BirdAnalyst
Species · BCR 16 · BBS 2026 Release · 1966–2025

Western Tanager In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauForest birds

Western Tanager in Southern Rockies / Colorado Plateau has surged: up 213% on the route-weighted index since 1970.

+213%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 →
188Routes 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 →

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 Southern Rockies / Colorado Plateau: up 213% on the route-weighted index since 1970.

Western Tanager In Southern Rockies / Colorado Plateau Population Forecast

If the recent trend holds, Western Tanager in Southern Rockies / Colorado Plateau is projected to stay roughly flat through 2030, near 6.9 (95% range 5.2–8.5). A 5-year backtest shows a typical error of ±7%, 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 →
6.9Projected 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 →
5.2–8.595% 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%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 Southern Rockies / Colorado Plateau is projected to stay roughly flat through 2030, near 6.9 (95% range 5.2–8.5). A 5-year backtest shows a typical error of ±7%, 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 →
20266.54.98.2
20276.65.08.3
20286.75.08.4
20296.85.18.4
20306.95.28.5

Routes In Southern Rockies / Colorado Plateau

Routes recording Western Tanager in Southern Rockies / Colorado Plateau.
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 →
GallinasNEW-MEXICO422025
Dry ParkARIZONA392025
Dolores RivCOLORADO362025
Mcphee Res.COLORADO332025
Angel Fire 2NEW-MEXICO332025
TsaileARIZONA322023
Heeney 2COLORADO292025
Angel FireNEW-MEXICO272002
FerronUTAH272025
CokedaleCOLORADO262025
Red Spur Mtn.UTAH262023
South ForkCOLORADO252025
Dixie NfUTAH242025
Baxter PassCOLORADO232024
Gribbles PrkCOLORADO232025
Ojo SarcoNEW-MEXICO232025
Dunckley PasCOLORADO222025
HeeneyCOLORADO222019
Mt. TaylorNEW-MEXICO222012
Douglas PassCOLORADO212024
Cheesman LkCOLORADO212025
GooseberryUTAH202025
Bryce CanyonUTAH202025
Ryan ParkWYOMING202025
Deadman Rd.COLORADO192025

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