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

Northern Rough-winged Swallow Population Trend in North Carolina

All statesAerial insectivores

Northern Rough-winged Swallow in North Carolina has risen sharply: up 53% on the route-weighted index since 1968.

+53%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 →
99Routes 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 Northern Rough-winged Swallow Trends in North 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 increasecomputed 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 →

Northern Rough-winged Swallow has risen sharply in North Carolina: up 53% on the route-weighted index since 1968.

Northern Rough-winged Swallow Population Forecast in North Carolina

If the recent trend holds, Northern Rough-winged Swallow in North Carolina is projected to rise about 12% by 2029 — from 0.91 in 2024 to a central estimate of 1.0 (95% range 0.00–2.7). A 5-year backtest shows a typical error of ±23.7%, with 100% of held-out values landing inside the 95% band.

+12%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 →
1.0Projected 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 →
0.00–2.795% 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 →
±23.7%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, Northern Rough-winged Swallow in North Carolina is projected to rise about 12% by 2029 — from 0.91 in 2024 to a central estimate of 1.0 (95% range 0.00–2.7). A 5-year backtest shows a typical error of ±23.7%, 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 →
20251.10.002.7
20261.10.002.7
20271.00.002.7
20281.00.002.7
20291.00.002.7

Northern Rough-winged Swallow Survey Routes in North Carolina

Routes recording Northern Rough-winged Swallow in North 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 →
Siloam1320172005
Copeland1220241968
Jonas Ridge1019711968
Jordan720221978
Mashoes619711971
Arcola620241971
Cullowhee620241974
California 2620232014
Hamlet620241995
Fairmont519811969
Rose519961979
Call520241969
Pinetops520222007
Goldston520192001
Climax420231966
Brevard420241968
Fontana420181972
Maple Hill420212006
South. Pines419961996
Mount Airy420232006
Mooresville320011967
Linville320221979
Sawmill320241990
Newport320212008
Wilgrove320172001

Northern Rough-winged Swallow Population Trend in Other States

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

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