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

White-crowned Sparrow Population Trend in Colorado

All statesGeneralists

White-crowned Sparrow in Colorado has surged: up 440% on the route-weighted index since 1970.

+440%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 →
55YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable White-crowned Sparrow 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 →

White-crowned Sparrow has surged in Colorado: up 440% on the route-weighted index since 1970.

White-crowned Sparrow Population Forecast in Colorado

If the recent trend holds, White-crowned Sparrow in Colorado is projected to rise about 45% by 2029 — from 3.9 in 2024 to a central estimate of 5.7 (95% range 3.1–8.2). A 5-year backtest shows a typical error of ±68.7%, with 60% of held-out values landing inside the 95% band.

+45%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 →
5.7Projected 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 →
3.1–8.295% 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 →
±68.7%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, White-crowned Sparrow in Colorado is projected to rise about 45% by 2029 — from 3.9 in 2024 to a central estimate of 5.7 (95% range 3.1–8.2). A 5-year backtest shows a typical error of ±68.7%, with 60% 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 →
20255.32.87.9
20265.42.98.0
20275.53.08.1
20285.63.18.1
20295.73.18.2

White-crowned Sparrow Survey Routes in Colorado

Routes recording White-crowned Sparrow 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 →
Stillwater Pass 26320242010
Buffalo Park3820231992
Stillwater Pass3520091998
Steamboat L.3420241996
Ragged Mtn.3420191994
Willow Peak3220211988
Lake City3120031988
Castleton2920241988
Yampa2620231969
Weston Pass 22620242001
Red Cliff2620241989
Mount Evans2220241996
Dunckley Pas2220241992
Heeney2120192017
Tincup2020241992
Walden1920241991
Lost Lake1920241993
Weston Pass1920001994
Como1620241994
Uncompahgre1520241988
Trail Ridge Road1420142003
Flattops1220191992
Lizard Head Pass1220242001
Groundhog Rs1120241992
Westcliffe1019981998

White-crowned Sparrow Population Trend in Other States

alaskacaliforniaidahomontananevadanew-mexicooregonutahwashingtonwyoming

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