late July and August, often congregating where food is abundant, before migrating south in groups that assemble at dedicated staging areas.
That staging behavior isn't unique to Massachusetts. Columbus Audubon notes that sites like Big Island Wildlife Area and the Hebron Fish hatchery near Newark, Ohio, can see tree swallow flocks numbering in the hundreds or even thousands. The group also points out that a pulse of migrating Canadian birds often passes through in mid-September to early October — right around the timeframe when this latest video surfaced.
Similar spectacles have been documented elsewhere in past years. An observer writing on Nature Walks With Judy described seeing huge flocks of tree swallows blanketing an island over the course of several weeks, landing on beaches and nearby wires before taking to the air again. That same account described the birds forming murmuration-like flocks that swoop and shift into shapes across the sky, a description that lines up with the “birdnado” imagery circulating now.
Free Program Puts a Spotlight on the Species
Locals curious to learn more about the swirling migrants don't have to wait long. The Friends of Parker River National Wildlife Refuge has announced a free program called “Tree Swallows, Tiny Superheroes,” set for Saturday with no registration required. The talk will be held at the Parker River NWR Visitor Center, located at 6 Plum Island Turnpike in Newburyport.
The group behind the event is the Friends of Parker River National Wildlife Refuge. For anyone who has watched the birdnado footage and wondered what exactly they were looking at, Saturday's session offers a chance to get some answers straight from a local expert as the tree swallows continue their slow march toward warmer skies.
