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Species · South Carolina · BBS 2025 Release · 1966–2024

Grasshopper Sparrow Population Trend in South Carolina

All statesGrassland birds

Grasshopper Sparrow in South Carolina has fallen sharply: down 69% on the route-weighted index since 1968.

-69%Since 1968TrendPercent 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 →
24Routes 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 Grasshopper Sparrow Trends in South CarolinaNotable 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 →

Grasshopper Sparrow has fallen sharply in South Carolina: down 69% on the route-weighted index since 1968.

Grasshopper Sparrow Population Forecast in South Carolina

If the recent trend holds, Grasshopper Sparrow in South Carolina is projected to rise about 84% by 2029 — from 0.43 in 2024 to a central estimate of 0.79 (95% range 0.00–2.3). A 5-year backtest shows a typical error of ±300.2%, with 100% of held-out values landing inside the 95% band.

+84%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 →
0.79Projected 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 →
0.00–2.395% 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 →
±300.2%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, Grasshopper Sparrow in South Carolina is projected to rise about 84% by 2029 — from 0.43 in 2024 to a central estimate of 0.79 (95% range 0.00–2.3). A 5-year backtest shows a typical error of ±300.2%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20250.820.002.3
20260.810.002.3
20270.800.002.3
20280.800.002.3
20290.790.002.3

Grasshopper Sparrow Survey Routes in South Carolina

Routes recording Grasshopper Sparrow in South Carolina.
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 →
Pendleton1519761966
Campobello920242010
Owings620041992
Landrum319921972
Prosperity320061997
Chesnee320151992
Wagener219791979
Battlecreek220142000
Cauthens Xrd220081982
New Holland119921987
Dillon120211992
Little Mtn119811966
Salem Xrd120171986
Barton Creek120101967
Boiling Spgs119791967
Ward120182018
Whitmire120102010
Blacksburg120121998
Joanna120231999
Mount Pisgah119991998
Bennettsville120001998
Olar119981998
Anderson120171977
Owings 2120082005

Grasshopper Sparrow Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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