BirdAnalyst
Species · BBS 2026 Release · 1966–2025

Bullock's Oriole Population Analysis

IcteridaeForest birdsIcterus bullockii

Bullock's Oriole has surged: up 186% on the route-weighted index since 1969.

+186%Since 1969TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
1,210RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
58Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

About the Bullock's Oriole

The Bullock's Oriole (Icterus bullockii) is a North American member of the Blackbirds & Orioles (Icteridae). In this analysis it is grouped with the forest birds.

Size
6.5–17 in long (16–43 cm) — a small to medium songbird (typical for the family)
Habitat
Woodlands and forest edges, including wooded suburbs and parks.
Diet
Insects and spiders gleaned from foliage and bark, with seeds and berries in season.
Range
Recorded on 1,210 Breeding Bird Survey routes across 17 states, most concentrated in the Great Basin.
Family
Icteridae · Forest birds

Notable Bullock's Oriole TrendsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Bullock's Oriole has surged in surveyed states: up 186% on the route-weighted index since 1969.

Bullock's Oriole Population Forecast

If the recent trend holds, Bullock's Oriole is projected to stay roughly flat through 2030, near 0.73 (95% range 0.38–1.1). A 5-year backtest shows a typical error of ±19.3%, with 100% of held-out values landing inside the 95% band.

-6%Change by 2030TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
0.73Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.38–1.195% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±19.3%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Bullock's Oriole is projected to stay roughly flat through 2030, near 0.73 (95% range 0.38–1.1). A 5-year backtest shows a typical error of ±19.3%, with 100% of held-out values landing inside the 95% band.19672030
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20260.730.391.1
20270.730.381.1
20280.730.381.1
20290.730.381.1
20300.730.381.1

Where the Bullock's Oriole Is Detected

BBS routes recording Bullock's Oriole, sized by most recent count.

Bullock's Oriole Population Trend by State

Bullock's Oriole population trend by state.
TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Arizona+208%197066
California-38%1970220
Colorado+140%1970121
Idaho+64%197048
Kansas-45%197114
Montana+50%197081
Nebraska+44%197318
Nevada+44%197043
New Mexico+101%197076
North Dakota+36%198710
Oklahoma-8%196921
Oregon+12%197090
South Dakota+741%197023
Texas+2%1969144
Utah+297%197071
Washington+5%197082
Wyoming+33%197082

Bullock's Oriole Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Bullock's Oriole population trend by Bird Conservation Region.
TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Northern Pacific Rainforest-52%197072
Great Basin+31%1970212
Northern Rockies+39%1970134
Prairie Potholes+111%198314
Sierra Nevada-59%197125
Southern Rockies / Colorado Plateau+111%1970151
Badlands and Prairies+490%196996
Shortgrass Prairie+92%1969128
Central Mixed Grass Prairie-23%196954
Edwards Plateau-76%197613
Oaks and Prairies+21%196923
Coastal California-33%1970113
Sonoran and Mojave Deserts-33%197067
Sierra Madre Occidental+96%197130
Chihuahuan Desert+432%197046
Tamaulipan Brushlands+44%196926
Gulf Coastal Prairie+93%20026

Bullock's Oriole Conservation Status

Our route-weighted index shows it up about 186% since 1969.

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14. Trend is a route-weighted relative-abundance index, not an absolute population.