BirdAnalyst
Species · South Dakota · BBS 2025 Release · 1966–2024

American Avocet Population Trend in South Dakota

All statesShorebirds

American Avocet in South Dakota has surged: up 128% on the route-weighted index since 1969.

+128%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 →
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 →
48YearsYears 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 Avocet Trends in South DakotaNotable 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 Avocet has surged in South Dakota: up 128% on the route-weighted index since 1969.

American Avocet Population Forecast in South Dakota

If the recent trend holds, American Avocet in South Dakota is projected to stay roughly flat through 2029, near 0.29 (95% range 0.00–0.89). A 5-year backtest shows a typical error of ±23.5%, with 100% of held-out values landing inside the 95% band.

+7%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 →
0.29Projected 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 →
0.00–0.8995% 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 →
±23.5%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 Avocet in South Dakota is projected to stay roughly flat through 2029, near 0.29 (95% range 0.00–0.89). A 5-year backtest shows a typical error of ±23.5%, 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 →
20250.300.000.89
20260.300.000.89
20270.290.000.89
20280.290.000.89
20290.290.000.89

American Avocet Survey Routes in South Dakota

Routes recording American Avocet in South Dakota.
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 →
Volunteer1419931980
Conde1119841984
Gettysburg920232019
S. Pioneer820122012
Veblen719841984
Cottonwood520241992
Raymond520182007
Long Lake520181967
Broadland420102000
White Lake319951968
Volga320222022
Britton319851985
Ottumwa320161987
Gorman320102001
Lacreek320191991
Pioneer220231992
Crow Creek220191967
Indian220052002
Railroad Butte220162005
Forbes220221978
Wind Cave Np220142014
Harding220161968
Cedar Pass220011977
Ardmore220111985
Chamberlain120102010

American Avocet Population Trend in Other States

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