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Species · Colorado · BBS 2026 Release · 1966–2025

Clark's Nutcracker Population Trend in Colorado

All statesForest birds

Clark's Nutcracker in Colorado has surged: up 21× on the route-weighted index since 1971.

21×Since 1971TrendPercent 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 →
77Routes 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 →
54YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Clark's Nutcracker 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 →

Clark's Nutcracker has surged in Colorado: up 21× on the route-weighted index since 1971.

Clark's Nutcracker Population Forecast in Colorado

If the recent trend holds, Clark's Nutcracker in Colorado is projected to rise about 25% by 2030 — from 1.7 in 2025 to a central estimate of 2.1 (95% range 1.1–3.0). A 5-year backtest shows a typical error of ±48.9%, with 100% of held-out values landing inside the 95% band.

+25%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 →
1.1–3.095% 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 →
±48.9%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, Clark's Nutcracker in Colorado is projected to rise about 25% by 2030 — from 1.7 in 2025 to a central estimate of 2.1 (95% range 1.1–3.0). A 5-year backtest shows a typical error of ±48.9%, 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 →
20261.91.02.9
20272.01.02.9
20282.01.12.9
20292.01.13.0
20302.11.13.0

Clark's Nutcracker Survey Routes in Colorado

Routes recording Clark's Nutcracker 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 →
Gribbles Prk4820251995
Piceance Basin3820042003
Moon Pass1920251998
Mount Evans1920241996
Pinos Creek1819901988
Guffey1520251990
Nucla1520242000
Dinosaur1420191995
Fox Creek1120251993
Owl Creek Pass1120241999
Guanella Pas820241992
Como820251994
Powderhorn820252003
South Fork820251996
Trail Ridge Road720142003
Summitville620251992
Baxter Pass620241994
Marshall Pas620191995
Blackhead Pk519981996
Wet Mtns.520251993
Rollins Pass520251998
Black Sulphur Cr520222015
Colona420121972
Red Cliff420251998
Colona 2420162015

Clark's Nutcracker Population Trend in Other States

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