Idaho · Summer breeder

Tree Swallows in Idaho

When tree swallows are present in Idaho, when they nest, which native Idaho plants feed them, and how to host them in a USDA 3b–7b yard.

Swallows (Hirundinidae)Tree SwallowTachycineta bicolor

Status in Idaho: Summer breeder
Nesting window: May–June
Broods: 1 per season
Hardiness zones: USDA 3b–7b
Nest box: 1 1/2 in hole, 5 × 5 in floor, 5–10 ft

When to expect tree swallows in Idaho

Tree Swallows are summer residents in Idaho, arriving shortly before nesting begins in May and leaving after the young are independent. Through the season they feed on flies, mayflies and dragonflies.

Semi-arid sagebrush plains along the Snake River and forested mountains to the north and center.

Nesting in Idaho

Across Idaho, tree swallows typically nest from May–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.

Hot, dry summers in the Snake River Plain and cool mountain summers.

Have boxes cleaned and mounted before April — 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 Idaho plants that attract tree swallows

Of the regional native plants we track for Idaho, these 8 provide food or cover tree swallows use:

Tall goldenrod

Solidago altissima · Perennial

Insect-rich in fall and seed in winter.

Paper birch

Betula papyrifera · Tree

Catkin seed feeds redpolls and siskins all winter.

Chokecherry

Prunus virginiana · Shrub

Dark summer fruit and heavy caterpillar load.

Common hackberry

Celtis occidentalis · Tree

Sweet dry fruit on the branch all winter.

Ponderosa pine

Pinus ponderosa · Tree

Seeds and bark insects; pygmy nuthatch and woodpecker habitat.

Rabbitbrush

Ericameria nauseosa · Shrub

Late-season bloom supports insects; seed for sparrows.

Douglas fir

Pseudotsuga menziesii · Tree

Seed for crossbills, siskins and chickadees.

Willow (Bebb)

Salix bebbiana · Shrub

Early catkins draw insects for arriving warblers and hummingbirds.

Feeding tree swallows through the Idaho 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 Idaho'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 Idaho year-round?

No. Tree Swallows are summer breeders in Idaho and leave for the winter.

When do tree swallows nest in Idaho?

Nesting in Idaho typically runs May–June, with 1 per season. Clutches are 4–7 eggs, incubated for 11–20 days.

What native plants attract tree swallows in Idaho?

Tall goldenrod, Paper birch, Chokecherry, Common hackberry, Ponderosa pine, Rabbitbrush, Douglas fir, Willow (Bebb) are native plants in Idaho 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.

Other backyard birds in Idaho

Black-capped Chickadee Downy Woodpecker Hairy Woodpecker American Goldfinch White-breasted Nuthatch House Wren House Finch Mourning Dove American Robin Dark-eyed Junco Song Sparrow Chipping Sparrow Northern Flicker Pileated Woodpecker Red-breasted Nuthatch Brown Creeper Red-winged Blackbird Evening Grosbeak Pine Siskin Common Redpoll Gray Catbird Cedar Waxwing Barn Swallow Yellow-rumped Warbler Eastern Kingbird American Tree Sparrow House Sparrow European Starling Steller's Jay Woodhouse's Scrub-Jay Black-billed Magpie Canada Jay Mountain Chickadee Chestnut-backed Chickadee Bushtit Juniper Titmouse Pygmy Nuthatch Black-chinned Hummingbird Rufous Hummingbird Broad-tailed Hummingbird Lesser Goldfinch Cassin's Finch Spotted Towhee California Quail Western Bluebird Mountain Bluebird Say's Phoebe White-crowned Sparrow Fox Sparrow Varied Thrush Violet-green Swallow Black-headed Grosbeak Lazuli Bunting Bullock's Oriole Eurasian Collared-Dove

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.