When do Bullock's orioles arrive in Colorado?
The Bullock's Oriole is a summer breeder in Colorado — here is when to expect it, when it leaves, and how to be ready.
Bullock's Oriole timing in Colorado
- Arrives
- Around April
- Leaves
- By August
- Status here
- Summer breeder
- Nesting season
- May–July
- Present roughly
- April–August
In Colorado, Bullock's orioles are present through the warm months, arriving around April 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 Bullock's orioles 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 April is the time to act. Have feeders cleaned, filled and out by early April — the first Bullock's orioles into Colorado are scouting for reliable food, and a station that's ready early gets added to their route.
Once nesting begins around May, adults switch to protein-rich food for their young and visits to feeders become quick and purposeful. Expect the busiest activity at dawn.
What Bullock's orioles eat while they're here
- Caterpillars
Weaves hanging nests in cottonwoods along western rivers.
Full Bullock's Oriole diet guide → · Best feeder for Bullock's orioles →
Native plants that hold Bullock's orioles in Colorado
Food keeps a migrant for a day; habitat keeps it for the season. These Colorado-native plants are known to attract Bullock's orioles:
Red fruit heads hang on through winter.
Blue fruit on red stems in early fall.
Scarlet late-summer spikes; a hummingbird magnet in moist soil.
Tubular flowers for hummingbirds and seed heads for finches.
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 Bullock's orioles arrive in Colorado?
Bullock's orioles typically arrive in Colorado around April, with nesting underway by May. Timing can shift a week or two with the weather in any given year.
When do Bullock's orioles leave Colorado?
Most Bullock's orioles have left Colorado by August. They spend the winter farther south and return the following spring.
Do Bullock's orioles stay in Colorado all year?
No — in Colorado the Bullock's Oriole is a summer breeder, present roughly April–August. Outside that window it is rarely seen in the state.
What should I put out before Bullock's orioles arrive in Colorado?
Have feeders up and clean by early April — first arrivals scout reliable food sources. Good offerings for this species: caterpillars.
Sources
- Bullock's Oriole — All About Birds, Cornell Lab of Ornithology
- Bullock's Oriole life history — Cornell Lab of Ornithology
- Bullock's Oriole — Audubon Guide to North American Birds
- 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.