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

American Goshawk Population Trend in Colorado

All statesGeneralists

American Goshawk in Colorado has fallen sharply: down 60% on the route-weighted index since 1983.

-60%Since 1983TrendPercent 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 →
36Routes 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 →
31YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable American Goshawk 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 declinecomputed 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 →

American Goshawk has fallen sharply in Colorado: down 60% on the route-weighted index since 1983.

American Goshawk Population Forecast in Colorado

If the recent trend holds, American Goshawk in Colorado is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.04). A 5-year backtest shows a typical error of ±34.7%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.01Projected 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 →
0.00–0.0495% 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 →
±34.7%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, American Goshawk in Colorado is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.04). A 5-year backtest shows a typical error of ±34.7%, with 100% of held-out values landing inside the 95% band.19722029
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 →
20250.010.000.04
20260.010.000.04
20270.010.000.04
20280.010.000.04
20290.010.000.04

American Goshawk Survey Routes in Colorado

Routes recording American Goshawk 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 →
Tarryall220142008
Baxter Pass220132013
Yampa119721972
Mount Evans120121997
Mesaverde Np120002000
Aspen119971997
Parlin120151977
Falfa120212021
Rio Grnds Rs120062006
Weston Pass 2120182018
Wray Gulch120052005
Lost Lake120002000
Red Cliff120021999
Uncompahgre120062006
Castleton120131996
Guffey120171991
Comanche Pk120152006
Dolores Riv120002000
Ragged Mtn.120041994
Marshall Pas120121999
Gold Hill 2120212021
Buffalo Park120161995
Flattops120032003
Thomasville120022002
Guanella Pas120122012

American Goshawk Population Trend in Other States

alaskaarizonacaliforniaconnecticutidahomainemassachusettsmichiganminnesotamontananevadanew-hampshirenew-jerseynew-mexiconew-yorkoregonpennsylvaniarhode-islandsouth-dakotautahvermontwashingtonwisconsinwyoming

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