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

Long-billed Curlew Population Trend in South Dakota

All statesShorebirds

Long-billed Curlew in South Dakota has risen sharply: up 70% on the route-weighted index since 1969.

+70%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 →
27Routes 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 Long-billed Curlew 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 →

Long-billed Curlew has risen sharply in South Dakota: up 70% on the route-weighted index since 1969.

Long-billed Curlew Population Forecast in South Dakota

If the recent trend holds, Long-billed Curlew in South Dakota is projected to fall about 16% by 2029 — from 1.5 in 2024 to a central estimate of 1.2 (95% range 0.49–2.0). A 5-year backtest shows a typical error of ±91.3%, with 80% of held-out values landing inside the 95% band.

-16%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 →
1.2Projected 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 →
0.49–2.095% 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 →
±91.3%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, Long-billed Curlew in South Dakota is projected to fall about 16% by 2029 — from 1.5 in 2024 to a central estimate of 1.2 (95% range 0.49–2.0). A 5-year backtest shows a typical error of ±91.3%, with 80% 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 →
20251.20.461.9
20261.20.471.9
20271.20.471.9
20281.20.481.9
20291.20.492.0

Long-billed Curlew Survey Routes in South Dakota

Routes recording Long-billed Curlew 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 →
S. Pioneer1320241994
Pioneer920241992
Cedar Pass620171967
Rosebud420111967
Hayes420241992
French Creek320051998
Owanka319961967
Ardmore320191977
Badlands320231983
White River320122012
Cottonwood220241995
Indian220241994
Railroad Butte220181997
Volunteer220171967
Fort Pierre220241969
Maurine219711969
Eagle Butte220152001
Marcus220131999
Winner120092009
Rockyford120062006
Wind Cave Np120132005
Laplant120091977
Promise119991987
Ottumwa120221967
Harding120171967

Long-billed Curlew Population Trend in Other States

californiacoloradoidahokansasmontananebraskanevadanew-mexiconorth-dakotaoklahomaoregontexasutahwashingtonwyoming

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