Colorado · Year-round resident

Brown-headed Cowbirds in Colorado

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

Blackbirds (Icteridae)Brown-headed CowbirdMolothrus ater

Status in Colorado: Year-round resident
Nesting window: April–July
Broods: —
Hardiness zones: USDA 3a–7b

When to expect cowbirds in Colorado

Brown-headed Cowbirds live in Colorado all year. Cold snaps alternate with sunny, dry thaws; heated baths are valuable because natural water freezes nightly. That makes the cold months the time your yard matters most to them.

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

Nesting in Colorado

Across Colorado, cowbirds typically nest from April–July. Plan around that window: March for setup, July for clean-out.

Warm, dry days and cool nights; afternoon storms are common in July and August.

Brown-headed Cowbirds don't use nest boxes. Keep dense native shrubs and trees such as rabbitbrush for nest sites.
Delay heavy pruning of shrubs until after July.

Native Colorado plants that attract cowbirds

Of the regional native plants we track for Colorado, these 8 provide food or cover cowbirds use:

Wild bergamot

Monarda fistulosa · Perennial

Tubular flowers for hummingbirds and seed heads for finches.

Black-eyed Susan

Rudbeckia hirta · Perennial

Prolific seed heads for finches and sparrows.

Common sunflower

Helianthus annuus · Perennial

Annual native sunflower — the original feeder seed.

New England aster

Symphyotrichum novae-angliae · Perennial

Late nectar for insects and fall seed for sparrows.

Little bluestem

Schizachyrium scoparium · Perennial

Native bunchgrass; winter seed and ground cover for sparrows and juncos.

Tall goldenrod

Solidago altissima · Perennial

Insect-rich in fall and seed in winter.

Rocky Mountain bee plant

Cleome serrulata · Perennial

Nectar-rich in summer, seed for finches in fall.

Rabbitbrush

Ericameria nauseosa · Shrub

Late-season bloom supports insects; seed for sparrows.

Feeding cowbirds through the Colorado year

Top foods: Millet, Cracked corn.
In Colorado's winter: Cold snaps alternate with sunny, dry thaws; heated baths are valuable because natural water freezes nightly.

Full diet breakdown for cowbirds · Best feeder for cowbirds

Frequently asked

Are cowbirds in Colorado year-round?

Yes. Brown-headed Cowbirds are year-round residents in Colorado.

When do cowbirds nest in Colorado?

Nesting in Colorado typically runs April–July, with —. Clutches are up to 36 eggs per season, one per host nest, incubated for 10–12 days.

What native plants attract cowbirds in Colorado?

Wild bergamot, Black-eyed Susan, Common sunflower, New England aster, Little bluestem, Tall goldenrod, Rocky Mountain bee plant, Rabbitbrush are native plants in Colorado that provide food or cover for cowbirds.

Other backyard birds in Colorado

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 Red-breasted Nuthatch Brown Creeper Common Grackle Red-winged Blackbird Evening Grosbeak Pine Siskin Indigo Bunting Gray Catbird Northern Mockingbird Brown Thrasher Cedar Waxwing Tree Swallow Barn Swallow Yellow-rumped Warbler Eastern Screech-Owl Eastern Kingbird American Tree Sparrow House Sparrow European Starling Steller's Jay Woodhouse's Scrub-Jay Black-billed Magpie Canada Jay Mountain Chickadee Bushtit Juniper Titmouse Pygmy Nuthatch Black-chinned Hummingbird Broad-tailed Hummingbird Lesser Goldfinch Cassin's Finch Spotted Towhee Canyon Towhee Gambel's Quail Western Bluebird Mountain Bluebird Say's Phoebe Ladder-backed Woodpecker Curve-billed Thrasher Bewick's Wren White-crowned Sparrow Fox Sparrow Violet-green Swallow Black-headed Grosbeak Lazuli Bunting Bullock's Oriole Eurasian Collared-Dove American Crow Common Raven Cooper's Hawk Sharp-shinned Hawk Red-tailed Hawk Great Horned Owl American Kestrel Wild Turkey Mallard Great Blue Heron Belted Kingfisher Ruby-crowned Kinglet Golden-crowned Kinglet Hermit Thrush Pine Grosbeak Red Crossbill Gray Catbird Western Tanager Black-throated Sparrow Lark Sparrow Green-tailed Towhee Pinyon Jay Clark's Nutcracker Western Screech-Owl Hooded Merganser Band-tailed Pigeon Yellow Warbler Common Yellowthroat American Redstart Yellow-breasted Chat Orange-crowned Warbler Red-eyed Vireo Warbling Vireo Least Flycatcher Western Kingbird Scissor-tailed Flycatcher Ash-throated Flycatcher Cliff Swallow Northern Rough-winged Swallow Bank Swallow Common Nighthawk Canada Goose American Coot Killdeer Spotted Sandpiper Black-crowned Night Heron Turkey Vulture Osprey Bald Eagle Merlin Peregrine Falcon Northern Saw-whet Owl Burrowing Owl Lewis's Woodpecker Black-backed Woodpecker American Three-toed Woodpecker Savannah Sparrow Vesper Sparrow Snow Bunting Lapland Longspur Horned Lark White-winged Crossbill Gray-crowned Rosy-Finch Bohemian Waxwing Greater Roadrunner Bobolink Yellow-headed Blackbird Brewer's Blackbird Great-tailed Grackle Rock Pigeon

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.