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

Great Black-backed Gull In New England / Mid-Atlantic Coast

All regionsNew England / Mid-Atlantic CoastWetland birds

Great Black-backed Gull in New England / Mid-Atlantic Coast has surged: up 159% on the route-weighted index since 1968.

+159%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 →
55Routes 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 →

Great Black-backed Gull has surged in New England / Mid-Atlantic Coast: up 159% on the route-weighted index since 1968.

Great Black-backed Gull In New England / Mid-Atlantic Coast Population Forecast

If the recent trend holds, Great Black-backed Gull in New England / Mid-Atlantic Coast is projected to fall about 26% by 2030 — from 1.4 in 2025 to a central estimate of 1.0 (95% range 0.09–1.9). A 5-year backtest shows a typical error of ±131.1%, with 100% of held-out values landing inside the 95% band.

-26%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 →
1.0Projected 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 →
0.09–1.995% 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 →
±131.1%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, Great Black-backed Gull in New England / Mid-Atlantic Coast is projected to fall about 26% by 2030 — from 1.4 in 2025 to a central estimate of 1.0 (95% range 0.09–1.9). A 5-year backtest shows a typical error of ±131.1%, 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 →
20260.980.051.9
20270.990.061.9
20280.990.071.9
20291.00.081.9
20301.00.091.9

Routes In New England / Mid-Atlantic Coast

Routes recording Great Black-backed Gull 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 →
Block IslandRHODE-ISLAND892025
Sachuest PtRHODE-ISLAND231989
ChilmarkMASSACHUSETTS221983
WesthamptonNEW-YORK132018
Cape May ChNEW-JERSEY82011
Jones BeachNEW-YORK72013
Ocean CityNEW-JERSEY62025
BerlinMARYLAND42005
Gay HeadMASSACHUSETTS42023
Six PointsNEW-JERSEY42025
Bethany BchDELAWARE31990
MiltonDELAWARE31977
MelitotaMARYLAND32004
E PepperellMASSACHUSETTS31989
BrentwoodNEW-HAMPSHIRE31983
EpsomNEW-HAMPSHIRE31989
Del HavenNEW-JERSEY31991
HuntingtonNEW-YORK32023
MysticCONNECTICUT22023
HarringtonDELAWARE22017
PepperboxDELAWARE22005
Kittery PtMAINE22025
MatthewsMARYLAND22001
NewarkMARYLAND22024
SinepuxentMARYLAND21974

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