BirdAnalyst
Species · Illinois · BBS 2026 Release · 1966–2025

Rock Pigeon Population Trend in Illinois

All statesGeneralists

Rock Pigeon in Illinois has fallen sharply: down 73% on the route-weighted index since 1968.

-73%Since 1968TrendPercent 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 →
105Routes 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 →
59YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Rock Pigeon 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 declinecomputed 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 →

Rock Pigeon has fallen sharply in Illinois: down 73% on the route-weighted index since 1968.

Rock Pigeon Population Forecast in Illinois

If the recent trend holds, Rock Pigeon in Illinois is projected to fall about 85% by 2030 — from 3.9 in 2025 to a central estimate of 0.61 (95% range 0.00–6.2). A 5-year backtest shows a typical error of ±64.4%, with 100% of held-out values landing inside the 95% band.

-85%Change by 2030TrendPercent 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 →
0.61Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–6.295% 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 →
±64.4%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, Rock Pigeon in Illinois is projected to fall about 85% by 2030 — from 3.9 in 2025 to a central estimate of 0.61 (95% range 0.00–6.2). A 5-year backtest shows a typical error of ±64.4%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20261.80.007.4
20271.50.007.1
20281.20.006.8
20290.910.006.5
20300.610.006.2

Rock Pigeon Survey Routes in Illinois

Routes recording Rock Pigeon 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 →
Cherry Val6220031972
Camp Point6020171994
Itasca5120251966
Clarksdale3720221968
Mt Vernon2820221972
Humboldt2020251970
Caledonia2020251993
Union1920132001
Concord West1920162003
Harristown1820252001
Olney1620241969
Troy Grove1620251993
Mascoutah Lk1420251968
Sterling1320232001
Duncan Mills1220251994
Alden1220252019
Marshall1220232003
Fairdale1220252019
Fairbury1120251976
Jamestown1020251966
Melrose819991973
Birds820221977
Eldred820211993
Grape Creek820242004
Humphrey720251972

Rock Pigeon Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.