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

House Sparrow Population Trend in Illinois

All statesGeneralists

House Sparrow in Illinois has collapsed: down 82% on the route-weighted index since 1968.

-82%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 House 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 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 →

House Sparrow has collapsed in Illinois: down 82% on the route-weighted index since 1968.

House Sparrow Population Forecast in Illinois

If the recent trend holds, House Sparrow in Illinois is projected to fall about 100% by 2029 — from 59 in 2024 to a central estimate of 0.00 (95% range 0.00–41). A 5-year backtest shows a typical error of ±76.3%, with 40% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–4195% 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 →
±76.3%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, House Sparrow in Illinois is projected to fall about 100% by 2029 — from 59 in 2024 to a central estimate of 0.00 (95% range 0.00–41). A 5-year backtest shows a typical error of ±76.3%, with 40% 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 →
20259.90.0051
20265.40.0047
20270.860.0042
20280.000.0041
20290.000.0041

House Sparrow Survey Routes in Illinois

Routes recording House 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 →
Itasca32920241966
Atkinson22920241966
Caledonia19320241993
Beaucoup17020241971
Sterling14220232001
Sheffield13820241966
Wayne13720241966
York13720241993
Yale12620241993
Jamestown12120241966
Sherrard11920241993
Marshall11720242001
Cameron11520241966
Pontiac10920241978
Janesville10420241972
Barrington9920121967
Geneseo9520211967
Humboldt9120241970
Darmstadt8720241993
Terre Haute8520241966
Newark8420221969
Eldred8320211993
St Morgan8120221967
Bartonville8020241973
Seneca7920241993

House 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.