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

Wilson's Warbler Population Trend in Colorado

All statesForest birds

Wilson's Warbler in Colorado has edged down: down 23% on the route-weighted index since 1970.

-23%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 →
73Routes 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 Wilson's Warbler 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 Wilson's Warbler in Colorado. See the full index history below.

Wilson's Warbler Population Forecast in Colorado

If the recent trend holds, Wilson's Warbler in Colorado is projected to rise about 111% by 2030 — from 0.72 in 2025 to a central estimate of 1.5 (95% range 0.64–2.4). A 5-year backtest shows a typical error of ±70.8%, with 80% of held-out values landing inside the 95% band.

+111%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 →
1.5Projected 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 →
0.64–2.495% 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 →
±70.8%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, Wilson's Warbler in Colorado is projected to rise about 111% by 2030 — from 0.72 in 2025 to a central estimate of 1.5 (95% range 0.64–2.4). A 5-year backtest shows a typical error of ±70.8%, with 80% 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 →
20261.50.592.4
20271.50.602.4
20281.50.612.4
20291.50.632.4
20301.50.642.4

Wilson's Warbler Survey Routes in Colorado

Routes recording Wilson's Warbler 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 →
Tincup3520251992
Weston Pass1120001995
Marshall Pas1120141995
Guanella Pas1120251992
Lost Lake1020251990
Comanche Pk720241994
Blackhead Pk720211991
Stillwater Pass620071998
Cortez620051993
Mount Evans520141998
Rifle Falls520131998
Yampa420231972
Parlin420251968
Buffalo Park420231993
Pinon420041995
Colona319811972
Red Cliff320251989
Ragged Mtn.320191994
Wet Mtns.319971997
Groundhog Rs320251992
Gardner320082001
Nucla320061999
Lizard Head Pass320242001
Last Chance220001989
Summitville220251991

Wilson's Warbler Population Trend in Other States

alaskacaliforniaidahomainemichiganminnesotamontananevadanew-hampshirenew-mexiconew-yorkoregonutahvermontwashingtonwisconsinwyoming

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