BirdAnalyst
Species · Arizona · BBS 2026 Release · 1966–2025

Pygmy Nuthatch Population Trend in Arizona

All statesForest birds

Pygmy Nuthatch in Arizona has surged: up 173% on the route-weighted index since 1970.

+173%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 →
21Routes 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 Pygmy Nuthatch Trends in ArizonaNotable 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 →

Pygmy Nuthatch has surged in Arizona: up 173% on the route-weighted index since 1970.

Pygmy Nuthatch Population Forecast in Arizona

If the recent trend holds, Pygmy Nuthatch in Arizona is projected to fall about 51% by 2030 — from 8.4 in 2025 to a central estimate of 4.1 (95% range 0.97–7.3). A 5-year backtest shows a typical error of ±35.7%, with 80% of held-out values landing inside the 95% band.

-51%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 →
4.1Projected 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 →
0.97–7.395% 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 →
±35.7%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 Arizona is projected to fall about 51% by 2030 — from 8.4 in 2025 to a central estimate of 4.1 (95% range 0.97–7.3). A 5-year backtest shows a typical error of ±35.7%, with 80% 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 →
20264.00.877.2
20274.10.907.2
20284.10.927.3
20294.10.957.3
20304.10.977.3

Pygmy Nuthatch Survey Routes in Arizona

Routes recording Pygmy Nuthatch in Arizona.
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 →
Flagstaff10420251988
Happy Jack5920251977
Sprucedale5420251992
Tonto Vill.4120251992
Alpine3520251992
Pinetop2920221993
Mormon Lake2819751968
Sawmill2520141988
Tsaile2220231996
Zeniff1419841969
Mt. Graham1420251995
Williams1120251993
Forest Lakes920251992
Blue619911974
Dry Park620251992
Portal520251975
Aztec Peak519781974
Prescott320251974
Maine220251992
Rucker120072006
Carr Mtn120251999

Pygmy Nuthatch Population Trend in Other States

californiacoloradoidahomontananebraskanew-mexicooregonsouth-dakotautahwashingtonwyoming

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