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

Red-tailed Hawk Population Trend in Colorado

All statesGeneralists

Red-tailed Hawk in Colorado has surged: up 372% on the route-weighted index since 1970.

+372%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 →
156Routes 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-tailed Hawk 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 →

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 →

Red-tailed Hawk has surged in Colorado: up 372% on the route-weighted index since 1970.

Red-tailed Hawk Population Forecast in Colorado

If the recent trend holds, Red-tailed Hawk in Colorado is projected to stay roughly flat through 2029, near 2.1 (95% range 1.6–2.6). A 5-year backtest shows a typical error of ±7.7%, with 100% of held-out values landing inside the 95% band.

+6%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 →
2.1Projected 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 →
1.6–2.695% 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 →
±7.7%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-tailed Hawk in Colorado is projected to stay roughly flat through 2029, near 2.1 (95% range 1.6–2.6). A 5-year backtest shows a typical error of ±7.7%, 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 →
20252.01.52.5
20262.11.62.6
20272.11.62.6
20282.11.62.6
20292.11.62.6

Red-tailed Hawk Survey Routes in Colorado

Routes recording Red-tailed Hawk 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 →
Arsenal 21720242016
Arsenal1220151991
Haswell920241992
Gilpin820241971
Adams Co.820221989
Last Chance720161978
Nunn720211996
Ludlow720161998
Crowley620241989
Trinchera620221990
Last Chance 2620242017
Stillwater Pass620091998
Elbert620241998
Harmony520241973
San Luis520241991
Weston Pass520001997
Basin520241995
Doyle Bridge 2520231998
Great Divide420241974
Buford420241970
Aspen420241979
Kiowa420181968
Guffey420241990
Kiowa 2420242019
Dunckley Pas420241997

Red-tailed Hawk 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.