BirdAnalyst
Species · BCR 22 · BBS 2025 Release · 1966–2024

Worm-eating Warbler In Eastern Tallgrass Prairie

All regionsEastern Tallgrass PrairieForest birds

Worm-eating Warbler in Eastern Tallgrass Prairie has held roughly steady: down 1% on the route-weighted index since 1982.

-1%Since 1982TrendPercent 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 →
18Routes 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 →
23YearsYears 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 Worm-eating Warbler in Eastern Tallgrass Prairie. See the full index history below.

Worm-eating Warbler In Eastern Tallgrass Prairie Population Forecast

If the recent trend holds, Worm-eating Warbler in Eastern Tallgrass Prairie is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.02). A 5-year backtest shows a typical error of ±54%, 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 →
0.01Projected 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 →
0.00–0.0295% 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 →
±54%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, Worm-eating Warbler in Eastern Tallgrass Prairie is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.02). A 5-year backtest shows a typical error of ±54%, with 80% of held-out values landing inside the 95% band.19762029
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 →
20250.010.000.02
20260.010.000.02
20270.010.000.02
20280.010.000.02
20290.010.000.02

Routes In Eastern Tallgrass Prairie

Routes recording Worm-eating Warbler in Eastern Tallgrass Prairie.
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 →
EmdenMISSOURI22019
House SpringsMISSOURI22024
NilwoodILLINOIS12014
PaysonILLINOIS12016
EubanksILLINOIS12010
MarshallILLINOIS12016
AthensILLINOIS12022
KokomoINDIANA12019
Mt HamillIOWA11979
DanvilleMISSOURI12009
OhioMISSOURI12006
HuntsvilleMISSOURI12019
KahokaMISSOURI11986
MillwoodMISSOURI12006
FrankfordMISSOURI12023
GeraldMISSOURI12021
MoselleMISSOURI12016
PeoriaOKLAHOMA11976

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