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

Field Sparrow Population Trend in Iowa

All statesGeneralists

Field Sparrow in Iowa has fallen sharply: down 52% on the route-weighted index since 1969.

-52%Since 1969
38Routes In State
57Years

Notable Field Sparrow Trends in Iowa

long arc declinecomputed index

Field Sparrow has fallen sharply in Iowa: down 52% on the route-weighted index since 1969.

Field Sparrow Population Forecast in Iowa

If the recent trend holds, Field Sparrow in Iowa is projected to rise about 35% by 2029 — from 2.4 in 2024 to a central estimate of 3.2 (95% range 1.1–5.4). A 5-year backtest shows a typical error of ±63.3%, with 100% of held-out values landing inside the 95% band.

+35%Change by 2029
3.2Projected 2029 index
1.1–5.495% range
±63.3%Backtest error
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 index95% low95% high
20253.31.25.4
20263.31.25.4
20273.31.15.4
20283.31.15.4
20293.21.15.4

Field Sparrow Survey Routes in Iowa

Routes recording Field Sparrow in Iowa.
Washta2720141967
Mt Hamill1320241967
Bryant1220241967
Wales1020181967
Maquoketa820241967
Melrose720241974
Bedford620181968
Williamsburg620231967
Neola520161968
Pierson520191987
Festina520241968
Brooklyn420221967
Garner419921973
College Spgs 2420232005
West Liberty320241968
Alice319991967
Lafayette320192003
College Spgs220041967
Sioux City220191968
Davis Corner220241971
Exline120241974
Cedar Valley119971967
Red Rock120241968
Desmoines119791968
Panther120191973

Field Sparrow Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawarefloridageorgiaillinoisindianakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

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