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

Bachman's Sparrow Population Trend in South Carolina

All statesGeneralists

Bachman's Sparrow in South Carolina has fallen sharply: down 65% on the route-weighted index since 1969.

-65%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 →
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 →
55YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Bachman's 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 →

Bachman's Sparrow has fallen sharply in South Carolina: down 65% on the route-weighted index since 1969.

Bachman's Sparrow Population Forecast in South Carolina

If the recent trend holds, Bachman's Sparrow in South Carolina is projected to fall about 48% by 2029 — from 0.43 in 2024 to a central estimate of 0.23 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±225.1%, with 100% of held-out values landing inside the 95% band.

-48%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 →
0.23Projected 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 →
0.00–1.195% 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 →
±225.1%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, Bachman's Sparrow in South Carolina is projected to fall about 48% by 2029 — from 0.43 in 2024 to a central estimate of 0.23 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±225.1%, 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 →
20250.260.001.1
20260.250.001.1
20270.240.001.1
20280.230.001.1
20290.230.001.1

Bachman's Sparrow Survey Routes in South Carolina

Routes recording Bachman's 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 →
Sandhills920241994
Olar520191998
Pendleton219701970
Plum Branch219921979
Pinewood220141998
Dale220222017
Johns Isle119731966
Jamestown120171967
Hardeeville120231988
Rome120001982
Coward119911977
Foreston119761966
New Holland120181971
Wagener120071980
Bishopville119841984
Boykin Ml Pd119671967
Walterboro119791979
Little Mtn119851967
Salem Xrd120051984
Landrum119871987
Mount Pisgah120001998
Nixville120131998
Adams Run120171988
Cauthens Xrd119851984

Bachman's Sparrow Population Trend in Other States

alabamaarkansasfloridageorgiakentuckylouisianamississippimissourinorth-carolinaohiooklahomatennesseetexasvirginia

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