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

Northern Cardinal Population Trend in Illinois

All statesForest birds

Northern Cardinal in Illinois has surged: up 80% on the route-weighted index since 1968.

+80%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 Northern Cardinal 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 →

Northern Cardinal has surged in Illinois: up 80% on the route-weighted index since 1968.

Northern Cardinal Population Forecast in Illinois

If the recent trend holds, Northern Cardinal in Illinois is projected to fall about 12% by 2030 — from 28 in 2025 to a central estimate of 25 (95% range 20–30). A 5-year backtest shows a typical error of ±18.4%, with 40% of held-out values landing inside the 95% band.

-12%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 →
25Projected 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 →
20–3095% 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 →
±18.4%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, Northern Cardinal in Illinois is projected to fall about 12% by 2030 — from 28 in 2025 to a central estimate of 25 (95% range 20–30). A 5-year backtest shows a typical error of ±18.4%, with 40% 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 →
2026241929
2027241930
2028251930
2029252030
2030252030

Northern Cardinal Survey Routes in Illinois

Routes recording Northern Cardinal 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 →
Belknap10320251970
Brownville9420251993
Brnt Prairie8620251976
Mt Vernon7120251971
Kell6820252001
Belleview6620251966
Bremen5820251969
Wayne5320251966
St Morgan5220221967
Royalton5020252001
Beaverdam Lk4920231970
Delwood4520251970
Sandusky4420231993
Athens4320251995
Cave In Rock4220241993
Athensville4120251971
Pulaski4120251970
Eubanks3920252001
Cherry Val3820031972
Humboldt3820251970
Bartonville3720251973
Concord3720251967
Melrose3619991973
Camp Point3620251993
Eldred3620251993

Northern Cardinal Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

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