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

American Robin Population Trend in Iowa

All statesForest birds

American Robin in Iowa has surged: up 155% on the route-weighted index since 1969.

+155%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 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 155% 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 2029, near 88 (95% range 77–100). A 5-year backtest shows a typical error of ±9.3%, with 100% of held-out values landing inside the 95% band.

+5%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 →
88Projected 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 →
77–10095% 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 →
±9.3%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 2029, near 88 (95% range 77–100). A 5-year backtest shows a typical error of ±9.3%, 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 →
2025847396
2026857497
2027867598
2028877699
20298877100

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 →
Panther31420241967
Red Rock14620241968
Mccallsburg12820241996
West Liberty11720241968
Lafayette9720242003
Sioux City9420241968
Bryant8820241967
Neola8620161968
Washington8520241967
Mt Hamill8420241967
Brooklyn8420221967
Scranton8420241967
Cedar Valley7819971967
College Spgs 27820232005
Washta7520141967
Gaza7420231969
Titonka7320241968
Tipton7220241993
College Spgs7120041967
Davis Corner6620241968
Rock Valley6520241968
Kanawha5820241967
Festina5720241968
Clare5620191967
Burchinal5420241995

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 2026-05-22.