BirdAnalyst
Species · Colorado · BBS 2026 Release · 1966–2025

Swainson's Hawk Population Trend in Colorado

All statesBirds of prey

Swainson's Hawk in Colorado has increased: up 47% on the route-weighted index since 1970.

+47%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 →
103Routes 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 →
57YearsYears 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 rise about 40% by 2030 — from 1.5 in 2025 to a central estimate of 2.1 (95% range 0.98–3.2). A 5-year backtest shows a typical error of ±27.1%, with 100% of held-out values landing inside the 95% band.

+40%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 →
2.1Projected 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 →
0.98–3.295% 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 →
±27.1%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 rise about 40% by 2030 — from 1.5 in 2025 to a central estimate of 2.1 (95% range 0.98–3.2). A 5-year backtest shows a typical error of ±27.1%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20262.10.953.2
20272.10.963.2
20282.10.973.2
20292.10.973.2
20302.10.983.2

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 →
Gilpin1520251970
Stoneham1420251992
Moffat1320251970
Haswell1220241992
Neegrande1220251992
Pritchett1020251995
Crowley820241989
Rockport820241994
Briggsdale720251968
Hudson720251988
Mosca720251992
Timpas720251995
Lamar620241973
Wildhorse L620251988
Adams Co.620221989
Cheyenne620251990
Sheridan Lak620161995
Arsenal620151991
Kirk520231992
Rush420241983
Boyero420171979
Prospect Val420001992
Bennett420251995
Flagler420251997
Prospect Valley 2420252002

Swainson's Hawk Population Trend in Other States

alaskaarizonaarkansascaliforniaidahoillinoisiowakansaslouisianaminnesotamissourimontananebraskanevadanew-mexiconorth-dakotaoklahomaoregonsouth-dakotatexasutahwashingtonwisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.