BirdAnalyst
Species · BCR 30 · BBS 2025 Release · 1966–2024

Chimney Swift In New England / Mid-Atlantic Coast

All regionsNew England / Mid-Atlantic CoastAerial insectivores

Chimney Swift in New England / Mid-Atlantic Coast has declined: down 40% on the route-weighted index since 1968.

-40%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 →
161Routes 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 →

No notable trend signals for Chimney Swift in New England / Mid-Atlantic Coast. See the full index history below.

Chimney Swift In New England / Mid-Atlantic Coast Population Forecast

If the recent trend holds, Chimney Swift in New England / Mid-Atlantic Coast is projected to fall about 16% by 2029 — from 7.1 in 2024 to a central estimate of 6.0 (95% range 3.4–8.5). A 5-year backtest shows a typical error of ±9.2%, with 100% of held-out values landing inside the 95% band.

-16%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 →
6.0Projected 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 →
3.4–8.595% 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 →
±9.2%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 New England / Mid-Atlantic Coast is projected to fall about 16% by 2029 — from 7.1 in 2024 to a central estimate of 6.0 (95% range 3.4–8.5). A 5-year backtest shows a typical error of ±9.2%, 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 →
20256.33.78.8
20266.23.68.8
20276.13.58.7
20286.03.58.6
20296.03.48.5

Routes In New England / Mid-Atlantic Coast

Routes recording Chimney Swift in New England / Mid-Atlantic Coast.
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 →
JonesMARYLAND551994
Wallum LakeRHODE-ISLAND532024
Kittery PtMAINE502024
DeepwaterNEW-JERSEY431977
LargoMARYLAND421981
HarmonyMARYLAND422017
Island CreekMARYLAND362024
Snow HillMARYLAND351976
Del HavenNEW-JERSEY311991
E PepperellMASSACHUSETTS271994
PedricktownNEW-JERSEY272012
BeltsvilleMARYLAND252012
DoverDELAWARE231987
DoverNEW-HAMPSHIRE222024
Lowes XrdsDELAWARE201991
Forest GroveMARYLAND192023
Warren 2MASSACHUSETTS192024
GreenwichNEW-JERSEY192024
PrattvilleMASSACHUSETTS182019
WarrenMASSACHUSETTS182009
Cape May ChNEW-JERSEY182013
WillimanticCONNECTICUT172018
HarringtonDELAWARE162024
Casimir Pulaski SfRHODE-ISLAND162018
E HartlandCONNECTICUT151992

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