BirdAnalyst
Species · BCR 9 · BBS 2025 Release · 1966–2024

Western Tanager In Great Basin

All regionsGreat BasinGeneralists

Western Tanager in Great Basin has surged: up 134% on the route-weighted index since 1970.

+134%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 →
170Routes 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 →
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 SignalsNotable 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 →

Western Tanager has surged in Great Basin: up 134% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Western Tanager in Great Basin is projected to stay roughly flat through 2029, near 7.1 (95% range 5.4–8.8). A 5-year backtest shows a typical error of ±8.1%, with 100% of held-out values landing inside the 95% band.

+10%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 →
7.1Projected 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 →
5.4–8.895% 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 →
±8.1%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, Western Tanager in Great Basin is projected to stay roughly flat through 2029, near 7.1 (95% range 5.4–8.8). A 5-year backtest shows a typical error of ±8.1%, 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 →
20256.85.18.5
20266.85.18.5
20276.95.28.6
20287.05.38.7
20297.15.48.8

Routes In Great Basin

Routes recording Western Tanager in Great Basin.
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 →
Blewett PassWASHINGTON1012024
Badger CreekOREGON662024
BartleCALIFORNIA482021
E. Mt. AdamsWASHINGTON482024
LakeviewOREGON472024
CarltonWASHINGTON462022
Barnes ValOREGON411987
Mt HoodOREGON402024
RimrockWASHINGTON392024
RonaldWASHINGTON332024
SnowdenWASHINGTON322024
KendallWASHINGTON292024
MazamaWASHINGTON292022
PaisleyOREGON282024
LeavenworthWASHINGTON272024
Davis CreekCALIFORNIA262024
L. WenatcheeWASHINGTON262024
GlacierWASHINGTON242024
TionestaCALIFORNIA232021
WinthropWASHINGTON232022
Bly 2OREGON222024
SistersOREGON222024
Index 2WASHINGTON222023
Suiattle RivWASHINGTON212019
Cascade RivWASHINGTON202006

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