Tree Swallow in September

September is the peak of fall migration. Huge numbers of birds move south on cold fronts, mixed flocks form, and summer residents slip away almost unnoticed. Young birds making their first migration appear in places the species rarely visits.

For the Tree Swallow specifically, September is a fall month of relative routine, with the species settled into its seasonal pattern across its range. Across the 60 states and provinces where tree swallows occur, what the bird is doing this month depends heavily on latitude — the details below break it down by band.

Southern states

absent

Mid-latitudes

year-round resident

Northern states & Canada

absent

In September, tree swallows are absent in the South, year-round resident across the mid-latitudes, and absent in the northern states and Canada. That north–south split is the defining feature of this month: where you live changes which version of this bird you're looking at.

Tree swallows are not nesting in September. The season runs May–June at mid-latitudes.

That makes September a useful month for nest-box work: cleaning out old nesting material, checking mounts and predator guards, and making repairs while boxes are empty. A box that's ready early gets claimed early.

Tree Swallow nest box dimensions and mounting →

• Flies, mayflies and dragonflies

Tree swallows readily take bluebird-style nest boxes; mount boxes in pairs 15–25 ft apart to share with bluebirds.

Migrants passing through may stop at feeders for a day and never return — September rewards watching closely. Natural seed and fruit crops are abundant, so feeder traffic can be uneven.

Full Tree Swallow diet guide → · Best feeder for tree swallows →

Tree swallows are settled and predictable in September, which makes this a good month to learn the bird's routine — same feeders, same perches, same times of day.

If you have a Tree Swallow box up, this is the month to make sure it's clean, secure and ready — the box guide below has the exact hole size and mounting height this species needs.

AlabamaAlaskaAlbertaArizonaBritish ColumbiaCaliforniaColoradoConnecticutDelawareFloridaGeorgiaIdahoIllinoisIndianaIowaKansasKentuckyLouisianaMaineManitoba