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

Northern Cardinal Population Trend in Iowa

All statesForest birds

Northern Cardinal in Iowa has surged: up 95% on the route-weighted index since 1969.

+95%Since 1969TrendPercent 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 →
38Routes 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 IowaNotable 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 Iowa: up 95% on the route-weighted index since 1969.

Northern Cardinal Population Forecast in Iowa

If the recent trend holds, Northern Cardinal in Iowa is projected to stay roughly flat through 2030, near 12 (95% range 8.5–16). A 5-year backtest shows a typical error of ±27.6%, with 40% of held-out values landing inside the 95% band.

-10%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 →
12Projected 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 →
8.5–1695% 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 →
±27.6%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 Iowa is projected to stay roughly flat through 2030, near 12 (95% range 8.5–16). A 5-year backtest shows a typical error of ±27.6%, with 40% of held-out values landing inside the 95% band.19672030
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 →
2026128.216
2027128.316
2028128.416
2029128.516
2030128.516

Northern Cardinal Survey Routes in Iowa

Routes recording Northern Cardinal in Iowa.
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 →
Red Rock5720251968
Hudson3320251967
Wales3120251967
Mt Hamill3020251967
College Spgs2720041967
Alice2619991967
College Spgs 22620252005
Festina2320251968
West Liberty1920251968
Maquoketa1920251967
Bryant1820251967
Panther1720251967
Neola1520251968
Lafayette1520252003
Mccallsburg1420251996
Bedford1220251968
Tipton1220251993
Exline1120251974
Melrose1120251974
Cedar Valley1119971967
Washington1120251967
Davis Corner920251970
Williamsburg720231967
Dinsdale720251968
Brooklyn620251967

Northern Cardinal Population Trend in Other States

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

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