BirdAnalyst
Species · BCR 23 · BBS 2025 Release · 1966–2024

Hermit Thrush In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionForest birds

Hermit Thrush in Prairie Hardwood Transition has surged: up 274% on the route-weighted index since 1968.

+274%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 →
30Routes 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 →
56YearsYears 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 Prairie Hardwood Transition: up 274% on the route-weighted index since 1968.

Hermit Thrush In Prairie Hardwood Transition Population Forecast

If the recent trend holds, Hermit Thrush in Prairie Hardwood Transition is projected to stay roughly flat through 2029, near 0.19 (95% range 0.03–0.34). A 5-year backtest shows a typical error of ±363.6%, with 40% of held-out values landing inside the 95% band.

n/aChange 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 →
0.19Projected 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 →
0.03–0.3495% 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 →
±363.6%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 Prairie Hardwood Transition is projected to stay roughly flat through 2029, near 0.19 (95% range 0.03–0.34). A 5-year backtest shows a typical error of ±363.6%, with 40% 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 →
20250.180.020.33
20260.180.030.33
20270.180.030.34
20280.180.030.34
20290.190.030.34

Routes In Prairie Hardwood Transition

Routes recording Hermit Thrush in Prairie Hardwood Transition.
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 →
HatfieldWISCONSIN91998
MatherWISCONSIN42019
MerrillWISCONSIN32008
Big RapidsMICHIGAN21981
Chippewa Lk.MICHIGAN21992
Barry S.G.A.MICHIGAN21999
ElderonWISCONSIN22003
ScottvilleMICHIGAN12023
BeldingMICHIGAN12002
MontereyMICHIGAN12011
No BradleyMICHIGAN11989
Maple RapidsMICHIGAN11994
HungerfordMICHIGAN12017
Belding 2MICHIGAN12005
Allegan WmaMICHIGAN11996
MillvilleMINNESOTA12010
EvergreenMINNESOTA12024
Brook ParkMINNESOTA11999
LoraineWISCONSIN12018
CumberlandWISCONSIN12018
CadottWISCONSIN12019
StratfordWISCONSIN12015
Wis RapidsWISCONSIN12022
Stevens PtWISCONSIN12023
ManawaWISCONSIN12007

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