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

Chipping Sparrow Population Trend in Illinois

All statesForest birds

Chipping Sparrow in Illinois has surged: up 13× on the route-weighted index since 1968.

13×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 Chipping Sparrow 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 increasecomputed 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 →

Chipping Sparrow has surged in Illinois: up 13× on the route-weighted index since 1968.

Chipping Sparrow Population Forecast in Illinois

If the recent trend holds, Chipping Sparrow in Illinois is projected to rise about 46% by 2030 — from 14 in 2025 to a central estimate of 20 (95% range 16–25). A 5-year backtest shows a typical error of ±52.8%, with 0% of held-out values landing inside the 95% band.

+46%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 →
20Projected 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 →
16–2595% 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 →
±52.8%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, Chipping Sparrow in Illinois is projected to rise about 46% by 2030 — from 14 in 2025 to a central estimate of 20 (95% range 16–25). A 5-year backtest shows a typical error of ±52.8%, with 0% 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 →
2026191423
2027191524
2028191524
2029201524
2030201625

Chipping Sparrow Survey Routes in Illinois

Routes recording Chipping Sparrow 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 →
York5920251993
Sheffield3220241966
Bremen3120251969
Union3120172001
Cherry Val3020031972
Guilford2820231969
Belleview2820251966
Brownville2520251993
Mt Vernon2420251972
Royalton2420252001
Cameron2320251967
Humboldt2320251981
Newark2120221970
Terre Haute2120251967
Williamsfld2120251971
Robinson2120231971
St Morgan2020221972
Sherrard2020251993
Cave In Rock2020241993
Sterling2020232001
Monticello1920251980
Dailey1920251967
Bluff Spgs1920251970
Brnt Prairie1920251976
Alden1920252019

Chipping Sparrow 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.