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

Yellow Warbler Population Trend in Arizona

All statesForest birds

Yellow Warbler in Arizona has surged: up 432% on the route-weighted index since 1970.

+432%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 →
45Routes 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 →
56YearsYears 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 Warbler 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 Warbler has surged in Arizona: up 431% on the route-weighted index since 1970.

Yellow Warbler Population Forecast in Arizona

If the recent trend holds, Yellow Warbler in Arizona is projected to stay roughly flat through 2030, near 1.1 (95% range 0.72–1.5). A 5-year backtest shows a typical error of ±22.3%, with 100% of held-out values landing inside the 95% band.

-1%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 →
1.1Projected 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 →
0.72–1.595% 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 →
±22.3%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 Warbler in Arizona is projected to stay roughly flat through 2030, near 1.1 (95% range 0.72–1.5). A 5-year backtest shows a typical error of ±22.3%, with 100% 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 →
20261.10.661.5
20271.10.681.5
20281.10.691.5
20291.10.711.5
20301.10.721.5

Yellow Warbler Survey Routes in Arizona

Routes recording Yellow Warbler 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 →
Cutter 23520182015
Cutter2020141996
Pomerene1020251968
Patagonia520251969
Dateland420251990
Palo Verde 2420242014
Skull Valley420241996
Carr Mtn420251986
Prescott320251979
Skull Valley 2320252025
Red Rock 2320192015
Antares320182002
Redington320251994
Willow Beach 2320252017
Sprucedale320251998
Cactus Forest320122005
New River220161998
Blue219891974
Alamo Res.220192003
Tonto Vill.220251992
Pinetop219931993
Araby220062004
Casa Grande220231989
Dragoon119961995
Portal120252014

Yellow Warbler Population Trend in Other States

alabamaalaskaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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