BirdAnalyst
Species · Arizona · BBS 2025 Release · 1966–2024

Hepatic Tanager Population Trend in Arizona

All statesGeneralists

Hepatic Tanager in Arizona has surged: up 133% on the route-weighted index since 1971.

+133%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 →
27Routes 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 →
54YearsYears 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 133% 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 fall about 26% by 2029 — from 0.89 in 2024 to a central estimate of 0.66 (95% range 0.09–1.2). A 5-year backtest shows a typical error of ±40.1%, with 100% of held-out values landing inside the 95% band.

-26%Change 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 →
0.66Projected 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 →
0.09–1.295% 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 →
±40.1%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 fall about 26% by 2029 — from 0.89 in 2024 to a central estimate of 0.66 (95% range 0.09–1.2). A 5-year backtest shows a typical error of ±40.1%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20250.660.101.2
20260.660.101.2
20270.660.101.2
20280.660.091.2
20290.660.091.2

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 →
Happy Jack1220241977
Rucker920091993
Portal720241975
Flagstaff720221990
Dragoon420091993
Maine420011995
Forest Lakes420241992
Clay Spring420242024
Blue319891987
Tonto Vill.320211992
Prescott220221976
Aztec Peak219781974
Peña Blanca220241975
Sunizona219801968
Skull Valley220111998
Pinetop220222003
Sprucedale220231996
Sawmill120101990
Mormon Lake119751968
Patagonia120241971
Williams120182001
Alpine120151994
Redington120112011
Mt. Graham120231995
Sahuarita120121992

Hepatic Tanager Population Trend in Other States

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