BirdAnalyst
Species · BCR 34 · BBS 2026 Release · 1966–2025

Western Tanager In Sierra Madre Occidental

All regionsSierra Madre OccidentalForest birds

Western Tanager in Sierra Madre Occidental has surged: up 702% on the route-weighted index since 1970.

+702%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 →
30Routes 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 →
55YearsYears 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 Sierra Madre Occidental: up 702% on the route-weighted index since 1970.

Western Tanager In Sierra Madre Occidental Population Forecast

If the recent trend holds, Western Tanager in Sierra Madre Occidental is projected to stay roughly flat through 2030, near 7.9 (95% range 3.8–12). A 5-year backtest shows a typical error of ±42.5%, with 80% of held-out values landing inside the 95% band.

-1%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 →
7.9Projected 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 →
3.8–1295% 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 →
±42.5%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 Madre Occidental is projected to stay roughly flat through 2030, near 7.9 (95% range 3.8–12). A 5-year backtest shows a typical error of ±42.5%, with 80% 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 →
20267.63.512
20277.73.512
20287.83.612
20297.93.712
20307.93.812

Routes In Sierra Madre Occidental

Routes recording Western Tanager in Sierra Madre Occidental.
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 →
WilliamsARIZONA342025
Mt. GrahamARIZONA282025
Happy JackARIZONA272025
ReserveNEW-MEXICO232025
FlagstaffARIZONA202025
SprucedaleARIZONA192025
Tonto Vill.ARIZONA172025
AlpineARIZONA172025
PinetopARIZONA102022
PrescottARIZONA72025
Aztec PeakARIZONA71978
BlueARIZONA71991
PortalARIZONA72025
RedingtonARIZONA52025
Emory PassNEW-MEXICO52025
PomereneARIZONA42022
Skull Valley 2ARIZONA32025
RuckerARIZONA32009
SunizonaARIZONA21986
MaineARIZONA22025
Forest LakesARIZONA22025
Carr MtnARIZONA22024
Mormon LakeARIZONA11975
Peña BlancaARIZONA12024
Skull ValleyARIZONA12011

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