BirdAnalyst
Species · BCR 29 · BBS 2025 Release · 1966–2024

Chimney Swift In Piedmont

All regionsPiedmontAerial insectivores

Chimney Swift in Piedmont has fallen sharply: down 58% on the route-weighted index since 1968.

-58%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 →
171Routes 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 →
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 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 Piedmont: down 58% on the route-weighted index since 1968.

Chimney Swift In Piedmont Population Forecast

If the recent trend holds, Chimney Swift in Piedmont is projected to stay roughly flat through 2029, near 8.5 (95% range 5.2–12). A 5-year backtest shows a typical error of ±20%, with 100% of held-out values landing inside the 95% band.

+7%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 →
8.5Projected 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 →
5.2–1295% 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 →
±20%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 Piedmont is projected to stay roughly flat through 2029, near 8.5 (95% range 5.2–12). A 5-year backtest shows a typical error of ±20%, 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 →
20259.26.012
20269.05.812
20278.95.612
20288.75.412
20298.55.212

Routes In Piedmont

Routes recording Chimney Swift in Piedmont.
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 →
West GrovePENNSYLVANIA541996
WheatonMARYLAND432024
EphrataPENNSYLVANIA421988
AspersPENNSYLVANIA421989
MadisonNORTH-CAROLINA401985
MooresvilleNORTH-CAROLINA392001
CherryvilleNORTH-CAROLINA391968
OwingsSOUTH-CAROLINA362004
JoannaSOUTH-CAROLINA332019
EdenNORTH-CAROLINA322024
OstwaltNORTH-CAROLINA312024
PendletonSOUTH-CAROLINA311976
FairplayGEORGIA301991
HiramGEORGIA282018
Mount JoyPENNSYLVANIA282024
EkloMARYLAND272018
IjamsvilleMARYLAND272024
Little MtnSOUTH-CAROLINA271988
Silver SpgMARYLAND251989
Sporting HilPENNSYLVANIA241977
Hollonville 2GEORGIA232022
MonticelloNORTH-CAROLINA222024
Great FallsVIRGINIA211976
FlayNORTH-CAROLINA202024
Salem XrdSOUTH-CAROLINA202019

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