BirdAnalyst
Species · BCR 28 · BBS 2025 Release · 1966–2024

Hermit Thrush In Appalachian Mountains

All regionsAppalachian MountainsForest birds

Hermit Thrush in Appalachian Mountains has surged: up 264% on the route-weighted index since 1968.

+264%Since 1968TrendPercent 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 →
150Routes 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 →
58YearsYears 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 Appalachian Mountains: up 264% on the route-weighted index since 1968.

Hermit Thrush In Appalachian Mountains Population Forecast

If the recent trend holds, Hermit Thrush in Appalachian Mountains is projected to rise about 53% by 2029 — from 0.84 in 2024 to a central estimate of 1.3 (95% range 0.72–1.8). A 5-year backtest shows a typical error of ±100.2%, with 0% of held-out values landing inside the 95% band.

+53%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 →
1.3Projected 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 →
0.72–1.895% 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 →
±100.2%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 Appalachian Mountains is projected to rise about 53% by 2029 — from 0.84 in 2024 to a central estimate of 1.3 (95% range 0.72–1.8). A 5-year backtest shows a typical error of ±100.2%, with 0% of held-out values landing inside the 95% band.19662029
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 →
20251.20.661.8
20261.20.681.8
20271.30.691.8
20281.30.711.8
20291.30.721.8

Routes In Appalachian Mountains

Routes recording Hermit Thrush in Appalachian Mountains.
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 →
OdinPENNSYLVANIA142024
GladyWEST-VIRGINIA132024
Glade Run 2WEST-VIRGINIA132024
LynchPENNSYLVANIA112024
RasselasPENNSYLVANIA112022
Marsh HillPENNSYLVANIA112024
DownsvilleNEW-YORK102019
Loft MtnVIRGINIA101994
Platte CoveNEW-YORK92018
Russell CityPENNSYLVANIA82024
AnsoniaPENNSYLVANIA82024
BemisWEST-VIRGINIA82024
Little MarshPENNSYLVANIA72024
Cherry SprsPENNSYLVANIA72023
StarlightPENNSYLVANIA71999
EllentonPENNSYLVANIA62024
Sproul Sf-BPENNSYLVANIA62024
CooperstownNEW-YORK51969
BusickNORTH-CAROLINA51995
RidgwayPENNSYLVANIA52018
Pocono SummitPENNSYLVANIA52024
Sproul Sf-APENNSYLVANIA52024
Glade RunWEST-VIRGINIA52002
N Pine GrovePENNSYLVANIA42024
RoulettePENNSYLVANIA42021

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