BirdAnalyst
Species · BCR 30 · BBS 2026 Release · 1966–2025

Tree Swallow In New England / Mid-Atlantic Coast

All regionsNew England / Mid-Atlantic CoastAerial insectivores

Tree Swallow in New England / Mid-Atlantic Coast has edged up: up 17% on the route-weighted index since 1968.

+17%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 →
153Routes 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 →
59YearsYears 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 Tree Swallow in New England / Mid-Atlantic Coast. See the full index history below.

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

If the recent trend holds, Tree Swallow in New England / Mid-Atlantic Coast is projected to rise about 19% by 2030 — from 3.6 in 2025 to a central estimate of 4.3 (95% range 2.9–5.6). A 5-year backtest shows a typical error of ±14.3%, with 100% of held-out values landing inside the 95% band.

+19%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 →
4.3Projected 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 →
2.9–5.695% 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 →
±14.3%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, Tree Swallow in New England / Mid-Atlantic Coast is projected to rise about 19% by 2030 — from 3.6 in 2025 to a central estimate of 4.3 (95% range 2.9–5.6). A 5-year backtest shows a typical error of ±14.3%, 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 →
20264.22.85.5
20274.22.85.5
20284.22.95.6
20294.32.95.6
20304.32.95.6

Routes In New England / Mid-Atlantic Coast

Routes recording Tree 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 →
MadisonMARYLAND402025
WilmingtonDELAWARE182014
BlackbirdDELAWARE182025
GeorgetownDELAWARE182022
JessupMARYLAND172025
Warren 2MASSACHUSETTS162025
WarrenCONNECTICUT132011
HongaMARYLAND132025
Cape CharlesVIRGINIA132018
MansfieldMASSACHUSETTS122024
PomonaNEW-JERSEY122025
BrentwoodNEW-HAMPSHIRE111997
Jones BeachNEW-YORK112013
FredericaDELAWARE102014
Milton 2DELAWARE102025
BrocktonMASSACHUSETTS102019
BelchertownMASSACHUSETTS102025
ShermanCONNECTICUT92019
Woodstock 2CONNECTICUT92025
S BarreMASSACHUSETTS92025
HarringtonDELAWARE82025
N. AndoverMASSACHUSETTS82025
EpsomNEW-HAMPSHIRE82025
WoodstockCONNECTICUT72007
PrincetonMASSACHUSETTS71976

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