BirdAnalyst
Species · BCR 2 · BBS 2025 Release · 1966–2024

Common Merganser In BCR 2

All regionsBCR 2Waterfowl

Common Merganser in BCR 2 has collapsed: down 79% on the route-weighted index since 1994.

-79%Since 1994
10Routes In Region
20Years

Notable Signals

long arc declinecomputed index

Common Merganser has collapsed in BCR 2: down 79% on the route-weighted index since 1994.

Forecast

If the recent trend holds, Common Merganser in BCR 2 is projected to fall about 100% by 2029 — from 0.78 in 2024 to a central estimate of 0.00 (95% range 0.00–2.1). A 5-year backtest shows a typical error of ±227.9%, with 100% of held-out values landing inside the 95% band.

-100%Change by 2029
0.00Projected 2029 index
0.00–2.195% range
±227.9%Backtest error
19842029
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
20250.000.002.1
20260.000.002.1
20270.000.002.1
20280.000.002.1
20290.000.002.1

Routes In BCR 2

Routes recording Common Merganser in BCR 2.
Katmai N.P.ALASKA222005
Cold Bay (Short)ALASKA181984
Kodiak 2ALASKA62024
Salmon LakeALASKA52019
Goodnews BayALASKA42004
Togiak RiverALASKA32005
CouncilALASKA22019
Kanektok RivALASKA22003
ChiniakALASKA12024
Cape NomeALASKA12017

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