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Species · Colorado · BBS 2025 Release · 1966–2024

Clark's Nutcracker Population Trend in Colorado

All statesGeneralists

Clark's Nutcracker in Colorado has surged: up 20× on the route-weighted index since 1971.

20×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 →
53YearsYears 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 20× 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 fall about 22% by 2029 — from 2.6 in 2024 to a central estimate of 2.1 (95% range 1.1–3.0). A 5-year backtest shows a typical error of ±60.3%, with 60% of held-out values landing inside the 95% band.

-22%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 →
2.1Projected 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 →
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 →
±60.3%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 fall about 22% by 2029 — from 2.6 in 2024 to a central estimate of 2.1 (95% range 1.1–3.0). A 5-year backtest shows a typical error of ±60.3%, 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 →
20251.90.992.9
20262.01.02.9
20272.01.12.9
20282.01.13.0
20292.11.13.0

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 →
Piceance Basin3820042003
Moon Pass3720241998
South Fork3120241996
Mount Evans1920241996
Pinos Creek1819901988
Summitville1620241992
Fox Creek1620241993
Flattops1520171994
Nucla1520242000
Haycamp Mesa1520241998
Deadman Rd.1420241992
Dinosaur1420191995
Cochetopa Pass1420241998
Guffey1220241990
Gribbles Prk1220241995
Owl Creek Pass1120241999
Pinon920221992
Guanella Pas820241992
Trail Ridge Road720142003
Willow Peak620181988
Wet Mtns.620241993
Baxter Pass620241994
Como620241994
Marshall Pas620191995
Blackhead Pk519981996

Clark's Nutcracker Population Trend in Other States

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