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

Northern Rough-winged Swallow In New England / Mid-Atlantic Coast

All regionsNew England / Mid-Atlantic CoastAerial insectivores

Northern Rough-winged Swallow in New England / Mid-Atlantic Coast has edged up: up 22% on the route-weighted index since 1968.

+22%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 →
121Routes 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 Northern Rough-winged Swallow in New England / Mid-Atlantic Coast. See the full index history below.

Northern Rough-winged Swallow In New England / Mid-Atlantic Coast Population Forecast

If the recent trend holds, Northern Rough-winged Swallow in New England / Mid-Atlantic Coast is projected to stay roughly flat through 2029, near 0.50 (95% range 0.08–0.93). A 5-year backtest shows a typical error of ±51%, with 100% of held-out values landing inside the 95% band.

+3%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 →
0.50Projected 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 →
0.08–0.9395% 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 →
±51%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, Northern Rough-winged Swallow in New England / Mid-Atlantic Coast is projected to stay roughly flat through 2029, near 0.50 (95% range 0.08–0.93). A 5-year backtest shows a typical error of ±51%, 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 →
20250.500.070.93
20260.500.080.93
20270.500.080.93
20280.500.080.93
20290.500.080.93

Routes In New England / Mid-Atlantic Coast

Routes recording Northern Rough-winged 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 →
UncasvilleCONNECTICUT152024
MansfieldMASSACHUSETTS102024
ElktonMARYLAND62023
BuckinghamCONNECTICUT52022
DanburyCONNECTICUT52017
ShermanCONNECTICUT42019
Lowes XrdsDELAWARE41978
BeltsvilleMARYLAND42008
Forest GroveMARYLAND42023
E PepperellMASSACHUSETTS41992
Woodbury HgtNEW-JERSEY42021
PurdyNEW-YORK41991
QuinbyVIRGINIA41995
MysticCONNECTICUT32013
Mid HaddamCONNECTICUT32024
LargoMARYLAND31966
IndiantownMARYLAND32010
Fair HillMARYLAND31996
Ware RiverMASSACHUSETTS32005
GloucesterVIRGINIA32012
TruhartVIRGINIA32015
WestbrookCONNECTICUT22024
SouthingtonCONNECTICUT22017
Warren 2CONNECTICUT22022
Mt PleasantDELAWARE22006

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