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

Hepatic Tanager Population Trend in Arizona

All statesForest birds

Hepatic Tanager in Arizona has surged: up 145% on the route-weighted index since 1971.

+145%Since 1971TrendPercent 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 →
28Routes 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 Hepatic Tanager 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 →

Hepatic Tanager has surged in Arizona: up 145% on the route-weighted index since 1971.

Hepatic Tanager Population Forecast in Arizona

If the recent trend holds, Hepatic Tanager in Arizona is projected to stay roughly flat through 2030, near 0.66 (95% range 0.10–1.2). A 5-year backtest shows a typical error of ±31%, with 100% of held-out values landing inside the 95% band.

-6%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 →
0.66Projected 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 →
0.10–1.295% 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 →
±31%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, Hepatic Tanager in Arizona is projected to stay roughly flat through 2030, near 0.66 (95% range 0.10–1.2). A 5-year backtest shows a typical error of ±31%, 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 →
20260.670.101.2
20270.660.101.2
20280.660.101.2
20290.660.101.2
20300.660.101.2

Hepatic Tanager Survey Routes in Arizona

Routes recording Hepatic Tanager 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 →
Rucker920091993
Portal720251975
Sprucedale620251996
Dragoon420091993
Maine420011995
Forest Lakes420251992
Clay Spring420242024
Blue319891987
Prescott220221976
Aztec Peak219781974
Peña Blanca220251975
Patagonia220251971
Sunizona219801968
Skull Valley220111998
Tonto Vill.220251992
Pinetop220222003
Flagstaff120251990
Sawmill120101990
Mormon Lake119751968
Skull Valley 2120252025
Williams120252001
Alpine120151994
Redington120112011
Mt. Graham120251995
Sahuarita120121992

Hepatic Tanager Population Trend in Other States

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