BirdAnalyst
Species · Illinois · BBS 2025 Release · 1966–2024

Yellow-throated Warbler Population Trend in Illinois

All statesForest birds

Yellow-throated Warbler in Illinois has surged: up 267% on the route-weighted index since 1972.

+267%Since 1972TrendPercent 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 →
36Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
49YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Yellow-throated Warbler Trends in IllinoisNotable 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 →

Yellow-throated Warbler has surged in Illinois: up 267% on the route-weighted index since 1972.

Yellow-throated Warbler Population Forecast in Illinois

If the recent trend holds, Yellow-throated Warbler in Illinois is projected to fall about 16% by 2029 — from 0.17 in 2024 to a central estimate of 0.15 (95% range 0.04–0.25). A 5-year backtest shows a typical error of ±50.1%, with 60% of held-out values landing inside the 95% band.

-16%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 →
0.15Projected 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 →
0.04–0.2595% 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 →
±50.1%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, Yellow-throated Warbler in Illinois is projected to fall about 16% by 2029 — from 0.17 in 2024 to a central estimate of 0.15 (95% range 0.04–0.25). A 5-year backtest shows a typical error of ±50.1%, with 60% of held-out values landing inside the 95% band.19702029
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 →
20250.140.030.24
20260.140.030.25
20270.140.040.25
20280.140.040.25
20290.150.040.25

Yellow-throated Warbler Survey Routes in Illinois

Routes recording Yellow-throated Warbler in Illinois.
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 →
Belleview420242016
Jamestown319831982
St Morgan320221991
Athensville219921992
Birds220241979
Pulaski220241981
Cave In Rock220241994
Payson120212013
Clayton120192016
Sheffield119891989
Newark120222011
Stillwell120012001
Grape Creek120242005
Eubanks120152013
Dailey119951989
Martinsville119901990
Columbia120222009
Mascoutah Lk120182012
Beaucoup120232018
Brnt Prairie120012001
Mt Vernon119741974
Olney120071978
Flora120111985
Bremen120221994
Belknap120241971

Yellow-throated Warbler Population Trend in Other States

alabamaarkansascaliforniadelawarefloridageorgiaindianaiowakansaskentuckylouisianamarylandmichiganmississippimissourinew-jerseynorth-carolinaohiooklahomaoregonpennsylvaniasouth-carolinatennesseetexasvirginiawest-virginiawisconsin

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