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Species · Iowa · BBS 2026 Release · 1966–2025

Northern House Wren Population Trend in Iowa

All statesForest birds

Northern House Wren in Iowa has edged up: up 15% on the route-weighted index since 1969.

+15%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 Northern House Wren 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 Northern House Wren in Iowa. See the full index history below.

Northern House Wren Population Forecast in Iowa

If the recent trend holds, Northern House Wren in Iowa is projected to fall about 17% by 2030 — from 17 in 2025 to a central estimate of 14 (95% range 9.4–18). A 5-year backtest shows a typical error of ±12.4%, with 100% of held-out values landing inside the 95% band.

-17%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 →
14Projected 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 →
9.4–1895% 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 →
±12.4%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, Northern House Wren in Iowa is projected to fall about 17% by 2030 — from 17 in 2025 to a central estimate of 14 (95% range 9.4–18). A 5-year backtest shows a typical error of ±12.4%, 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 →
2026149.518
2027149.518
2028149.418
2029149.418
2030149.418

Northern House Wren Survey Routes in Iowa

Routes recording Northern House Wren 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 →
Festina3520251968
Washta3220251967
Hudson3120251967
Red Rock2920251968
College Spgs 22920252005
Mt Hamill2820251967
Panther2520251967
Davis Corner2520251968
Pierson2220251968
Alice2119991967
Melrose2020251974
Wales1820251967
Mccallsburg1820251996
Bedford1720251968
Maquoketa1720251967
Bryant1620251967
West Liberty1620251968
Lafayette1620252003
College Spgs1520041967
Sioux City1520251968
Titonka1520251968
Exline1320251974
Dinsdale1220251968
Zearing1219951967
Kanawha1120251967

Northern House Wren Population Trend in Other States

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

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