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Species · Arizona · BBS 2025 Release · 1966–2024

Clark's Nutcracker Population Trend in Arizona

All statesGeneralists

Clark's Nutcracker in Arizona has held roughly steady: down 4% on the route-weighted index since 1974.

-4%Since 1974TrendPercent 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 →
14Routes 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 →
49YearsYears 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 ArizonaNotable 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 Clark's Nutcracker in Arizona. See the full index history below.

Clark's Nutcracker Population Forecast in Arizona

If the recent trend holds, Clark's Nutcracker in Arizona is projected to stay roughly flat through 2029, near 0.09 (95% range 0.00–0.40). A 5-year backtest shows a typical error of ±129.5%, 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 →
0.09Projected 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 →
0.00–0.4095% 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 →
±129.5%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 Arizona is projected to stay roughly flat through 2029, near 0.09 (95% range 0.00–0.40). A 5-year backtest shows a typical error of ±129.5%, 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 →
20250.100.000.41
20260.100.000.41
20270.100.000.41
20280.090.000.41
20290.090.000.40

Clark's Nutcracker Survey Routes in Arizona

Routes recording Clark's Nutcracker 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 →
Maine719941993
Blue619911974
Portal519971997
Sprucedale520211992
Williams320012001
Round Rock219701970
Sawmill220101988
House Rock120182008
Forest Lakes119951995
Flagstaff120211988
Alpine120231992
Tsaile120231995
Mormon Lake119691969
Dry Park120241992

Clark's Nutcracker Population Trend in Other States

californiacoloradoidahomontananevadanew-mexicooregonsouth-dakotautahwashingtonwyoming

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