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

Northern House Wren Population Trend in Iowa

All statesForest birds

Northern House Wren in Iowa has held roughly steady: up 9% on the route-weighted index since 1969.

+9%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 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 20% by 2029 — from 17 in 2024 to a central estimate of 13 (95% range 9.2–18). A 5-year backtest shows a typical error of ±13.5%, with 100% of held-out values landing inside the 95% band.

-20%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 →
13Projected 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 →
9.2–1895% 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 →
±13.5%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 20% by 2029 — from 17 in 2024 to a central estimate of 13 (95% range 9.2–18). A 5-year backtest shows a typical error of ±13.5%, 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 →
2025149.318
2026149.318
2027149.318
2028139.218
2029139.218

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 →
Red Rock3620241968
Lafayette3120242003
College Spgs 23020232005
Festina2720241968
Panther2220241967
Washta2220141967
Titonka2220241968
Melrose2120241974
Alice2119991967
Davis Corner2120241968
Mccallsburg2020241996
Maquoketa1820241967
Bryant1720241967
West Liberty1720241968
Mt Hamill1620241967
Exline1620241974
College Spgs1520041967
Sioux City1420241968
Gaza1420231969
Washington1320241967
Dinsdale1320241968
Hudson1220221967
Zearing1219951967
Rock Valley1220241968
Burchinal1220241995

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 2026-05-22.