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

Chimney Swift Population Trend in North Carolina

All statesAerial insectivores

Chimney Swift in North Carolina has fallen sharply: down 59% on the route-weighted index since 1968.

-59%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 →
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 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 59% 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 rise about 10% by 2029 — from 7.0 in 2024 to a central estimate of 7.8 (95% range 2.1–13). A 5-year backtest shows a typical error of ±17.6%, with 100% of held-out values landing inside the 95% band.

+10%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 →
7.8Projected 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 →
2.1–1395% 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 →
±17.6%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 rise about 10% by 2029 — from 7.0 in 2024 to a central estimate of 7.8 (95% range 2.1–13). A 5-year backtest shows a typical error of ±17.6%, 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 →
20258.52.914
20268.32.714
20278.22.514
20288.02.314
20297.82.113

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 →
Madison4019851966
Mooresville3920011966
Cherryville3919681968
Beargrass3319811966
Eden3220241987
Shallotte3119911966
Ostwalt3120242012
Oteen2220231976
Monticello2220241990
Speed2120241966
Jamesville2120241983
Flay2020241990
Copeland1820241968
Sawmill1820241990
Chowan River1720062002
Climax1620241966
Dortches1520241990
Gupton1420242001
Oakboro1320241969
Jackson1320171995
Siloam1320242005
Rheasville1320172005
Dismal Swamp1320171993
Craven Gap1219751969
Uwharrie Nf1220001993

Chimney Swift Population Trend in Other States

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

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