Nest boxes · Colorado

Birdhouses for Colorado

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

Local conditions

Growing zones: USDA 3a–7b
Winter: Cold snaps alternate with sunny, dry thaws; heated baths are valuable because natural water freezes nightly.
Summer: Warm, dry days and cool nights; afternoon storms are common in July and August.
Box nesters: 21 (16 year-round residents)
Hole sizes needed: 10 distinct

Semi-arid high plains in the east and the Rocky Mountains through the center, with most backyards between 5,000 and 7,000 ft.

Box calendar for Colorado

Bird	Status	Hole	Height	Up by	Nesting	Clean out
Eastern Screech-Owl	Year-round resident	3 in	10–30 ft	February	March–May	June
Bewick's Wren	Year-round resident	1 1/4 in	5–10 ft	February	March–June	July
American Kestrel	Year-round resident	3 in	10–30 ft	February	March–June	July
Western Screech-Owl	Year-round resident	3 in	10–30 ft	February	March–June	July
Northern Saw-whet Owl	Year-round resident	2 1/2 in	10–20 ft	February	March–June	July
Black-capped Chickadee	Year-round resident	1 1/8 in round	5–15 ft	March	April–July	August
Downy Woodpecker	Year-round resident	1 1/4 in round	5–20 ft, box packed with wood shavings	March	April–June	July
Hairy Woodpecker	Year-round resident	1 1/2 in round	8–20 ft, box packed with wood shavings	March	April–June	July
White-breasted Nuthatch	Year-round resident	1 1/4 in round	5–20 ft	March	April–June	July
Northern Flicker	Year-round resident	2 1/2 in	6–20 ft	March	April–June	July
Juniper Titmouse	Year-round resident	1 1/4 in	5–15 ft	March	April–June	July
Western Bluebird	Summer breeder	1 1/2 in	5–10 ft	March	April–July	August
Ash-throated Flycatcher	Summer breeder	1 1/2 in	5–20 ft	March	April–July	August
House Wren	Summer breeder	1 to 1 1/8 in round	5–10 ft near shrubs	April	May–August	September
Red-breasted Nuthatch	Year-round resident	1 1/4 in	5–15 ft	April	May–June	July
Tree Swallow	Summer breeder	1 1/2 in	5–10 ft	April	May–June	July
Mountain Chickadee	Year-round resident	1 1/8 in	5–15 ft	April	May–July	August
Pygmy Nuthatch	Year-round resident	1 1/4 in	8–20 ft	April	May–June	July
Mountain Bluebird	Year-round resident	1 9/16 in	5–10 ft	April	May–July	August
Violet-green Swallow	Summer breeder	1 1/2 in	8–15 ft	April	May–July	August
Lewis's Woodpecker	Year-round resident	2 1/2 in	12–20 ft	April	May–July	August

Nesting windows are shifted from each species' mid-latitude season by Colorado'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 Colorado?

By February for the earliest local nester, the Eastern Screech-Owl, which starts nesting around March.

Which birds use nest boxes in Colorado?

Eastern Screech-Owl, Bewick's Wren, American Kestrel, Western Screech-Owl, Northern Saw-whet Owl, Black-capped Chickadee, Downy Woodpecker, Hairy Woodpecker, White-breasted Nuthatch, Northern Flicker, Juniper Titmouse, Western Bluebird, Ash-throated Flycatcher, House Wren, Red-breasted Nuthatch, Tree Swallow, Mountain Chickadee, Pygmy Nuthatch, Mountain Bluebird, Violet-green Swallow, Lewis's Woodpecker.

What hole size should a Colorado birdhouse have?

It depends on the bird: the 21 local box nesters use 10 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.