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

Northern Bobwhite Population Trend in Illinois

All statesGrassland birds

Northern Bobwhite in Illinois has collapsed: down 80% on the route-weighted index since 1968.

-80%Since 1968
97Routes In State
58Years

Notable Northern Bobwhite Trends in Illinois

long arc declinecomputed index

Northern Bobwhite has collapsed in Illinois: down 80% on the route-weighted index since 1968.

Northern Bobwhite Population Forecast in Illinois

If the recent trend holds, Northern Bobwhite in Illinois is projected to fall about 95% by 2029 — from 6.6 in 2024 to a central estimate of 0.34 (95% range 0.00–11). A 5-year backtest shows a typical error of ±44.2%, with 100% of held-out values landing inside the 95% band.

-95%Change by 2029
0.34Projected 2029 index
0.00–1195% range
±44.2%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
20252.40.0013
20261.90.0013
20271.40.0012
20280.860.0012
20290.340.0011

Northern Bobwhite Survey Routes in Illinois

Routes recording Northern Bobwhite in Illinois.
Greenview3120241993
Athensville3020241971
Belleview3020241966
Kell2920242001
Chandlervill2420241971
Brownville2320241993
Marshall2320242001
Brnt Prairie2220241976
Mackinaw2120241966
Melrose2019991973
Concord2020241967
Concord West2020232001
Martinsville1920241970
Birds1920241976
Bradbury1820241970
Harristown1720242006
Sherrard1420231993
Mt Vernon1320241971
Beaucoup1220241971
Delwood1220241970
Robinson1220231970
Eldred1220211993
Bluff Spgs1120241967
York1120241993
Flora820241976

Northern Bobwhite Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawarefloridageorgiaidahoindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawashingtonwest-virginiawisconsinwyoming

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