BirdAnalyst
Species · BCR 14 · BBS 2026 Release · 1966–2025

Northern Rough-winged Swallow In Atlantic Northern Forest

All regionsAtlantic Northern ForestAerial insectivores

Northern Rough-winged Swallow in Atlantic Northern Forest has fallen sharply: down 52% on the route-weighted index since 1968.

-52%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 →
88Routes 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 →

Northern Rough-winged Swallow has fallen sharply in Atlantic Northern Forest: down 52% on the route-weighted index since 1968.

Northern Rough-winged Swallow In Atlantic Northern Forest Population Forecast

If the recent trend holds, Northern Rough-winged Swallow in Atlantic Northern Forest is projected to fall about 52% by 2030 — from 0.08 in 2025 to a central estimate of 0.04 (95% range 0.00–0.28). A 5-year backtest shows a typical error of ±37.1%, with 100% of held-out values landing inside the 95% band.

-52%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 →
0.04Projected 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 →
0.00–0.2895% 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 →
±37.1%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, Northern Rough-winged Swallow in Atlantic Northern Forest is projected to fall about 52% by 2030 — from 0.08 in 2025 to a central estimate of 0.04 (95% range 0.00–0.28). A 5-year backtest shows a typical error of ±37.1%, 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 →
20260.060.000.30
20270.050.000.30
20280.050.000.29
20290.040.000.29
20300.040.000.28

Routes In Atlantic Northern Forest

Routes recording Northern Rough-winged Swallow in Atlantic Northern Forest.
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 →
BentonMAINE171972
GlenNEW-HAMPSHIRE82010
ClarksvilleNEW-HAMPSHIRE72015
MiddlesexVERMONT71986
KasoagNEW-YORK62010
Moose RiverMAINE41994
CummingtonMASSACHUSETTS42009
PittsfieldMASSACHUSETTS42016
FitzwilliamNEW-HAMPSHIRE42025
HighmarketNEW-YORK42016
Blue Ridge NNEW-YORK41984
S WallingfrdVERMONT42017
StoweVERMONT41995
New HartfordCONNECTICUT32006
SheffieldMASSACHUSETTS32013
StratfordNEW-HAMPSHIRE32018
W RutlandVERMONT32022
BethelMAINE22006
East TroyMAINE22021
HermonMAINE21987
HudsonMAINE21989
Church HillMAINE22013
N OrangeMASSACHUSETTS21979
CheshireMASSACHUSETTS21993
HancockMASSACHUSETTS22000

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