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

Forster's Tern In New England / Mid-Atlantic Coast

All regionsNew England / Mid-Atlantic CoastWetland birds

Forster's Tern in New England / Mid-Atlantic Coast has surged: up 276% on the route-weighted index since 1968.

+276%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 →
31Routes 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 →
55YearsYears 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 →

Forster's Tern has surged in New England / Mid-Atlantic Coast: up 276% on the route-weighted index since 1968.

Forster's Tern In New England / Mid-Atlantic Coast Population Forecast

If the recent trend holds, Forster's Tern in New England / Mid-Atlantic Coast is projected to rise about 138% by 2029 — from 0.18 in 2024 to a central estimate of 0.44 (95% range 0.09–0.78). A 5-year backtest shows a typical error of ±223.1%, with 80% of held-out values landing inside the 95% band.

+138%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 →
0.44Projected 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 →
0.09–0.7895% 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 →
±223.1%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, Forster's Tern in New England / Mid-Atlantic Coast is projected to rise about 138% by 2029 — from 0.18 in 2024 to a central estimate of 0.44 (95% range 0.09–0.78). A 5-year backtest shows a typical error of ±223.1%, with 80% 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 →
20250.410.070.76
20260.420.080.77
20270.430.080.77
20280.430.090.78
20290.440.090.78

Routes In New England / Mid-Atlantic Coast

Routes recording Forster's Tern 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 →
Del HavenNEW-JERSEY111991
Ocean CityNEW-JERSEY82024
Six PointsNEW-JERSEY72014
Cape May ChNEW-JERSEY72013
White StoneVIRGINIA71996
Pepperbox 2DELAWARE52024
Golden HillMARYLAND52006
Bethany BchDELAWARE41989
PepperboxDELAWARE42016
VillasNEW-JERSEY41981
HuntingtonNEW-YORK42023
SharpsVIRGINIA41999
QuinbyVIRGINIA31983
Lowes XrdsDELAWARE21991
PomfretMARYLAND21974
EastonMARYLAND22013
MadisonMARYLAND22021
FruitlandMARYLAND21985
CokesburyMARYLAND22015
NewarkMARYLAND22018
WinslowNEW-JERSEY22000
HarringtonDELAWARE12023
DoverDELAWARE11966
FrankfordDELAWARE12006
BlackbirdDELAWARE12024

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