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

Grace's Warbler In Sierra Madre Occidental

All regionsSierra Madre OccidentalForest birds

Grace's Warbler in Sierra Madre Occidental has edged down: down 23% on the route-weighted index since 1970.

-23%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 →
21Routes 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 →
54YearsYears 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 →

No notable trend signals for Grace's Warbler in Sierra Madre Occidental. See the full index history below.

Grace's Warbler In Sierra Madre Occidental Population Forecast

If the recent trend holds, Grace's Warbler in Sierra Madre Occidental is projected to stay roughly flat through 2029, near 4.3 (95% range 1.3–7.2). A 5-year backtest shows a typical error of ±14.5%, with 100% of held-out values landing inside the 95% band.

-7%Change by 2029TrendPercent 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 →
4.3Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
1.3–7.295% 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 →
±14.5%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, Grace's Warbler in Sierra Madre Occidental is projected to stay roughly flat through 2029, near 4.3 (95% range 1.3–7.2). A 5-year backtest shows a typical error of ±14.5%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20254.31.47.3
20264.31.47.3
20274.31.37.3
20284.31.37.3
20294.31.37.2

Routes In Sierra Madre Occidental

Routes recording Grace's 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 →
Happy JackARIZONA622024
Tonto Vill.ARIZONA232021
SprucedaleARIZONA212023
Aztec PeakARIZONA161978
ReserveNEW-MEXICO152023
Mt. GrahamARIZONA142023
RuckerARIZONA112009
AlpineARIZONA102023
Forest LakesARIZONA92024
FlagstaffARIZONA82022
PrescottARIZONA72022
Carr MtnARIZONA62024
PortalARIZONA52024
BlueARIZONA31991
SunizonaARIZONA31975
WilliamsARIZONA32018
MaineARIZONA22021
PinetopARIZONA22022
Vicks PeakNEW-MEXICO22021
Mormon LakeARIZONA11975
Emory PassNEW-MEXICO12024

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