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

Northern Cardinal Population Trend in Illinois

All statesGeneralists

Northern Cardinal in Illinois has surged: up 75% on the route-weighted index since 1968.

+75%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 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 75% 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 15% by 2029 — from 29 in 2024 to a central estimate of 24 (95% range 19–29). A 5-year backtest shows a typical error of ±15.2%, with 60% of held-out values landing inside the 95% band.

-15%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 →
24Projected 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 →
19–2995% 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 →
±15.2%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, Northern Cardinal in Illinois is projected to fall about 15% by 2029 — from 29 in 2024 to a central estimate of 24 (95% range 19–29). A 5-year backtest shows a typical error of ±15.2%, with 60% 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 →
2025241929
2026241929
2027241929
2028241929
2029241929

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 →
Belknap10620241970
Royalton10220242001
Brownville8920241993
Mt Vernon7520241971
Bremen7020241969
Belleview6820241966
Pulaski6220241970
Brnt Prairie5720241976
St Morgan5220221967
Athensville4920241971
Beaverdam Lk4920231970
Kell4820242001
Mascoutah Lk4620241967
Lake Summerset4620222001
York4520241993
Wayne4420241966
Sandusky4420231993
Karnak4320242001
Bradbury4220241970
Cave In Rock4220241993
Athens4220241995
Delwood4020241970
Cherry Val3820031972
Eubanks3820242001
Melrose3619991973

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 2026-05-22.