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Species · Montana · BBS 2025 Release · 1966–2024

Pygmy Nuthatch Population Trend in Montana

All statesForest birds

Pygmy Nuthatch in Montana has collapsed: down 78% on the route-weighted index since 1987.

-78%Since 1987TrendPercent 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 →
13Routes 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 →
31YearsYears 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 MontanaNotable 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 declinecomputed 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 →

Pygmy Nuthatch has collapsed in Montana: down 78% on the route-weighted index since 1987.

Pygmy Nuthatch Population Forecast in Montana

If the recent trend holds, Pygmy Nuthatch in Montana is projected to stay roughly flat through 2029, near 0.03 (95% range 0.00–0.25). A 5-year backtest shows a typical error of ±331.6%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.03Projected 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 →
0.00–0.2595% 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 →
±331.6%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 Montana is projected to stay roughly flat through 2029, near 0.03 (95% range 0.00–0.25). A 5-year backtest shows a typical error of ±331.6%, with 100% of held-out values landing inside the 95% band.19762029
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 →
20250.040.000.26
20260.040.000.26
20270.030.000.25
20280.030.000.25
20290.030.000.25

Pygmy Nuthatch Survey Routes in Montana

Routes recording Pygmy Nuthatch in Montana.
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 →
Kalispell320182010
Pablo Res.320072007
Skalkaho319971992
Arlee320131991
Ninemile220242004
Reed Point220132013
Painted Rock219971992
Libby Dam119901986
Sula120232023
Victor120191994
St Regis119971986
Woodman119761976
Clinton120232022

Pygmy Nuthatch Population Trend in Other States

arizonacaliforniacoloradoidahonebraskanew-mexicooregonsouth-dakotautahwashingtonwyoming

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