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

Dickcissel Population Trend in Iowa

All statesGrassland birds

Dickcissel in Iowa has declined: down 36% on the route-weighted index since 1969.

-36%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 →
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 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 14% by 2029 — from 43 in 2024 to a central estimate of 37 (95% range 0.19–73). A 5-year backtest shows a typical error of ±41.6%, with 100% of held-out values landing inside the 95% band.

-14%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 →
37Projected 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 →
0.19–7395% 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 →
±41.6%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, Dickcissel in Iowa is projected to fall about 14% by 2029 — from 43 in 2024 to a central estimate of 37 (95% range 0.19–73). A 5-year backtest shows a typical error of ±41.6%, with 100% 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 →
2025381.274
2026370.9674
2027370.7074
2028370.4573
2029370.1973

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 →
Bedford14620181968
Brooklyn13320221967
College Spgs 212720232005
College Spgs11820041967
Williamsburg11720231967
Wales11620181967
Washta9120141967
Bryant8820241967
Kanawha8520241967
Scranton8020241967
Neola7520161968
Panther7020241967
Red Rock6320241968
Tipton6120241993
Gaza5720231969
West Liberty5520241968
Dinsdale5520241968
Zearing4619951967
Hudson4120221967
Mccallsburg4020241996
Exline3820241974
Lafayette3820242003
Titonka3720241968
Cedar Valley3519971967
Maquoketa3520241967

Dickcissel Population Trend in Other States

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

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.