BirdAnalyst
Species · BCR 15 · BBS 2026 Release · 1966–2025

Western Tanager In Sierra Nevada

All regionsSierra NevadaForest birds

Western Tanager in Sierra Nevada has held roughly steady: up 10% on the route-weighted index since 1970.

+10%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 →
40Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Western Tanager in Sierra Nevada. See the full index history below.

Western Tanager In Sierra Nevada Population Forecast

If the recent trend holds, Western Tanager in Sierra Nevada is projected to stay roughly flat through 2030, near 26 (95% range 18–34). A 5-year backtest shows a typical error of ±7.9%, with 100% of held-out values landing inside the 95% band.

-0%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 →
26Projected 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 →
18–3495% 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 →
±7.9%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, Western Tanager in Sierra Nevada is projected to stay roughly flat through 2030, near 26 (95% range 18–34). A 5-year backtest shows a typical error of ±7.9%, 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 →
2026251734
2027261834
2028261834
2029261834
2030261834

Routes In Sierra Nevada

Routes recording Western Tanager in Sierra Nevada.
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 →
JohnsvilleCALIFORNIA472025
PlacervilleCALIFORNIA442025
Eagle LakeCALIFORNIA432025
Pollock PinesCALIFORNIA392025
CrestviewCALIFORNIA392025
Pine MountainCALIFORNIA372017
LakeshoreCALIFORNIA352024
Greenhorn MtCALIFORNIA322008
Butte MeadowCALIFORNIA322014
Forest HillCALIFORNIA312025
GoumazCALIFORNIA302011
Silver CityCALIFORNIA292013
GeneseeCALIFORNIA292024
WoodfordsCALIFORNIA282025
Chaos CraterCALIFORNIA282019
Tuolumne GroveCALIFORNIA272025
Meadow ValleyCALIFORNIA272025
StrawberryCALIFORNIA252019
WestvilleCALIFORNIA242025
RivertonCALIFORNIA242025
ChilcootCALIFORNIA212024
DownievilleCALIFORNIA202025
LumberyardCALIFORNIA192025
Kings CanyonCALIFORNIA182024
Tahoe NfCALIFORNIA181994

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