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

Hooded Merganser In New England / Mid-Atlantic Coast

All regionsNew England / Mid-Atlantic CoastWaterfowl

Hooded Merganser in New England / Mid-Atlantic Coast has fallen sharply: down 56% on the route-weighted index since 1983.

-56%Since 1983TrendPercent 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 →
18Routes 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 →
28YearsYears 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 Hooded Merganser in New England / Mid-Atlantic Coast. See the full index history below.

Hooded Merganser In New England / Mid-Atlantic Coast Population Forecast

If the recent trend holds, Hooded Merganser in New England / Mid-Atlantic Coast is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.05). A 5-year backtest shows a typical error of ±26.6%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.01Projected 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 →
0.00–0.0595% 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 →
±26.6%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, Hooded Merganser in New England / Mid-Atlantic Coast is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.05). A 5-year backtest shows a typical error of ±26.6%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20250.010.000.05
20260.010.000.05
20270.010.000.05
20280.010.000.05
20290.010.000.05

Routes In New England / Mid-Atlantic Coast

Routes recording Hooded Merganser 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 →
Wallum LakeRHODE-ISLAND42012
EpsomNEW-HAMPSHIRE21993
BuckinghamCONNECTICUT12011
No WoodburyCONNECTICUT12003
DanburyCONNECTICUT11969
WarrenCONNECTICUT12006
Mid HaddamCONNECTICUT12022
CheltenhamMARYLAND11999
Piney NeckMARYLAND12006
Forest GroveMARYLAND12013
LittletonMASSACHUSETTS12013
BelchertownMASSACHUSETTS12015
HoldenMASSACHUSETTS12007
Warren 2MASSACHUSETTS12024
Ware RiverMASSACHUSETTS12017
DoverNEW-HAMPSHIRE11992
StraffordNEW-HAMPSHIRE12002
East KingstonNEW-HAMPSHIRE12017

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