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

Horned Lark Population Trend in South Dakota

All statesGrassland birds

Horned Lark in South Dakota has fallen sharply: down 72% on the route-weighted index since 1969.

-72%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 →
54Routes 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 Horned Lark 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 declinecomputed 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 →

Horned Lark has fallen sharply in South Dakota: down 72% on the route-weighted index since 1969.

Horned Lark Population Forecast in South Dakota

If the recent trend holds, Horned Lark in South Dakota is projected to fall about 20% by 2029 — from 8.4 in 2024 to a central estimate of 6.7 (95% range 0.00–26). A 5-year backtest shows a typical error of ±33.8%, with 100% of held-out values landing inside the 95% band.

-20%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 →
6.7Projected 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 →
0.00–2695% 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 →
±33.8%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, Horned Lark in South Dakota is projected to fall about 20% by 2029 — from 8.4 in 2024 to a central estimate of 6.7 (95% range 0.00–26). A 5-year backtest shows a typical error of ±33.8%, 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 →
20259.00.0028
20268.40.0027
20277.80.0027
20287.30.0026
20296.70.0026

Horned Lark Survey Routes in South Dakota

Routes recording Horned Lark 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 →
Conde21719841967
Gorman5420101979
Lodgepole4620241990
Eagle Butte4520151990
Owanka3420221967
French Creek3320051995
Gettysburg3020231969
Promise2920151971
Wilmot2820241967
Cedar Pass2420231967
Howard2020241970
Lacreek2020231991
Isabel1920151990
Badlands1820231982
Ottumwa1720221967
Ardmore1720191977
Railroad Butte1520221995
Cottonwood1420241992
S. Pioneer1420241994
Veblen1320231967
Raymond1120211967
Reva1120241979
Hayes1120241989
Crow Creek1020231967
Britton1020231967

Horned Lark Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawaregeorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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