BirdAnalyst
Species · BCR 4 · BBS 2025 Release · 1966–2024

Red-breasted Merganser In BCR 4

All regionsBCR 4Waterfowl

Red-breasted Merganser in BCR 4 has surged: up 382% on the route-weighted index since 1991.

+382%Since 1991
16Routes In Region
34Years

Notable Signals

long arc increasecomputed index

Red-breasted Merganser has surged in BCR 4: up 382% on the route-weighted index since 1991.

Forecast

If the recent trend holds, Red-breasted Merganser in BCR 4 is projected to rise about 66% by 2029 — from 0.58 in 2024 to a central estimate of 0.97 (95% range 0.15–1.8). A 5-year backtest shows a typical error of ±49.7%, with 100% of held-out values landing inside the 95% band.

+66%Change by 2029
0.97Projected 2029 index
0.15–1.895% range
±49.7%Backtest error
19872029
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
20250.900.081.7
20260.920.101.7
20270.930.121.8
20280.950.131.8
20290.970.151.8

Routes In BCR 4

Routes recording Red-breasted Merganser in BCR 4.
Anvik RiverALASKA112024
Unalakleet RiverALASKA52024
Kanuti CanynALASKA42024
MaclarenALASKA31987
KalifonskyALASKA32013
SlanaALASKA22013
MonahanALASKA21991
Nicholai SlALASKA21999
Seven LakesALASKA22019
Manley Ht SpALASKA22015
Porcupine R.ALASKA22000
Kanuti LakeALASKA22015
Paxson LakeALASKA21996
Kenny LakeALASKA11988
Anchor RiverALASKA12024
TatalinaALASKA12012

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