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

American Redstart Population Trend in Iowa

All statesForest birds

American Redstart in Iowa has surged: up 17× on the route-weighted index since 1971.

17×Since 1971TrendPercent 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 →
23Routes 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 American Redstart 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 →

American Redstart has surged in Iowa: up 17× on the route-weighted index since 1971.

American Redstart Population Forecast in Iowa

If the recent trend holds, American Redstart in Iowa is projected to fall about 39% by 2029 — from 0.82 in 2024 to a central estimate of 0.49 (95% range 0.15–0.83). A 5-year backtest shows a typical error of ±50%, with 40% of held-out values landing inside the 95% band.

-39%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 →
0.49Projected 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 →
0.15–0.8395% 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 →
±50%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, American Redstart in Iowa is projected to fall about 39% by 2029 — from 0.82 in 2024 to a central estimate of 0.49 (95% range 0.15–0.83). A 5-year backtest shows a typical error of ±50%, with 40% 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 →
20250.460.120.81
20260.470.130.81
20270.480.140.82
20280.490.150.83
20290.490.150.83

American Redstart Survey Routes in Iowa

Routes recording American Redstart 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 →
Maquoketa620241992
West Liberty420241970
Mccallsburg420192019
Cedar Valley219951971
Festina220241968
Lafayette220242003
Mt Hamill120172017
Exline120222014
Melrose120022002
Brooklyn120132010
Williamsburg120081975
Red Rock120092009
Panther120242009
Washington120242021
Alice119991975
Prairieburg120172017
Dinsdale120242012
Scranton120172017
Clare120082007
Washta120142008
Davis Corner120232021
College Spgs 2120212013
Tipton120241994

American Redstart Population Trend in Other States

alabamaalaskaarkansascoloradoconnecticutdelawaregeorgiaidahoillinoisindianakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawashingtonwest-virginiawisconsinwyoming

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