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

Spotted Sandpiper Population Trend in Iowa

All statesShorebirds

Spotted Sandpiper in Iowa has surged: up 176% on the route-weighted index since 1970.

+176%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 →
30Routes 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 →
37YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Spotted Sandpiper 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 →

Spotted Sandpiper has surged in Iowa: up 176% on the route-weighted index since 1970.

Spotted Sandpiper Population Forecast in Iowa

If the recent trend holds, Spotted Sandpiper in Iowa is projected to fall about 37% by 2029 — from 0.18 in 2024 to a central estimate of 0.11 (95% range 0.02–0.21). A 5-year backtest shows a typical error of ±47.1%, with 100% of held-out values landing inside the 95% band.

-37%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 →
0.11Projected 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 →
0.02–0.2195% 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 →
±47.1%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, Spotted Sandpiper in Iowa is projected to fall about 37% by 2029 — from 0.18 in 2024 to a central estimate of 0.11 (95% range 0.02–0.21). A 5-year backtest shows a typical error of ±47.1%, 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 →
20250.110.020.20
20260.110.020.20
20270.110.020.20
20280.110.020.20
20290.110.020.21

Spotted Sandpiper Survey Routes in Iowa

Routes recording Spotted Sandpiper 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 →
Melrose220122002
Bryant220221974
Dinsdale219831983
Sioux City220241982
Bedford119691969
College Spgs119911991
West Liberty120241979
Cedar Valley119771977
Brooklyn119891974
Burchinal120232023
Red Rock119961996
Panther120151973
Washington120142014
Wales120031992
Prairieburg120151974
Hudson119831983
Kanawha120211991
Zearing119951992
Scranton119761975
Pierson120031995
Washta120102010
Festina120231968
Davis Corner120242024
Garner119811975
Titonka119961981

Spotted Sandpiper Population Trend in Other States

alabamaalaskaarizonacaliforniacoloradoconnecticutdelawaregeorgiaidahoillinoisindianakansaskentuckymainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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