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

Dickcissel Population Trend in Iowa

All statesGrassland birds

Dickcissel in Iowa has declined: down 41% on the route-weighted index since 1969.

-41%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 →
39Routes 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 Dickcissel 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 →

No notable trend signals for Dickcissel in Iowa. See the full index history below.

Dickcissel Population Forecast in Iowa

If the recent trend holds, Dickcissel in Iowa is projected to fall about 25% by 2030 — from 50 in 2025 to a central estimate of 37 (95% range 1.1–74). A 5-year backtest shows a typical error of ±37.4%, with 100% of held-out values landing inside the 95% band.

-25%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 →
37Projected 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 →
1.1–7495% 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 →
±37.4%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, Dickcissel in Iowa is projected to fall about 25% by 2030 — from 50 in 2025 to a central estimate of 37 (95% range 1.1–74). A 5-year backtest shows a typical error of ±37.4%, with 100% 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 →
2026382.075
2027381.874
2028381.574
2029381.374
2030371.174

Dickcissel Survey Routes in Iowa

Routes recording Dickcissel 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 →
College Spgs11820041967
Williamsburg11720231967
Wales10620251967
Titonka9220251968
Brooklyn8520251967
Kanawha8020251967
College Spgs 28020252005
Bryant7420251967
Washta7420251967
Tipton7120251993
Scranton6720251967
Neola6520251968
Red Rock6320251968
Bedford5920251968
Pierson5920251968
Panther5720251967
Zearing4619951967
Mccallsburg4420251996
Burchinal4320251995
Rock Valley4220251968
Hudson4120251967
West Liberty3820251968
Dinsdale3820251968
Cedar Valley3519971967
Mt Hamill3420251967

Dickcissel Population Trend in Other States

alabamaarkansascoloradodelawaregeorgiaillinoisindianakansaskentuckylouisianamarylandmichiganminnesotamississippimissourimontananebraskanew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniasouth-carolinasouth-dakotatennesseetexasvirginiawest-virginiawisconsinwyoming

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