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

Nashville Warbler In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionForest birds

Nashville Warbler in Prairie Hardwood Transition has declined: down 43% on the route-weighted index since 1968.

-43%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 →
41Routes 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 →

No notable trend signals for Nashville Warbler in Prairie Hardwood Transition. See the full index history below.

Forecast

If the recent trend holds, Nashville Warbler in Prairie Hardwood Transition is projected to fall about 69% by 2029 — from 0.14 in 2024 to a central estimate of 0.04 (95% range 0.00–0.22). A 5-year backtest shows a typical error of ±56.6%, with 100% of held-out values landing inside the 95% band.

-69%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 →
0.04Projected 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 →
0.00–0.2295% 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 →
±56.6%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, Nashville Warbler in Prairie Hardwood Transition is projected to fall about 69% by 2029 — from 0.14 in 2024 to a central estimate of 0.04 (95% range 0.00–0.22). A 5-year backtest shows a typical error of ±56.6%, with 100% 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 →
20250.060.000.24
20260.060.000.24
20270.050.000.23
20280.050.000.23
20290.040.000.22

Routes In Prairie Hardwood Transition

Routes recording Nashville Warbler 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 →
Pigeon CreekWISCONSIN102024
Barry S.G.A. 2MICHIGAN42015
LoraineWISCONSIN42018
EvergreenMINNESOTA32022
MerrillWISCONSIN32023
CadottWISCONSIN22024
HatfieldWISCONSIN21998
StratfordWISCONSIN21998
Stevens PtWISCONSIN22003
ClintonvilleWISCONSIN21996
CascoWISCONSIN22008
StetsonvilleWISCONSIN22015
ScottvilleMICHIGAN11996
Big Blue LkMICHIGAN12010
RemusMICHIGAN12024
No BradleyMICHIGAN11994
OlaMICHIGAN12000
Maple RapidsMICHIGAN12001
OwendaleMICHIGAN11979
HungerfordMICHIGAN12023
Chippewa Lk.MICHIGAN11996
Allegan WmaMICHIGAN12003
Barry S.G.A.MICHIGAN12012
EdwardsMINNESOTA11996
Brook ParkMINNESOTA11998

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