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

Blue-winged Warbler In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionForest birds

Blue-winged Warbler in Prairie Hardwood Transition has surged: up 376% on the route-weighted index since 1968.

+376%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 →
111Routes 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 →

Blue-winged Warbler has surged in Prairie Hardwood Transition: up 376% on the route-weighted index since 1968.

Blue-winged Warbler In Prairie Hardwood Transition Population Forecast

If the recent trend holds, Blue-winged Warbler in Prairie Hardwood Transition is projected to stay roughly flat through 2029, near 0.70 (95% range 0.49–0.91). A 5-year backtest shows a typical error of ±3.7%, with 100% of held-out values landing inside the 95% band.

+6%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 →
0.70Projected 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 →
0.49–0.9195% 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 →
±3.7%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, Blue-winged Warbler in Prairie Hardwood Transition is projected to stay roughly flat through 2029, near 0.70 (95% range 0.49–0.91). A 5-year backtest shows a typical error of ±3.7%, 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 →
20250.670.460.87
20260.680.470.88
20270.680.480.89
20280.690.480.90
20290.700.490.91

Routes In Prairie Hardwood Transition

Routes recording Blue-winged 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 →
MontereyMICHIGAN92023
Pigeon CreekWISCONSIN92024
Caledonia 2MINNESOTA82024
GilmantonWISCONSIN72024
MatherWISCONSIN72023
N FreedomWISCONSIN72024
Barry S.G.A.MICHIGAN62012
AlmenaMICHIGAN42014
CaledoniaMINNESOTA42009
CumberlandWISCONSIN42024
CochraneWISCONSIN42022
CadottWISCONSIN42024
ClintonvilleWISCONSIN42016
BravoMICHIGAN32023
NashvilleMICHIGAN32023
RichmondMICHIGAN32010
Chippewa Lk.MICHIGAN32023
Chatfield 2MINNESOTA32024
WhitewaterMINNESOTA32000
EsdaileWISCONSIN32024
ViroquaWISCONSIN32024
Prairie Du ChienWISCONSIN32021
Lake GalenaILLINOIS22021
LawrenceMICHIGAN22004
RemusMICHIGAN22024

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