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

Chimney Swift Population Trend in North Carolina

All statesAerial insectivores

Chimney Swift in North Carolina has fallen sharply: down 61% on the route-weighted index since 1968.

-61%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 →
111Routes 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 Chimney Swift 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 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 →

Chimney Swift has fallen sharply in North Carolina: down 61% on the route-weighted index since 1968.

Chimney Swift Population Forecast in North Carolina

If the recent trend holds, Chimney Swift in North Carolina is projected to stay roughly flat through 2030, near 7.5 (95% range 1.9–13). A 5-year backtest shows a typical error of ±19.3%, with 100% of held-out values landing inside the 95% band.

+1%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 →
7.5Projected 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 →
1.9–1395% 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 →
±19.3%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, Chimney Swift in North Carolina is projected to stay roughly flat through 2030, near 7.5 (95% range 1.9–13). A 5-year backtest shows a typical error of ±19.3%, with 100% 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 →
20268.32.614
20278.12.414
20287.92.214
20297.72.013
20307.51.913

Chimney Swift Survey Routes in North Carolina

Routes recording Chimney Swift 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 →
Speed7620251966
Madison4019851966
Mooresville3920011966
Cherryville3919681968
Beargrass3319811966
Shallotte3119911966
Oteen2220231976
Jamesville2120251983
Copeland1920251968
Monticello1820251990
Siloam1820252005
California 21720252014
Eden1720251987
Sheffield1720251991
Flay1720251990
Dortches1720251990
Chowan River1720062002
Gupton1520252001
Call1420251968
Mooresville 21420252006
Sawmill1420251990
Ostwalt1420252012
Jackson1320171995
Rheasville1320172005
Dismal Swamp1320171993

Chimney Swift Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

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