BirdAnalyst
Species · South Carolina · BBS 2026 Release · 1966–2025

Common Nighthawk Population Trend in South Carolina

All statesAerial insectivores

Common Nighthawk in South Carolina has fallen sharply: down 57% on the route-weighted index since 1968.

-57%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 →
28Routes 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 →
59YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Common Nighthawk 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 →

Common Nighthawk has fallen sharply in South Carolina: down 57% on the route-weighted index since 1968.

Common Nighthawk Population Forecast in South Carolina

If the recent trend holds, Common Nighthawk in South Carolina is projected to fall about 19% by 2030 — from 0.39 in 2025 to a central estimate of 0.32 (95% range 0.00–1.3). A 5-year backtest shows a typical error of ±65.8%, with 60% of held-out values landing inside the 95% band.

-19%Change by 2030TrendPercent 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 →
0.32Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–1.395% 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 →
±65.8%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, Common Nighthawk in South Carolina is projected to fall about 19% by 2030 — from 0.39 in 2025 to a central estimate of 0.32 (95% range 0.00–1.3). A 5-year backtest shows a typical error of ±65.8%, with 60% of held-out values landing inside the 95% band.19662030
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 →
20260.370.001.4
20270.360.001.3
20280.340.001.3
20290.330.001.3
20300.320.001.3

Common Nighthawk Survey Routes in South Carolina

Routes recording Common Nighthawk 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 →
Pendleton3219681968
Sandhills1120251994
Johns Isle219741966
Jamestown219961967
New Holland220231968
Green Sea220242021
Pinewood220092009
Hardeeville120081967
Rome120241967
Coward119871967
Foreston119791966
Wagener120171966
Kiawah Island120082008
Bishopville120181988
Walterboro119911970
Little Mtn119871986
Salem Xrd120112011
Boiling Spgs119761976
Plum Branch119811981
Nixonville119931993
New Ellenton120222022
Ridgeway120122012
Mount Pisgah119991998
Carvers Bay120101999
Nixville120141998

Common Nighthawk Population Trend in Other States

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

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.