BirdAnalyst
Species · Colorado · BBS 2025 Release · 1966–2024

Red-winged Blackbird Population Trend in Colorado

All statesGeneralists

Red-winged Blackbird in Colorado has declined: down 31% on the route-weighted index since 1970.

-31%Since 1970TrendPercent 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 →
155Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
56YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Red-winged Blackbird Trends in ColoradoNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Red-winged Blackbird in Colorado. See the full index history below.

Red-winged Blackbird Population Forecast in Colorado

If the recent trend holds, Red-winged Blackbird in Colorado is projected to stay roughly flat through 2029, near 20 (95% range 5.8–35). A 5-year backtest shows a typical error of ±9%, with 100% of held-out values landing inside the 95% band.

-9%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 →
20Projected 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 →
5.8–3595% 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 →
±9%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, Red-winged Blackbird in Colorado is projected to stay roughly flat through 2029, near 20 (95% range 5.8–35). A 5-year backtest shows a typical error of ±9%, with 100% of held-out values landing inside the 95% band.19682029
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 →
2025227.937
2026227.436
2027216.836
2028216.335
2029205.835

Red-winged Blackbird Survey Routes in Colorado

Routes recording Red-winged Blackbird in Colorado.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Yampa25920231969
Prospect Val25320001992
Alamosa17120241988
Falfa15120241971
Dolores12319871968
Castleton11820241988
Fort Morgan11820241996
Julesburg11220211998
Pagosa Spgs10319821968
Amherst8920241992
Doyleville8620241988
Buford8420241970
Sheridan Lak8220161995
Fruita8120071988
Hudson7220241988
Adams Co.7220221989
Powderhorn7120231994
Limon6320241992
Cortez 26220172009
Pleasant View6020212021
De Beque5920241992
Flagler5520241997
Ludlow5520161998
Kirk5420231992
Yellowjacket Pass5420241998

Red-winged Blackbird Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniaconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.