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Species · Illinois · BBS 2025 Release · 1966–2024

Blue-gray Gnatcatcher Population Trend in Illinois

All statesForest birds

Blue-gray Gnatcatcher in Illinois has surged: up 18× on the route-weighted index since 1968.

18×Since 1968
97Routes In State
58Years

Notable Blue-gray Gnatcatcher Trends in Illinois

long arc increasecomputed index

Blue-gray Gnatcatcher has surged in Illinois: up 18× on the route-weighted index since 1968.

Blue-gray Gnatcatcher Population Forecast in Illinois

If the recent trend holds, Blue-gray Gnatcatcher in Illinois is projected to stay roughly flat through 2029, near 2.9 (95% range 2.2–3.6). A 5-year backtest shows a typical error of ±16%, with 80% of held-out values landing inside the 95% band.

+7%Change by 2029
2.9Projected 2029 index
2.2–3.695% range
±16%Backtest error
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 index95% low95% high
20252.72.03.4
20262.82.03.5
20272.82.13.5
20282.82.13.6
20292.92.23.6

Blue-gray Gnatcatcher Survey Routes in Illinois

Routes recording Blue-gray Gnatcatcher in Illinois.
Bremen2520241969
Royalton2020242001
Beaverdam Lk1920231970
Belleview1620241966
Cave In Rock1620241993
Pulaski1520241971
York1520241993
Robinson1220231997
Wayne1120232004
Mt Vernon920241973
Belknap920241973
Delwood920241973
Columbia820231970
Birds720241977
Sandusky720231993
Grape Creek720242002
Martinsville620241986
Beaucoup520241971
Marshall520242010
Terre Haute420241980
St Morgan420221969
New Lenox320172013
Dailey320171967
Eldred320191993
Brownville320241993

Blue-gray Gnatcatcher Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawest-virginiawisconsinwyoming

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