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Species · Illinois · BBS 2025 Release · 1966–2024

Kentucky Warbler Population Trend in Illinois

All statesForest birds

Kentucky Warbler in Illinois has surged: up 224% on the route-weighted index since 1970.

+224%Since 1970
47Routes In State
56Years

Notable Kentucky Warbler Trends in Illinois

long arc increasecomputed index

Kentucky Warbler has surged in Illinois: up 224% on the route-weighted index since 1970.

Kentucky Warbler Population Forecast in Illinois

If the recent trend holds, Kentucky Warbler in Illinois is projected to rise about 38% by 2029 — from 0.44 in 2024 to a central estimate of 0.61 (95% range 0.39–0.83). A 5-year backtest shows a typical error of ±22.7%, with 80% of held-out values landing inside the 95% band.

+38%Change by 2029
0.61Projected 2029 index
0.39–0.8395% range
±22.7%Backtest error
19682029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected index95% low95% high
20250.580.360.80
20260.590.360.81
20270.590.370.81
20280.600.380.82
20290.610.390.83

Kentucky Warbler Survey Routes in Illinois

Routes recording Kentucky Warbler in Illinois.
Sandusky1320231993
Cave In Rock820241993
Pulaski620241970
Delwood620241970
Belknap420241970
Beaverdam Lk420231970
Marshall420232011
Brownville420191999
Bremen320241970
York320231994
Terre Haute219851980
Eubanks220182001
Belleview220241969
Dudleyville220222006
Royalton220192001
Karnak220242002
Yale220141997
Athens120182001
Payson120242005
Clayton120032003
Williamsfld120172017
Grape Creek120232002
Dailey120172005
Melrose119921992
Bluff Spgs119731973

Kentucky Warbler Population Trend in Other States

alabamaarkansasdelawarefloridageorgiaindianaiowakansaskentuckylouisianamarylandmississippimissourinew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniasouth-carolinatennesseetexasvirginiawest-virginiawisconsin

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