BirdAnalyst
Species · BCR 34 · BBS 2025 Release · 1966–2024

Green-tailed Towhee In Sierra Madre Occidental

All regionsSierra Madre OccidentalGeneralists

Green-tailed Towhee in Sierra Madre Occidental has surged: up 270% on the route-weighted index since 1988.

+270%Since 1988TrendPercent 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 →
9Routes 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 →
28YearsYears 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 →

Green-tailed Towhee has surged in Sierra Madre Occidental: up 270% on the route-weighted index since 1988.

Forecast

If the recent trend holds, Green-tailed Towhee in Sierra Madre Occidental is projected to fall about 53% by 2028 — from 0.59 in 2023 to a central estimate of 0.28 (95% range 0.03–0.53). A 5-year backtest shows a typical error of ±38.9%, with 60% of held-out values landing inside the 95% band.

-53%Change by 2028TrendPercent 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 →
0.28Projected 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.03–0.5395% 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 →
±38.9%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, Green-tailed Towhee in Sierra Madre Occidental is projected to fall about 53% by 2028 — from 0.59 in 2023 to a central estimate of 0.28 (95% range 0.03–0.53). A 5-year backtest shows a typical error of ±38.9%, with 60% of held-out values landing inside the 95% band.19782028
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 →
20240.260.010.51
20250.260.010.52
20260.270.020.52
20270.270.020.53
20280.280.030.53

Routes In Sierra Madre Occidental

Routes recording Green-tailed Towhee 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 →
AlpineARIZONA132023
Happy JackARIZONA22002
SprucedaleARIZONA22021
FlagstaffARIZONA12022
BlueARIZONA11986
SunizonaARIZONA11997
MaineARIZONA12014
ReserveNEW-MEXICO12017
MagdalenaNEW-MEXICO12001

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