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

American Robin Population Trend in Illinois

All statesForest birds

American Robin in Illinois has surged: up 84% on the route-weighted index since 1968.

+84%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 American Robin 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 →

American Robin has surged in Illinois: up 84% on the route-weighted index since 1968.

American Robin Population Forecast in Illinois

If the recent trend holds, American Robin in Illinois is projected to rise about 43% by 2029 — from 65 in 2024 to a central estimate of 93 (95% range 76–110). A 5-year backtest shows a typical error of ±42%, with 0% of held-out values landing inside the 95% band.

+43%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 →
93Projected 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 →
76–11095% 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 →
±42%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, American Robin in Illinois is projected to rise about 43% by 2029 — from 65 in 2024 to a central estimate of 93 (95% range 76–110). A 5-year backtest shows a typical error of ±42%, 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 →
20258972106
20269073107
20279174108
20289275109
20299376110

American Robin Survey Routes in Illinois

Routes recording American Robin 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 →
Sheffield16020241966
Terre Haute15620241966
Wayne14920241966
Atkinson13820241966
Caledonia13420241993
Harristown13320242001
New Lenox12520191966
Monticello12420241976
Pontiac12320241978
Newark12220221969
Fairland11620241967
Seneca11420241993
Buda11020231977
Itasca10820241966
Milford10820231966
Concord10520241967
Mackinaw10320241966
Streator10120241972
Troy Grove10020241993
Alden9920232019
Essex9820241969
Athensville9420241971
Humphrey9120241972
Grape Creek9120242001
Sterling9020232001

American Robin 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.