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

Eastern Towhee Population Trend in Illinois

All statesForest birds

Eastern Towhee in Illinois has increased: up 25% on the route-weighted index since 1968.

+25%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 →
101Routes 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 Eastern Towhee 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 →

No notable trend signals for Eastern Towhee in Illinois. See the full index history below.

Eastern Towhee Population Forecast in Illinois

If the recent trend holds, Eastern Towhee in Illinois is projected to rise about 30% by 2030 — from 1.5 in 2025 to a central estimate of 2.0 (95% range 0.79–3.2). A 5-year backtest shows a typical error of ±16%, with 100% of held-out values landing inside the 95% band.

+30%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 →
2.0Projected 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 →
0.79–3.295% 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 →
±16%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, Eastern Towhee in Illinois is projected to rise about 30% by 2030 — from 1.5 in 2025 to a central estimate of 2.0 (95% range 0.79–3.2). A 5-year backtest shows a typical error of ±16%, 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 →
20262.00.783.2
20272.00.783.2
20282.00.783.2
20292.00.793.2
20302.00.793.2

Eastern Towhee Survey Routes in Illinois

Routes recording Eastern Towhee 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 →
Delwood1620251970
Royalton1120252001
Brownville920251993
Bremen720251969
York720251993
Cave In Rock720241993
Kell720252001
Karnak720252001
Sheffield520241966
St Morgan520221967
Mt Vernon520251971
Guilford420231967
Cherry Val420031972
Chandlervill420221971
Birds420241976
Belknap420251970
Camp Point420231993
Sandusky420231993
Stillwell320241971
Terre Haute320251966
Belleview320251966
Bradbury320251971
Columbia320241967
Jamestown320221969
Yale320231994

Eastern Towhee Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiaindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

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