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

Cerulean Warbler In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionForest birds

Cerulean Warbler in Prairie Hardwood Transition has declined: down 25% on the route-weighted index since 1970.

-25%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 →
45Routes 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 →
55YearsYears 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 Cerulean Warbler in Prairie Hardwood Transition. See the full index history below.

Forecast

If the recent trend holds, Cerulean Warbler in Prairie Hardwood Transition is projected to stay roughly flat through 2029, near 0.07 (95% range 0.01–0.13). A 5-year backtest shows a typical error of ±117.9%, with 80% 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 →
0.07Projected 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 →
0.01–0.1395% 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 →
±117.9%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, Cerulean Warbler in Prairie Hardwood Transition is projected to stay roughly flat through 2029, near 0.07 (95% range 0.01–0.13). A 5-year backtest shows a typical error of ±117.9%, with 80% of held-out values landing inside the 95% band.19672029
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 →
20250.070.010.13
20260.070.010.13
20270.070.010.13
20280.070.010.13
20290.070.010.13

Routes In Prairie Hardwood Transition

Routes recording Cerulean 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 →
NashvilleMICHIGAN32023
Barry S.G.A.MICHIGAN32012
Barry S.G.A. 2MICHIGAN32018
Indiana DuneINDIANA22022
New BuffaloMICHIGAN22013
Rolling PrWISCONSIN21976
KnoxINDIANA11990
KewannaINDIANA11983
PackertownINDIANA12004
EllisINDIANA12009
Packertown 2INDIANA12024
ScottvilleMICHIGAN12024
Big Blue LkMICHIGAN12007
LawrenceMICHIGAN11970
BravoMICHIGAN12022
GalesburgMICHIGAN11979
MontereyMICHIGAN12023
MottvilleMICHIGAN11987
No BradleyMICHIGAN11993
HomerMICHIGAN12015
FowlervilleMICHIGAN11979
RochesterMICHIGAN11997
HartlandMICHIGAN11998
Allegan WmaMICHIGAN12010
AlmenaMICHIGAN12014

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