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

Hermit Thrush In Sierra Madre Occidental

All regionsSierra Madre OccidentalForest birds

Hermit Thrush in Sierra Madre Occidental has increased: up 50% on the route-weighted index since 1970.

+50%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 →
23Routes 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 Hermit Thrush in Sierra Madre Occidental. See the full index history below.

Forecast

If the recent trend holds, Hermit Thrush in Sierra Madre Occidental is projected to rise about 982% by 2029 — from 0.50 in 2024 to a central estimate of 5.4 (95% range 0.14–11). A 5-year backtest shows a typical error of ±333.4%, with 80% of held-out values landing inside the 95% band.

+982%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 →
5.4Projected 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 →
0.14–1195% 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 →
±333.4%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, Hermit Thrush in Sierra Madre Occidental is projected to rise about 982% by 2029 — from 0.50 in 2024 to a central estimate of 5.4 (95% range 0.14–11). A 5-year backtest shows a typical error of ±333.4%, with 80% 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 →
20255.30.0311
20265.30.0611
20275.40.0911
20285.40.1111
20295.40.1411

Routes In Sierra Madre Occidental

Routes recording Hermit Thrush 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 →
Mt. GrahamARIZONA302023
Aztec PeakARIZONA111978
AlpineARIZONA112023
ReserveNEW-MEXICO102023
RuckerARIZONA92009
PrescottARIZONA52022
BlueARIZONA51991
Emory PassNEW-MEXICO52024
Mormon LakeARIZONA41975
SprucedaleARIZONA42023
FlagstaffARIZONA32022
WilliamsARIZONA32019
Tonto Vill.ARIZONA32019
PinetopARIZONA32014
Carr MtnARIZONA32011
Happy JackARIZONA22024
PortalARIZONA22024
MaineARIZONA12009
Forest LakesARIZONA12016
Clay SpringARIZONA12003
Sunizona 2ARIZONA12010
DragoonARIZONA11996
Vicks PeakNEW-MEXICO12018

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