BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Brewer's Blackbird

IcteridaeGeneralistsEuphagus cyanocephalus

Brewer's Blackbird has surged: up 93% on the route-weighted index since 1968.

+93%Since 1968TrendPercent 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 →
1,407RoutesSurvey 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 Brewer's Blackbird

The Brewer's Blackbird (Euphagus cyanocephalus) is a North American member of the Blackbirds & Orioles (Icteridae). In this analysis it is grouped with the generalists.

Size
6.5–17 in long (16–43 cm) — a small to medium songbird (typical for the family)
Habitat
A broad range of open and wooded habitats, often near people.
Diet
An opportunistic mix of insects, seeds, fruit and scraps.
Range
Recorded on 1,407 Breeding Bird Survey routes across 20 states, most concentrated in the Great Basin.
Family
Icteridae · Generalists

Notable Brewer's Blackbird 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 →

Brewer's Blackbird has surged in surveyed states: up 93% on the route-weighted index since 1968.

Brewer's Blackbird Population Forecast

If the recent trend holds, Brewer's Blackbird is projected to stay roughly flat through 2029, near 4.3 (95% range 0.02–8.6). A 5-year backtest shows a typical error of ±33.4%, with 100% of held-out values landing inside the 95% band.

+1%Change by 2029TrendPercent 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 →
4.3Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.02–8.695% 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 →
±33.4%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, Brewer's Blackbird is projected to stay roughly flat through 2029, near 4.3 (95% range 0.02–8.6). A 5-year backtest shows a typical error of ±33.4%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20254.60.298.9
20264.50.228.8
20274.50.158.8
20284.40.098.7
20294.30.028.6

Where the Brewer's Blackbird Is Detected

BBS routes recording Brewer's Blackbird, sized by most recent count.

Brewer's Blackbird Population Trend by State

Brewer's Blackbird 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-61%197024
California-70%1970233
Colorado-55%1970142
Idaho-80%197057
Indianainsufficient datan/a2
Michigan-85%196943
Minnesota-69%196972
Montana-55%1970108
Nebraska+122%198110
Nevada-12%197045
New Mexico-26%197033
North Dakota+207%196951
Oklahoma+30%19727
Oregon-56%1970129
South Dakota+308%196946
Texasinsufficient datan/a5
Utah-57%197094
Washington-42%197095
Wisconsin-84%196877
Wyoming-52%1970134

Brewer's Blackbird Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Brewer's Blackbird 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-73%197097
Great Basin-28%1970247
Northern Rockies-62%1970204
Prairie Potholes+118%196993
Boreal Hardwood Transition-78%196898
Sierra Nevada-55%197037
Southern Rockies / Colorado Plateau-33%1970192
Badlands and Prairies+24%1969131
Shortgrass Prairie-88%197061
Eastern Tallgrass Prairie-78%19715
Prairie Hardwood Transition-79%196865
Coastal California-77%1970118
Sonoran and Mojave Deserts-97%197032
Sierra Madre Occidental-76%197011
Chihuahuan Desert-61%19748

Brewer's Blackbird Conservation Status

Our route-weighted index shows it up about 93% since 1968.

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.