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

Brown Thrasher Population Trend in South Carolina

All statesGeneralists

Brown Thrasher in South Carolina has declined: down 46% on the route-weighted index since 1968.

-46%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 →
51Routes 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 →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Brown Thrasher 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 →

No notable trend signals for Brown Thrasher in South Carolina. See the full index history below.

Brown Thrasher Population Forecast in South Carolina

If the recent trend holds, Brown Thrasher in South Carolina is projected to stay roughly flat through 2029, near 6.0 (95% range 3.3–8.7). A 5-year backtest shows a typical error of ±31.4%, with 100% of held-out values landing inside the 95% band.

+3%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 →
6.0Projected 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 →
3.3–8.795% 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 →
±31.4%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, Brown Thrasher in South Carolina is projected to stay roughly flat through 2029, near 6.0 (95% range 3.3–8.7). A 5-year backtest shows a typical error of ±31.4%, 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 →
20256.13.48.7
20266.03.38.7
20276.03.38.7
20286.03.38.7
20296.03.38.7

Brown Thrasher Survey Routes in South Carolina

Routes recording Brown Thrasher 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 →
Owings2120041992
Chesnee1620151992
Campobello1520242010
Holly Hill1320241972
Boykin Ml Pd1019681966
Walterboro1020171970
Salem Xrd1020191982
Boiling Spgs1019791967
Green Sea1020242010
Salem1020242010
Rome920241967
Sandhills920241994
Landrum819921972
Blacksburg820131999
Owings 2820242005
Bishopville720241970
Lowrys720212017
Pinewood720191998
Coward620241966
New Holland620241967
Pendleton619761966
Barton Creek620221967
Johns Isle519791966
Little Mtn519881966
Foreston420211966

Brown Thrasher Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

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