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

Least Tern In New England / Mid-Atlantic Coast

All regionsNew England / Mid-Atlantic CoastWetland birds

Least Tern in New England / Mid-Atlantic Coast has declined: down 45% on the route-weighted index since 1968.

-45%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 →
32Routes 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 →

No notable trend signals for Least Tern in New England / Mid-Atlantic Coast. See the full index history below.

Least Tern In New England / Mid-Atlantic Coast Population Forecast

If the recent trend holds, Least Tern in New England / Mid-Atlantic Coast is projected to fall about 100% by 2030 — from 0.18 in 2025 to a central estimate of 0.00 (95% range 0.00–0.53). A 5-year backtest shows a typical error of ±366.1%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–0.5395% 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 →
±366.1%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, Least Tern in New England / Mid-Atlantic Coast is projected to fall about 100% by 2030 — from 0.18 in 2025 to a central estimate of 0.00 (95% range 0.00–0.53). A 5-year backtest shows a typical error of ±366.1%, 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 →
20260.000.000.53
20270.000.000.53
20280.000.000.53
20290.000.000.53
20300.000.000.53

Routes In New England / Mid-Atlantic Coast

Routes recording Least 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 →
Bethany BchDELAWARE211990
Gay HeadMASSACHUSETTS212024
Lowes XrdsDELAWARE201987
EastonMARYLAND82025
Wellfleet 2MASSACHUSETTS82023
HuntingtonNEW-YORK72011
Golden HillMARYLAND61995
ChilmarkMASSACHUSETTS41983
BlackbirdDELAWARE31998
HongaMARYLAND32025
NewburyportMASSACHUSETTS31997
Jones BeachNEW-YORK32006
HarringtonDELAWARE22025
DoverDELAWARE21974
MiltonDELAWARE21971
Kittery PtMAINE22018
E DennisMASSACHUSETTS22000
Toms RiverNEW-JERSEY21975
VillasNEW-JERSEY21981
Cape May ChNEW-JERSEY21992
White StoneVIRGINIA21996
GeorgetownDELAWARE11994
NortheastMARYLAND12004
ElktonMARYLAND12012
MillingtonMARYLAND12009

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