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

Pygmy Nuthatch Population Trend in Colorado

All statesForest birds

Pygmy Nuthatch in Colorado has declined: down 27% on the route-weighted index since 1971.

-27%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 →
42Routes 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 Pygmy Nuthatch 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 Pygmy Nuthatch in Colorado. See the full index history below.

Pygmy Nuthatch Population Forecast in Colorado

If the recent trend holds, Pygmy Nuthatch in Colorado is projected to fall about 17% by 2029 — from 0.76 in 2024 to a central estimate of 0.64 (95% range 0.09–1.2). A 5-year backtest shows a typical error of ±29.7%, with 100% of held-out values landing inside the 95% band.

-17%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 →
0.64Projected 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 →
0.09–1.295% 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 →
±29.7%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, Pygmy Nuthatch in Colorado is projected to fall about 17% by 2029 — from 0.76 in 2024 to a central estimate of 0.64 (95% range 0.09–1.2). A 5-year backtest shows a typical error of ±29.7%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20250.620.081.2
20260.620.081.2
20270.630.091.2
20280.630.091.2
20290.640.091.2

Pygmy Nuthatch Survey Routes in Colorado

Routes recording Pygmy Nuthatch 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 →
Gold Hill2320121999
Elbert2020241998
Deadman Rd.1820241994
Cheesman Lk1320221969
Cortez1220052001
Gribbles Prk820241999
Guffey620241991
Gold Hill 2520242018
Comanche Pk420241995
Marshall Pas420121995
Nucla420242000
Moon Pass420112000
Ludlow420161998
Colona320072006
Dolores Riv319951988
Stillwater Pass320051999
Piedra220241993
Fox Creek220241993
Cokedale220221995
Kiowa 2220242023
Gardner220221999
Blackhead Pk220211991
Douglas Pass120152015
Trail Ridge Road120132013
Kiowa119991976

Pygmy Nuthatch Population Trend in Other States

arizonacaliforniaidahomontananebraskanew-mexicooregonsouth-dakotautahwashingtonwyoming

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