BirdAnalyst
Species · BCR 28 · BBS 2026 Release · 1966–2025

Chimney Swift In Appalachian Mountains

All regionsAppalachian MountainsAerial insectivores

Chimney Swift in Appalachian Mountains has fallen sharply: down 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 →
397Routes In RegionSurvey 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 SignalsNotable 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 Appalachian Mountains: down 53% on the route-weighted index since 1968.

Chimney Swift In Appalachian Mountains Population Forecast

If the recent trend holds, Chimney Swift in Appalachian Mountains is projected to fall about 17% by 2030 — from 5.7 in 2025 to a central estimate of 4.7 (95% range 2.0–7.4). A 5-year backtest shows a typical error of ±6.5%, with 100% of held-out values landing inside the 95% band.

-17%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 →
4.7Projected 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 →
2.0–7.495% 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 →
±6.5%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 Appalachian Mountains is projected to fall about 17% by 2030 — from 5.7 in 2025 to a central estimate of 4.7 (95% range 2.0–7.4). A 5-year backtest shows a typical error of ±6.5%, 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 →
20265.22.57.9
20275.12.47.8
20285.02.37.6
20294.82.27.5
20304.72.07.4

Routes In Appalachian Mountains

Routes recording Chimney Swift in Appalachian Mountains.
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 →
BirminghamALABAMA1451995
WilliamsportMARYLAND522025
ClimerTENNESSEE522004
RydePENNSYLVANIA472005
DearmanvilleALABAMA451983
Corryton RdTENNESSEE442019
McdonaldWEST-VIRGINIA422023
Coal RunOHIO411992
PortersvillePENNSYLVANIA401988
KittanningPENNSYLVANIA402025
HopeNEW-JERSEY391994
SmithfieldOHIO382025
BloomsburyNEW-JERSEY362025
BeaverPENNSYLVANIA362025
ParkwoodPENNSYLVANIA362025
ArleeWEST-VIRGINIA361979
NewcomerstwnOHIO351995
GreensportALABAMA332025
N WashingtonPENNSYLVANIA322025
WakenaPENNSYLVANIA322023
Bald EaglePENNSYLVANIA322025
PattonPENNSYLVANIA312024
MidvaleNEW-JERSEY292022
StanleyVIRGINIA292025
FayettevilleWEST-VIRGINIA281996

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