BirdAnalyst
Species · BCR 35 · BBS 2026 Release · 1966–2025

Western Tanager In Chihuahuan Desert

All regionsChihuahuan DesertForest birds

Western Tanager in Chihuahuan Desert has surged: up 14× on the route-weighted index since 1977.

14×Since 1977TrendPercent 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 →
13Routes 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 →
46YearsYears 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 Chihuahuan Desert: up 14× on the route-weighted index since 1977.

Western Tanager In Chihuahuan Desert Population Forecast

If the recent trend holds, Western Tanager in Chihuahuan Desert is projected to stay roughly flat through 2030, near 2.0 (95% range 1.2–2.8). A 5-year backtest shows a typical error of ±23.1%, with 80% of held-out values landing inside the 95% band.

-3%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 →
2.0Projected 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 →
1.2–2.895% 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 →
±23.1%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 Chihuahuan Desert is projected to stay roughly flat through 2030, near 2.0 (95% range 1.2–2.8). A 5-year backtest shows a typical error of ±23.1%, with 80% of held-out values landing inside the 95% band.19742030
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 →
20261.91.12.7
20271.91.12.7
20282.01.22.8
20292.01.22.8
20302.01.22.8

Routes In Chihuahuan Desert

Routes recording Western Tanager in Chihuahuan Desert.
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 →
CloudcroftNEW-MEXICO682025
PinonNEW-MEXICO52024
Salt FlatTEXAS32013
RodeoNEW-MEXICO21974
Casa PiedraTEXAS22025
Bear MtnTEXAS22025
ToyahvaleTEXAS22025
CarrizozoNEW-MEXICO12025
RoswellNEW-MEXICO11974
Capitan Mtn.NEW-MEXICO12011
QueenNEW-MEXICO12021
AltudaTEXAS11980
MarfaTEXAS12019

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