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

Wood Duck Population Trend in Iowa

All statesWaterfowl

Wood Duck in Iowa has surged: up 347% on the route-weighted index since 1972.

+347%Since 1972TrendPercent 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 →
34Routes 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 →
52YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Wood Duck 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 →

Wood Duck has surged in Iowa: up 347% on the route-weighted index since 1972.

Wood Duck Population Forecast in Iowa

If the recent trend holds, Wood Duck in Iowa is projected to rise about 118% by 2029 — from 0.32 in 2024 to a central estimate of 0.69 (95% range 0.10–1.3). A 5-year backtest shows a typical error of ±63.4%, with 100% of held-out values landing inside the 95% band.

+118%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 →
0.69Projected 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 →
0.10–1.395% 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 →
±63.4%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, Wood Duck in Iowa is projected to rise about 118% by 2029 — from 0.32 in 2024 to a central estimate of 0.69 (95% range 0.10–1.3). A 5-year backtest shows a typical error of ±63.4%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20250.670.071.3
20260.670.081.3
20270.680.091.3
20280.690.091.3
20290.690.101.3

Wood Duck Survey Routes in Iowa

Routes recording Wood Duck 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 →
Panther1120231991
Neola419921979
Bedford320151972
Wales320181989
Dinsdale319901984
Tipton320172003
Mt Hamill220241983
Exline220191992
Maquoketa220221970
Prairieburg220171983
Hudson219961983
Kanawha220241982
Scranton220151979
Clare220191986
Washta220131988
Sioux City220241984
Festina220221983
Rock Valley220151979
College Spgs 2220192019
Melrose120211988
Burchinal120231995
Bryant120191969
West Liberty120151969
Brooklyn120141979
Red Rock120141988

Wood Duck Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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