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

Sedge Wren Population Trend in Iowa

All statesGrassland birds

Sedge Wren in Iowa has surged: up 173% on the route-weighted index since 1970.

+173%Since 1970TrendPercent 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 →
55YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Sedge 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 →

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 →

Sedge Wren has surged in Iowa: up 173% on the route-weighted index since 1970.

Sedge Wren Population Forecast in Iowa

If the recent trend holds, Sedge Wren in Iowa is projected to rise about 52% by 2029 — from 0.59 in 2024 to a central estimate of 0.90 (95% range 0.14–1.7). A 5-year backtest shows a typical error of ±109.3%, with 100% of held-out values landing inside the 95% band.

+52%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 →
0.90Projected 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 →
0.14–1.795% 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 →
±109.3%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, Sedge Wren in Iowa is projected to rise about 52% by 2029 — from 0.59 in 2024 to a central estimate of 0.90 (95% range 0.14–1.7). A 5-year backtest shows a typical error of ±109.3%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20250.850.091.6
20260.860.101.6
20270.880.111.6
20280.890.121.7
20290.900.141.7

Sedge Wren Survey Routes in Iowa

Routes recording Sedge 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 →
Rock Valley820191988
Davis Corner720241970
Bedford620181991
Brooklyn420111983
Alice419991985
Kanawha420191999
Clare420191999
Wales320181993
Gaza320191993
College Spgs 2320102009
Melrose220102000
Burchinal220241995
Bryant219971970
Williamsburg220071973
Red Rock220101993
Panther220181990
Maquoketa220191968
Hudson220091985
Dinsdale220051981
Scranton220221971
Washta220101992
Festina220241968
Garner219881971
Titonka220241985
Mt Hamill120131996

Sedge Wren Population Trend in Other States

connecticutdelawareillinoisindianakansaskentuckymainemarylandmassachusettsmichiganminnesotamissourimontananebraskanew-hampshirenew-yorknorth-dakotaohiopennsylvaniasouth-dakotavermontvirginiawisconsin

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