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

Northern Cardinal Population Trend in Iowa

All statesGeneralists

Northern Cardinal in Iowa has surged: up 99% on the route-weighted index since 1969.

+99%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 →
57YearsYears 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 99% 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 fall about 18% by 2029 — from 15 in 2024 to a central estimate of 12 (95% range 8.3–16). A 5-year backtest shows a typical error of ±30%, with 0% of held-out values landing inside the 95% band.

-18%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 →
12Projected 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 →
8.3–1695% 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 →
±30%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 fall about 18% by 2029 — from 15 in 2024 to a central estimate of 12 (95% range 8.3–16). A 5-year backtest shows a typical error of ±30%, with 0% of held-out values landing inside the 95% band.19672029
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 →
2025128.015
2026128.115
2027128.116
2028128.216
2029128.316

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 Rock6920241968
College Spgs 23820232005
West Liberty2920241968
College Spgs2720041967
Hudson2720221967
Melrose2620241974
Alice2619991967
Mt Hamill2220241967
Festina2120241968
Lafayette2120242003
Maquoketa1920241967
Sioux City1720241968
Exline1520241974
Panther1520241967
Neola1220161968
Mccallsburg1220241996
Bryant1120241967
Cedar Valley1119971967
Washington1120241967
Washta1020141967
Brooklyn920221967
Davis Corner920241970
Tipton920241993
Prairieburg820241967
Williamsburg720231967

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 2026-05-22.