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

Yellow-eyed Junco Population Trend in Arizona

All statesForest birds

Yellow-eyed Junco in Arizona has surged: up 269% on the route-weighted index since 1976.

+269%Since 1976TrendPercent 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 →
7Routes 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 →
44YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Yellow-eyed Junco 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 →

Yellow-eyed Junco has surged in Arizona: up 269% on the route-weighted index since 1976.

Yellow-eyed Junco Population Forecast in Arizona

If the recent trend holds, Yellow-eyed Junco in Arizona is projected to rise about 76% by 2030 — from 1.4 in 2025 to a central estimate of 2.5 (95% range 0.00–5.0). A 5-year backtest shows a typical error of ±320.3%, with 80% of held-out values landing inside the 95% band.

+76%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 →
2.5Projected 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 →
0.00–5.095% 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 →
±320.3%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, Yellow-eyed Junco in Arizona is projected to rise about 76% by 2030 — from 1.4 in 2025 to a central estimate of 2.5 (95% range 0.00–5.0). A 5-year backtest shows a typical error of ±320.3%, with 80% of held-out values landing inside the 95% band.19742030
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 →
20262.40.004.9
20272.40.004.9
20282.40.005.0
20292.50.005.0
20302.50.005.0

Yellow-eyed Junco Survey Routes in Arizona

Routes recording Yellow-eyed Junco 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 →
Mt. Graham4320251995
Portal1520251975
Sunizona419791979
Rucker420091993
Carr Mtn220142001
Sunizona 2120062006
Aztec Peak119741974

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