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

Rock Pigeon Population Trend in Illinois

All statesGeneralists

Rock Pigeon in Illinois has fallen sharply: down 71% on the route-weighted index since 1968.

-71%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 →
58YearsYears 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 71% 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 88% by 2029 — from 6.1 in 2024 to a central estimate of 0.76 (95% range 0.00–6.4). A 5-year backtest shows a typical error of ±51.9%, with 100% of held-out values landing inside the 95% band.

-88%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 →
0.76Projected 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 →
0.00–6.495% 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 →
±51.9%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 88% by 2029 — from 6.1 in 2024 to a central estimate of 0.76 (95% range 0.00–6.4). A 5-year backtest shows a typical error of ±51.9%, with 100% of held-out values landing inside the 95% band.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 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 →
20252.00.007.6
20261.70.007.3
20271.40.007.0
20281.10.006.7
20290.760.006.4

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 →
Itasca11620241966
Humboldt7420241970
Cherry Val6220031972
Camp Point6020171994
Alden5420232019
Clarksdale3720221968
Streator3220241973
Mt Vernon2820221972
Caledonia2620241993
Union1920132001
Concord West1920162003
Fairbury1620241976
Jamestown1620241966
Olney1620241969
Terre Haute1520241966
Humphrey1520241972
Harristown1520232001
Holcomb1320241971
Sterling1320232001
Mascoutah Lk1220241968
Marshall1220232003
Dailey920221968
Janesville920231972
Melrose819991973
Birds820221977

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 2026-05-22.