When do western bluebirds arrive in Colorado?
The Western Bluebird is a summer breeder in Colorado — here is when to expect it, when it leaves, and how to be ready.
Western Bluebird timing in Colorado
- Arrives
- Around March
- Leaves
- By August
- Status here
- Summer breeder
- Nesting season
- April–July
- Present roughly
- March–August
In Colorado, western bluebirds are present through the warm months, arriving around March and heading south again by August.
These windows are set by latitude: Colorado sits in the middle part of this species' range, so timing here tracks the continental average closely. In any given year, weather can move the first arrivals by a week or two either way.
Month by month in this state
Highlighted months are when western bluebirds are expected in Colorado. The edges of the window are the interesting weeks — first arrivals and last departures vary most from year to year.
Getting ready before they arrive
The week before March is the time to act. Have feeders cleaned, filled and out by early March — the first western bluebirds into Colorado are scouting for reliable food, and a station that's ready early gets added to their route.
Western bluebirds nest in cavities, so boxes need to be up and cleaned before arrival — a box mounted after they've claimed territories will usually sit empty until next year. Western Bluebird nest box dimensions and mounting →
Once nesting begins around April, adults switch to protein-rich food for their young and visits to feeders become quick and purposeful. Expect the busiest activity at dawn.
What western bluebirds eat while they're here
- Beetles and grasshoppers
Uses 1 1/2 in nest boxes in open oak and pine woodland; boxes have helped recovery in the Pacific Northwest.
Full Western Bluebird diet guide → · Best feeder for western bluebirds →
Native plants that hold western bluebirds in Colorado
Food keeps a migrant for a day; habitat keeps it for the season. These Colorado-native plants are known to attract western bluebirds:
Red fruit heads hang on through winter.
Blue fruit on red stems in early fall.
Late nectar for insects and fall seed for sparrows.
Insect-rich in fall and seed in winter.
Fast-growing northern cherry with midsummer fruit.
Dark summer fruit and heavy caterpillar load.
White fruit and red winter stems; good thicket cover.
Berry-like cones feed bluebirds, solitaires and waxwings in winter.
Keep exploring
Frequently asked
When do western bluebirds arrive in Colorado?
western bluebirds typically arrive in Colorado around March, with nesting underway by April. Timing can shift a week or two with the weather in any given year.
When do western bluebirds leave Colorado?
Most western bluebirds have left Colorado by August. They spend the winter farther south and return the following spring.
Do western bluebirds stay in Colorado all year?
No — in Colorado the Western Bluebird is a summer breeder, present roughly March–August. Outside that window it is rarely seen in the state.
What should I put out before western bluebirds arrive in Colorado?
Have feeders up and clean by early March — first arrivals scout reliable food sources. Good offerings for this species: beetles and grasshoppers.
Sources
- Western Bluebird — All About Birds, Cornell Lab of Ornithology
- Western Bluebird life history — Cornell Lab of Ornithology
- Western Bluebird — Audubon Guide to North American Birds
- NestWatch nest box plans and species requirements — Cornell Lab
- eBird region overview and bar charts — Colorado
- USDA Plant Hardiness Zone Map (2023)
- Audubon Native Plants Database
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.