BirdAnalyst
Species · BCR 16 · BBS 2026 Release · 1966–2025

Hermit Thrush In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauForest birds

Hermit Thrush in Southern Rockies / Colorado Plateau has surged: up 274% on the route-weighted index since 1970.

+274%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 →
142Routes 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 →
57YearsYears 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 →

Hermit Thrush has surged in Southern Rockies / Colorado Plateau: up 274% on the route-weighted index since 1970.

Hermit Thrush In Southern Rockies / Colorado Plateau Population Forecast

If the recent trend holds, Hermit Thrush in Southern Rockies / Colorado Plateau is projected to rise about 65% by 2030 — from 4.9 in 2025 to a central estimate of 8.1 (95% range 5.7–10). A 5-year backtest shows a typical error of ±48.2%, with 40% of held-out values landing inside the 95% band.

+65%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 →
8.1Projected 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 →
5.7–1095% 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 →
±48.2%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 Southern Rockies / Colorado Plateau is projected to rise about 65% by 2030 — from 4.9 in 2025 to a central estimate of 8.1 (95% range 5.7–10). A 5-year backtest shows a typical error of ±48.2%, with 40% of held-out values landing inside the 95% band.19682030
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 →
20267.75.310
20277.85.410
20287.95.510
20298.05.610
20308.15.710

Routes In Southern Rockies / Colorado Plateau

Routes recording Hermit Thrush in Southern Rockies / Colorado Plateau.
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 →
Dry ParkARIZONA512025
Pinos CreekCOLORADO441990
FerronUTAH392025
Mcphee Res.COLORADO372025
TsaileARIZONA342023
Mount EvansCOLORADO342024
Fox ParkWYOMING342025
Navajo LakeUTAH322025
Guanella PasCOLORADO282025
Angel FireNEW-MEXICO262002
Ryan ParkWYOMING262025
Baxter PassCOLORADO252024
PinonCOLORADO242025
La SalUTAH242000
Red Spur Mtn.UTAH232023
Lake CityCOLORADO222003
Grizzly RdgeUTAH212025
Wasatch NfUTAH212024
Heeney 2COLORADO202025
La Sal 2UTAH202006
Haycamp MesaCOLORADO192025
MonticelloUTAH192025
Buffalo ParkCOLORADO182025
Cochetopa PassCOLORADO162025
SoapstoneUTAH162025

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