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

Chipping Sparrow Population Trend in Illinois

All statesGeneralists

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 →
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 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 68% by 2029 — from 12 in 2024 to a central estimate of 20 (95% range 16–24). A 5-year backtest shows a typical error of ±50.2%, with 0% of held-out values landing inside the 95% band.

+68%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 →
20Projected 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 →
16–2495% 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 →
±50.2%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 68% by 2029 — from 12 in 2024 to a central estimate of 20 (95% range 16–24). A 5-year backtest shows a typical error of ±50.2%, with 0% 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 →
2025191523
2026191524
2027201524
2028201624
2029201624

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 →
York4520241993
Sheffield3220241966
Union3120172001
Cherry Val3020031972
Guilford2820231969
Humboldt2720241981
Alden2620232019
Royalton2520242001
Belleview2420241966
Monticello2220241980
Newark2120221970
Cameron2120241967
Robinson2120231971
Mill Creek2020241966
Williamsfld2020241971
St Morgan2020221972
Cave In Rock2020241993
Sterling2020232001
Dailey1820221967
Concord1820241969
Sherrard1820241993
Lake Summerset1820222001
Chandlervill1720241971
Harristown1720242001
Humphrey1620241982

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 2026-05-22.