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

Common Loon In New England / Mid-Atlantic Coast

All regionsNew England / Mid-Atlantic CoastWetland birds

Common Loon in New England / Mid-Atlantic Coast has surged: up 188% on the route-weighted index since 1973.

+188%Since 1973TrendPercent 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 →
8Routes 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 →
43YearsYears 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 →

Common Loon has surged in New England / Mid-Atlantic Coast: up 188% on the route-weighted index since 1973.

Common Loon In New England / Mid-Atlantic Coast Population Forecast

If the recent trend holds, Common Loon in New England / Mid-Atlantic Coast is projected to fall about 61% by 2029 — from 0.16 in 2024 to a central estimate of 0.06 (95% range 0.01–0.11). A 5-year backtest shows a typical error of ±105%, with 60% of held-out values landing inside the 95% band.

-61%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 →
0.06Projected 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 →
0.01–0.1195% 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 →
±105%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, Common Loon in New England / Mid-Atlantic Coast is projected to fall about 61% by 2029 — from 0.16 in 2024 to a central estimate of 0.06 (95% range 0.01–0.11). A 5-year backtest shows a typical error of ±105%, with 60% of held-out values landing inside the 95% band.19692029
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 →
20250.060.010.11
20260.060.010.11
20270.060.010.11
20280.060.010.11
20290.060.010.11

Routes In New England / Mid-Atlantic Coast

Routes recording Common Loon 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 →
Kittery PtMAINE72024
StraffordNEW-HAMPSHIRE32024
MarionMASSACHUSETTS22024
LittletonMASSACHUSETTS11991
HoldenMASSACHUSETTS12012
BrentwoodNEW-HAMPSHIRE11981
DoverNEW-HAMPSHIRE12013
EpsomNEW-HAMPSHIRE12019

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