BirdAnalyst
Species · BCR 14 · BBS 2026 Release · 1966–2025

Hooded Merganser In Atlantic Northern Forest

All regionsAtlantic Northern ForestWaterfowl

Hooded Merganser in Atlantic Northern Forest has surged: up 598% on the route-weighted index since 1969.

+598%Since 1969TrendPercent 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 →
67Routes 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 →
51YearsYears 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 Atlantic Northern Forest. See the full index history below.

Hooded Merganser In Atlantic Northern Forest Population Forecast

If the recent trend holds, Hooded Merganser in Atlantic Northern Forest is projected to fall about 33% by 2030 — from 0.18 in 2025 to a central estimate of 0.12 (95% range 0.04–0.20). A 5-year backtest shows a typical error of ±42.2%, with 40% of held-out values landing inside the 95% band.

-33%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 →
0.12Projected 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 →
0.04–0.2095% 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 →
±42.2%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 Atlantic Northern Forest is projected to fall about 33% by 2030 — from 0.18 in 2025 to a central estimate of 0.12 (95% range 0.04–0.20). A 5-year backtest shows a typical error of ±42.2%, with 40% 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 →
20260.110.030.20
20270.120.030.20
20280.120.030.20
20290.120.030.20
20300.120.040.20

Routes In Atlantic Northern Forest

Routes recording Hooded Merganser in Atlantic Northern Forest.
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 →
StacyvilleMAINE72021
W RutlandVERMONT72025
Bowdoin CtrMAINE61994
FranconiaNEW-HAMPSHIRE42014
HarmonyMAINE32024
Brownfield 2MAINE32021
Dixville Notch 2NEW-HAMPSHIRE32018
SpeculatorNEW-YORK31980
BrooksMAINE22013
CarrabassettMAINE22008
CharlestonMAINE21993
JeffersonMAINE22008
MontereyMASSACHUSETTS22019
Dixvil NotchNEW-HAMPSHIRE22013
Jeffers NtchNEW-HAMPSHIRE22016
Post MillsVERMONT22025
NewcastleMAINE12003
Wilson MillsMAINE12019
GreenwoodMAINE12017
ReedsMAINE12010
Otisfield GrMAINE12014
HartfordMAINE12009
ManchesterMAINE11982
EastbrookMAINE12019
HancockMAINE12010

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