Tree Swallows in Ontario
When tree swallows are present in Ontario, when they nest, which native Ontario plants feed them, and how to host them in a Canadian zones 0a–7a yard.
- Status in Ontario
- Summer breeder
- Nesting window
- June
- Broods
- 1 per season
- Hardiness zones
- Canadian zones 0a–7a (southern Ontario roughly equivalent to USDA 4–6)
- Nest box
- 1 1/2 in hole, 5 × 5 in floor, 5–10 ft
When to expect tree swallows in Ontario
Tree Swallows are summer residents in Ontario, arriving shortly before nesting begins in June and leaving after the young are independent. Through the season they feed on flies, mayflies and dragonflies.
Humid continental in the south, boreal and subarctic in the north; most backyard birding happens in the southern Great Lakes lowlands.
Nesting in Ontario
Across Ontario, tree swallows typically nest from June. Nest site: nest box or tree cavity lined with feathers. Females lay 4–7 eggs, incubate for 11–20 days, and young leave the nest after 15–25 days.
Short, warm summers; Point Pelee and Long Point are continent-famous migration sites.
- Have boxes cleaned and mounted before May — tree swallows begin prospecting ahead of egg-laying.
- Use a 1 1/2 in entrance on a 5 × 5 in floor, mounted 5–10 ft.
- Fit a pole baffle or hole guard; ventilation gaps and drainage holes are essential.
- Clean out old nests after each brood and again after June.
Native Ontario plants that attract tree swallows
Of the regional native plants we track for Ontario, these 8 provide food or cover tree swallows use:
Insects, seeds and cavities.
Fat-rich red fall fruit taken by thrushes, bluebirds and woodpeckers.
Early-summer berries arrive exactly when nestlings are being fed.
Acorns plus hundreds of caterpillar species for nestling food.
Drought-hardy prairie oak with large acorns and a heavy insect load.
Summer fruit and one of the top caterpillar host trees.
Late-summer berry clusters taken by over 40 bird species.
Blue-black fall fruit and dense nesting cover.
Feeding tree swallows through the Ontario year
Tree swallows readily take bluebird-style nest boxes; mount boxes in pairs 15–25 ft apart to share with bluebirds.
- Best foods: Crushed eggshells in spring.
- In Ontario's summer: offer water and insect foods; natural food is abundant.
Full diet breakdown for tree swallows · Best feeder for tree swallows
Frequently asked
Are tree swallows in Ontario year-round?
No. Tree Swallows are summer breeders in Ontario and leave for the winter.
When do tree swallows nest in Ontario?
Nesting in Ontario typically runs June, with 1 per season. Clutches are 4–7 eggs, incubated for 11–20 days.
What native plants attract tree swallows in Ontario?
Sugar maple, Flowering dogwood, Serviceberry, White oak, Bur oak, Black cherry, American elderberry, Arrowwood viburnum are native plants in Ontario that provide food or cover for tree swallows.
What size birdhouse hole do tree swallows need?
1 1/2 in, with a floor of 5 × 5 in mounted 5–10 ft.
Tree Swallows in other regions
Other backyard birds in Ontario
Sources
- Tree Swallow — All About Birds, Cornell Lab of Ornithology
- Tree Swallow life history — Cornell Lab of Ornithology
- Tree Swallow — Audubon Guide to North American Birds
- NestWatch nest box plans and species requirements — Cornell Lab
- eBird region overview and bar charts — Ontario
- Plant Hardiness Zones of Canada — Natural Resources Canada
- Audubon Native Plants Database
- Ontario Breeding Bird Atlas — Birds Canada
Timing reflects typical patterns for the region as a whole; local dates vary with elevation and year. Check the linked eBird bar charts for your county.