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

Summer Tanager Population Trend in Arizona

All statesGeneralists

Summer Tanager in Arizona has surged: up 93% on the route-weighted index since 1970.

+93%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 →
25Routes 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 Summer 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 →

Summer Tanager has surged in Arizona: up 93% on the route-weighted index since 1970.

Summer Tanager Population Forecast in Arizona

If the recent trend holds, Summer Tanager in Arizona is projected to fall about 15% by 2029 — from 0.83 in 2024 to a central estimate of 0.70 (95% range 0.29–1.1). A 5-year backtest shows a typical error of ±25.2%, with 100% of held-out values landing inside the 95% band.

-15%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 →
0.70Projected 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 →
0.29–1.195% 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 →
±25.2%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, Summer Tanager in Arizona is projected to fall about 15% by 2029 — from 0.83 in 2024 to a central estimate of 0.70 (95% range 0.29–1.1). A 5-year backtest shows a typical error of ±25.2%, 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 →
20250.690.281.1
20260.690.281.1
20270.700.291.1
20280.700.291.1
20290.700.291.1

Summer Tanager Survey Routes in Arizona

Routes recording Summer 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 →
Cutter 21320182015
Patagonia1020241968
Pomerene720241968
Amado420231993
Peña Blanca320241975
Skull Valley320241996
Cutter320141996
Redington320211993
Dragoon220091997
Portal220241976
Rucker220012000
Blue219861978
Sunizona219971968
Sahuarita220242012
Sprucedale220232017
Prescott120191979
Florence119881988
Riviera120161995
Maine119931993
Bartlett Res120222001
Mcneal120222014
Sunizona 2120242004
Peach Spring120231996
Casa Grande120111993
Carr Mtn120241985

Summer Tanager Population Trend in Other States

alabamaarkansascaliforniadelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamarylandmississippimissourinebraskanevadanew-jerseynew-mexiconorth-carolinaohiooklahomapennsylvaniasouth-carolinatennesseetexasutahvirginiawest-virginiawisconsin

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