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

Black-throated Gray Warbler In Sierra Madre Occidental

All regionsSierra Madre OccidentalForest birds

Black-throated Gray Warbler in Sierra Madre Occidental has risen sharply: up 63% on the route-weighted index since 1974.

+63%Since 1974TrendPercent 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 →
26Routes 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 →
53YearsYears 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 →

Black-throated Gray Warbler has risen sharply in Sierra Madre Occidental: up 63% on the route-weighted index since 1974.

Black-throated Gray Warbler In Sierra Madre Occidental Population Forecast

If the recent trend holds, Black-throated Gray Warbler in Sierra Madre Occidental is projected to fall about 35% by 2030 — from 3.6 in 2025 to a central estimate of 2.4 (95% range 0.45–4.3). A 5-year backtest shows a typical error of ±45.9%, with 80% of held-out values landing inside the 95% band.

-35%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 →
2.4Projected 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 →
0.45–4.395% 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 →
±45.9%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, Black-throated Gray Warbler in Sierra Madre Occidental is projected to fall about 35% by 2030 — from 3.6 in 2025 to a central estimate of 2.4 (95% range 0.45–4.3). A 5-year backtest shows a typical error of ±45.9%, with 80% of held-out values landing inside the 95% band.19702030
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 →
20262.40.434.3
20272.40.444.3
20282.40.444.3
20292.40.444.3
20302.40.454.3

Routes In Sierra Madre Occidental

Routes recording Black-throated Gray Warbler 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 →
Tonto Vill.ARIZONA282025
ReserveNEW-MEXICO172025
WilliamsARIZONA132025
PortalARIZONA112025
Carr MtnARIZONA92025
Aztec PeakARIZONA61978
SprucedaleARIZONA62025
SunizonaARIZONA51997
Forest LakesARIZONA52025
Mt. GrahamARIZONA42025
RuckerARIZONA32009
Mormon LakeARIZONA21974
PinetopARIZONA22021
Sunizona 2ARIZONA22022
Emory PassNEW-MEXICO22025
FlagstaffARIZONA12009
PrescottARIZONA12025
BlueARIZONA11991
PatagoniaARIZONA12019
MaineARIZONA12005
AlpineARIZONA12021
Happy JackARIZONA12025
Clay SpringARIZONA12012
Skull Valley 2ARIZONA12025
DragoonARIZONA12009

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