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

Barn Swallow In New England / Mid-Atlantic Coast

All regionsNew England / Mid-Atlantic CoastAerial insectivores

Barn Swallow in New England / Mid-Atlantic Coast has declined: down 35% on the route-weighted index since 1968.

-35%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 →
163Routes 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 Barn Swallow in New England / Mid-Atlantic Coast. See the full index history below.

Barn Swallow In New England / Mid-Atlantic Coast Population Forecast

If the recent trend holds, Barn Swallow in New England / Mid-Atlantic Coast is projected to stay roughly flat through 2029, near 11 (95% range 7.6–14). A 5-year backtest shows a typical error of ±8.1%, with 100% of held-out values landing inside the 95% band.

-2%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 →
11Projected 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 →
7.6–1495% 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 →
±8.1%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, Barn Swallow in New England / Mid-Atlantic Coast is projected to stay roughly flat through 2029, near 11 (95% range 7.6–14). A 5-year backtest shows a typical error of ±8.1%, 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 →
2025117.915
2026117.815
2027117.714
2028117.614
2029117.614

Routes In New England / Mid-Atlantic Coast

Routes recording Barn Swallow 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 →
HarmonyMARYLAND982017
CokesburyMARYLAND852024
HarringtonDELAWARE622024
Snow HillMARYLAND491976
MysticCONNECTICUT452023
Bethany BchDELAWARE441990
BlackbirdDELAWARE442024
FredericaDELAWARE432014
DoverDELAWARE381987
FrankfordDELAWARE372012
ClarksvilleNEW-JERSEY371991
MardelaMARYLAND352019
DeepwaterNEW-JERSEY351977
SinepuxentMARYLAND331978
MillsboroDELAWARE322024
Ocean CityNEW-JERSEY322024
QuinbyVIRGINIA322024
WestbrookCONNECTICUT312024
Holleyville 2DELAWARE312024
UncasvilleCONNECTICUT302024
HolleyvilleDELAWARE272004
MiltonDELAWARE262016
Pedricktown 2NEW-JERSEY262024
KeyportNEW-JERSEY252022
Cape May ChNEW-JERSEY242013

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