BirdAnalyst
Species · Iowa · BBS 2026 Release · 1966–2025

American Robin Population Trend in Iowa

All statesForest birds

American Robin in Iowa has surged: up 165% on the route-weighted index since 1969.

+165%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 American Robin 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 Robin has surged in Iowa: up 165% on the route-weighted index since 1969.

American Robin Population Forecast in Iowa

If the recent trend holds, American Robin in Iowa is projected to stay roughly flat through 2030, near 89 (95% range 78–100). A 5-year backtest shows a typical error of ±8.3%, with 100% of held-out values landing inside the 95% band.

+8%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 →
89Projected 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 →
78–10095% 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 →
±8.3%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, American Robin in Iowa is projected to stay roughly flat through 2030, near 89 (95% range 78–100). A 5-year backtest shows a typical error of ±8.3%, 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 →
2026857496
2027867597
2028877698
2029887799
20308978100

American Robin Survey Routes in Iowa

Routes recording American Robin 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 →
Panther27920251967
Mt Hamill12320251967
Mccallsburg11320251996
Red Rock10520251968
Sioux City10520251968
Hudson9720251967
Davis Corner9720251968
College Spgs 29720252005
Bryant9620251967
Washta9620251967
Neola9420251968
Festina9120251968
West Liberty9020251968
Scranton9020251967
Washington8820251967
Rock Valley8620251968
Pierson8120251968
Lafayette8120252003
Tipton7920251993
Cedar Valley7819971967
College Spgs7120041967
Wales7120251967
Gaza7020251969
Kanawha6420251967
Prairieburg6220251967

American Robin Population Trend in Other States

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

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