Nest boxes · Ontario

Birdhouses for Ontario

21 cavity-nesting birds breed in Ontario. The first starts nesting in February, so the box season opens in January.

Local conditions

Growing zones: Canadian zones 0a–7a (southern Ontario roughly equivalent to USDA 4–6)
Winter: Cold, snowy winters; feeder flocks are dominated by chickadees, nuthatches, woodpeckers and finches.
Summer: Short, warm summers; Point Pelee and Long Point are continent-famous migration sites.
Box nesters: 21 (15 year-round residents)
Hole sizes needed: 15 distinct

Humid continental in the south, boreal and subarctic in the north; most backyard birding happens in the southern Great Lakes lowlands.

Box calendar for Ontario

Bird	Status	Hole	Height	Up by	Nesting	Clean out
Barred Owl	Year-round resident	7–8 in	12–20 ft	January	February–May	June
Hooded Merganser	Year-round resident	4 × 3 in oval	6–20 ft	February	March–May	June
Tufted Titmouse Extreme southern Ontario only.	Year-round resident	1 1/4 in round	5–15 ft	March	April–June	July
White-breasted Nuthatch	Year-round resident	1 1/4 in round	5–20 ft	March	April–June	July
Eastern Screech-Owl	Year-round resident	3 in	10–30 ft	March	April–May	June
American Kestrel	Year-round resident	3 in	10–30 ft	March	April–June	July
Wood Duck	Year-round resident	4 × 3 in oval	6–20 ft	March	April–June	July
Northern Saw-whet Owl	Year-round resident	2 1/2 in	10–20 ft	March	April–June	July
Eastern Bluebird	Summer breeder	1 1/2 in round (1 9/16 in for Mountain/Western overlap)	4–6 ft on a baffled pole	April	May–August	September
Black-capped Chickadee	Year-round resident	1 1/8 in round	5–15 ft	April	May–July	August
Purple Martin Southern Ontario.	Summer breeder	1 3/4–2 1/8 in round, or starling-resistant crescent (3 × 1 3/16 in)	10–20 ft on a telescoping pole, 40+ ft from trees	April	May–July	August
Downy Woodpecker	Year-round resident	1 1/4 in round	5–20 ft, box packed with wood shavings	April	May–July	August
Hairy Woodpecker	Year-round resident	1 1/2 in round	8–20 ft, box packed with wood shavings	April	May–June	July
House Wren	Summer breeder	1 to 1 1/8 in round	5–10 ft near shrubs	April	May–August	September
Carolina Wren Extreme southern Ontario.	Year-round resident	1 1/8–1 1/2 in	5–10 ft	April	May–August	September
Red-bellied Woodpecker	Year-round resident	2 1/2 in	12–20 ft	April	May–July	August
Northern Flicker	Year-round resident	2 1/2 in	6–20 ft	April	May–June	July
Prothonotary Warbler Extreme southwest; endangered in Canada.	Summer breeder	1 1/8 in	3–6 ft over water	April	May–June	July
Red-breasted Nuthatch	Year-round resident	1 1/4 in	5–15 ft	May	June–June	July
Tree Swallow	Summer breeder	1 1/2 in	5–10 ft	May	June–June	July
Great Crested Flycatcher	Summer breeder	1 3/4 in	8–20 ft	May	June–July	August

Nesting windows are shifted from each species' mid-latitude season by Ontario's latitude; year-round residents may also roost in boxes over winter, so clean them out in autumn and leave them up.

Frequently asked

When should I put up a birdhouse in Ontario?

By January for the earliest local nester, the Barred Owl, which starts nesting around February.

Which birds use nest boxes in Ontario?

Barred Owl, Hooded Merganser, Tufted Titmouse, White-breasted Nuthatch, Eastern Screech-Owl, American Kestrel, Wood Duck, Northern Saw-whet Owl, Eastern Bluebird, Black-capped Chickadee, Purple Martin, Downy Woodpecker, Hairy Woodpecker, House Wren, Carolina Wren, Red-bellied Woodpecker, Northern Flicker, Prothonotary Warbler, Red-breasted Nuthatch, Tree Swallow, Great Crested Flycatcher.

What hole size should a Ontario birdhouse have?

It depends on the bird: the 21 local box nesters use 15 different hole sizes. See the table for each species.

Sources

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.