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

Swainson's Hawk Population Trend in Colorado

All statesGeneralists

Swainson's Hawk in Colorado has increased: up 44% on the route-weighted index since 1970.

+44%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 →
102Routes 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 Swainson's 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 →

No notable trend signals for Swainson's Hawk in Colorado. See the full index history below.

Swainson's Hawk Population Forecast in Colorado

If the recent trend holds, Swainson's Hawk in Colorado is projected to stay roughly flat through 2029, near 2.1 (95% range 1.0–3.2). A 5-year backtest shows a typical error of ±18.3%, with 100% of held-out values landing inside the 95% band.

+10%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 →
1.0–3.295% 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 →
±18.3%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, Swainson's Hawk in Colorado is projected to stay roughly flat through 2029, near 2.1 (95% range 1.0–3.2). A 5-year backtest shows a typical error of ±18.3%, 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 →
20252.10.983.2
20262.10.993.2
20272.11.03.2
20282.11.03.2
20292.11.03.2

Swainson's Hawk Survey Routes in Colorado

Routes recording Swainson's 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 →
Moffat1520241970
Nunn1520211995
Edler1420241992
Haswell1220241992
Neegrande1220241992
Karval1220191995
Briggsdale1020241968
Hudson1020241988
Mesita920242005
Gilpin820241970
Crowley820241989
Last Chance 2820242017
Rockport820241994
Pritchett720241995
Lamar620241973
Adams Co.620221989
Edison620241988
Sheridan Lak620161995
Timpas620191995
Arsenal620151991
Kirk520231992
Prospect Valley 2520232002
Rush420241983
Boyero420171979
Willow Peak420211988

Swainson's Hawk Population Trend in Other States

arizonaarkansascaliforniaidahoillinoisiowakansaslouisianaminnesotamissourimontananebraskanevadanew-mexiconorth-dakotaoklahomaoregonsouth-dakotatexasutahwashingtonwisconsinwyoming

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