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

Red-winged Blackbird Population Trend in South Carolina

All statesGeneralists

Red-winged Blackbird in South Carolina has collapsed: down 94% on the route-weighted index since 1968.

-94%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 →
48Routes 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 Red-winged Blackbird 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 →

Red-winged Blackbird has collapsed in South Carolina: down 94% on the route-weighted index since 1968.

Red-winged Blackbird Population Forecast in South Carolina

If the recent trend holds, Red-winged Blackbird in South Carolina is projected to fall about 100% by 2029 — from 1.6 in 2024 to a central estimate of 0.00 (95% range 0.00–13). A 5-year backtest shows a typical error of ±409.1%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–1395% 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 →
±409.1%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, Red-winged Blackbird in South Carolina is projected to fall about 100% by 2029 — from 1.6 in 2024 to a central estimate of 0.00 (95% range 0.00–13). A 5-year backtest shows a typical error of ±409.1%, 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 →
20250.000.0013
20260.000.0013
20270.000.0013
20280.000.0013
20290.000.0013

Red-winged Blackbird Survey Routes in South Carolina

Routes recording Red-winged Blackbird 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 →
Boykin Ml Pd6419681967
Dillon6020211970
Pendleton5019761966
Johns Isle4519791966
Adams Run2020222000
Kiawah Island1920241998
Ward1820212017
Boiling Spgs1619791967
Foreston820211966
Bennettsville820171998
Nixonville719951987
Little Mtn619881966
Green Sea620242010
Landrum519921972
Anderson420131977
Barton Creek320221967
Campobello320212010
Olar320071998
Pinewood320141998
Carvers Bay320121999
Prosperity320041992
Coward220211966
Bishopville220241970
Plum Branch220211977
New Ellenton220242018

Red-winged Blackbird Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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