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

Abert's Towhee In Sierra Madre Occidental

All regionsSierra Madre OccidentalArid-land birds

Abert's Towhee in Sierra Madre Occidental has surged: up 82% on the route-weighted index since 1973.

+82%Since 1973TrendPercent 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 →
11Routes 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 →
47YearsYears 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 →

Abert's Towhee has surged in Sierra Madre Occidental: up 82% on the route-weighted index since 1973.

Abert's Towhee In Sierra Madre Occidental Population Forecast

If the recent trend holds, Abert's Towhee in Sierra Madre Occidental is projected to fall about 25% by 2030 — from 0.89 in 2025 to a central estimate of 0.67 (95% range 0.12–1.2). A 5-year backtest shows a typical error of ±42.9%, with 60% of held-out values landing inside the 95% band.

-25%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 →
0.67Projected 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 →
0.12–1.295% 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 →
±42.9%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, Abert's Towhee in Sierra Madre Occidental is projected to fall about 25% by 2030 — from 0.89 in 2025 to a central estimate of 0.67 (95% range 0.12–1.2). A 5-year backtest shows a typical error of ±42.9%, with 60% of held-out values landing inside the 95% band.19692030
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 →
20260.650.101.2
20270.650.101.2
20280.660.101.2
20290.660.111.2
20300.670.121.2

Routes In Sierra Madre Occidental

Routes recording Abert's 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 →
PomereneARIZONA142025
Bartlett ResARIZONA52025
SunizonaARIZONA31997
Carr MtnARIZONA32025
Peña BlancaARIZONA22022
CutterARIZONA22014
San SimonARIZONA12019
PatagoniaARIZONA12025
RedingtonARIZONA12025
AmadoARIZONA12017
SahuaritaARIZONA12024

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