BirdAnalyst
Species · Oregon · BBS 2025 Release · 1966–2024

Common Merganser Population Trend in Oregon

All statesWaterfowl

Common Merganser in Oregon has declined: down 28% on the route-weighted index since 1971.

-28%Since 1971
64Routes In State
55Years

Notable Common Merganser Trends in Oregon

No notable trend signals for Common Merganser in Oregon. See the full index history below.

Common Merganser Population Forecast in Oregon

If the recent trend holds, Common Merganser in Oregon is projected to rise about 30% by 2029 — from 0.28 in 2024 to a central estimate of 0.36 (95% range 0.00–1.5). A 5-year backtest shows a typical error of ±355.9%, with 100% of held-out values landing inside the 95% band.

+30%Change by 2029
0.36Projected 2029 index
0.00–1.595% range
±355.9%Backtest error
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 index95% low95% high
20250.360.001.5
20260.360.001.5
20270.360.001.5
20280.360.001.5
20290.360.001.5

Common Merganser Survey Routes in Oregon

Routes recording Common Merganser in Oregon.
Cool Camp31320132001
Joseph1320241981
Salado1120241980
Bull Run720232008
Sisters620162016
Molalla420211995
Glasgow420182016
Prospect420091999
Dell Spring319821982
Wedderburn320041970
Emigrant Lake 2320192019
Riley Peak220102009
Imnaha220172007
Logdell220221972
Bridgeport220221986
Winberry220131968
Bly 2220112008
Camp Sherman219961975
Mount Vernon220001991
Adrian220081984
Fisher220002000
Newbridge220071998
Myrtle Grove220042004
Salem219981998
Timber120132013

Common Merganser Population Trend in Other States

alaskaarizonacaliforniacoloradoconnecticutidahomainemarylandmassachusettsmichiganminnesotamontananevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-dakotaohiopennsylvaniasouth-dakotautahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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