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Species · BCR 12 · BBS 2025 Release · 1966–2024

Hooded Merganser In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionWaterfowl

Hooded Merganser in Boreal Hardwood Transition has increased: up 35% on the route-weighted index since 1970.

+35%Since 1970TrendPercent 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 →
68Routes 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 →
48YearsYears 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 Boreal Hardwood Transition. See the full index history below.

Hooded Merganser In Boreal Hardwood Transition Population Forecast

If the recent trend holds, Hooded Merganser in Boreal Hardwood Transition is projected to rise about 76% by 2029 — from 0.07 in 2024 to a central estimate of 0.12 (95% range 0.02–0.22). A 5-year backtest shows a typical error of ±29.4%, with 100% of held-out values landing inside the 95% band.

+76%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 →
0.12Projected 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 →
0.02–0.2295% 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 →
±29.4%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 Boreal Hardwood Transition is projected to rise about 76% by 2029 — from 0.07 in 2024 to a central estimate of 0.12 (95% range 0.02–0.22). A 5-year backtest shows a typical error of ±29.4%, 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 →
20250.110.010.22
20260.120.010.22
20270.120.010.22
20280.120.010.22
20290.120.020.22

Routes In Boreal Hardwood Transition

Routes recording Hooded Merganser in Boreal Hardwood Transition.
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 →
Tamarac NwrMINNESOTA32023
Crystal FlsMICHIGAN22023
RacoMICHIGAN22001
Pine RiverMINNESOTA22018
NebishMINNESOTA22013
BayfieldWISCONSIN22015
Popple RiverWISCONSIN22017
FlambeauWISCONSIN22013
BootjackMICHIGAN11998
Ned LakeMICHIGAN12009
HermanMICHIGAN11993
Gibbs CityMICHIGAN12009
Maple GroveMICHIGAN12023
IshpemingMICHIGAN12014
Brocky LakeMICHIGAN12008
ShingletonMICHIGAN12002
CreightonMICHIGAN12012
Bear LakeMICHIGAN12021
GilchristMICHIGAN11993
Skegemog PtMICHIGAN12001
PickfordMICHIGAN12019
FredericMICHIGAN11994
Pleasant Valley 2MICHIGAN12024
Walloon Lake 2MICHIGAN12024
Seney NwrMICHIGAN12019

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