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

Seaside Sparrow In New England / Mid-Atlantic Coast

All regionsNew England / Mid-Atlantic CoastWetland birds

Seaside Sparrow in New England / Mid-Atlantic Coast has surged: up 130% on the route-weighted index since 1968.

+130%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 →
21Routes 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 →

long arc increasecomputed 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 →

Seaside Sparrow has surged in New England / Mid-Atlantic Coast: up 130% on the route-weighted index since 1968.

Seaside Sparrow In New England / Mid-Atlantic Coast Population Forecast

If the recent trend holds, Seaside Sparrow in New England / Mid-Atlantic Coast is projected to rise about 22% by 2030 — from 0.62 in 2025 to a central estimate of 0.76 (95% range 0.46–1.1). A 5-year backtest shows a typical error of ±31.4%, with 100% of held-out values landing inside the 95% band.

+22%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 →
0.76Projected 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 →
0.46–1.195% 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 →
±31.4%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, Seaside Sparrow in New England / Mid-Atlantic Coast is projected to rise about 22% by 2030 — from 0.62 in 2025 to a central estimate of 0.76 (95% range 0.46–1.1). A 5-year backtest shows a typical error of ±31.4%, 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 →
20260.730.431.0
20270.730.431.0
20280.740.441.0
20290.750.451.0
20300.760.461.1

Routes In New England / Mid-Atlantic Coast

Routes recording Seaside Sparrow 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 →
HarringtonDELAWARE192025
MadisonMARYLAND132025
HongaMARYLAND92025
DoverDELAWARE31985
Lowes XrdsDELAWARE31987
MiltonDELAWARE21975
GeorgetownDELAWARE22021
Milton 2DELAWARE22025
WesthamptonNEW-YORK21993
Jones BeachNEW-YORK21967
Bethany BchDELAWARE11990
BlackbirdDELAWARE12025
PepperboxDELAWARE12006
Pepperbox 2DELAWARE12025
CokesburyMARYLAND12025
NewburyportMASSACHUSETTS11994
Six PointsNEW-JERSEY12022
Ocean CityNEW-JERSEY12016
QuinbyVIRGINIA12012
GloucesterVIRGINIA12011
Chincoteag WVIRGINIA12024

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