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Species · BCR 4 · BBS 2026 Release · 1966–2025

White-winged Scoter In BCR 4

All regionsBCR 4Waterfowl

White-winged Scoter in BCR 4 has declined: down 43% on the route-weighted index since 1989.

-43%Since 1989TrendPercent 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 →
12Routes 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 →
27YearsYears 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 White-winged Scoter in BCR 4. See the full index history below.

White-winged Scoter In BCR 4 Population Forecast

If the recent trend holds, White-winged Scoter in BCR 4 is projected to fall about 68% by 2030 — from 0.32 in 2025 to a central estimate of 0.10 (95% range 0.00–0.56). A 5-year backtest shows a typical error of ±197.1%, with 40% of held-out values landing inside the 95% band.

-68%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 →
0.10Projected 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 →
0.00–0.5695% 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 →
±197.1%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, White-winged Scoter in BCR 4 is projected to fall about 68% by 2030 — from 0.32 in 2025 to a central estimate of 0.10 (95% range 0.00–0.56). A 5-year backtest shows a typical error of ±197.1%, with 40% of held-out values landing inside the 95% band.19832030
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 →
20260.120.000.58
20270.120.000.57
20280.110.000.57
20290.110.000.57
20300.100.000.56

Routes In BCR 4

Routes recording White-winged Scoter in BCR 4.
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 →
TonsinaALASKA222018
Mccarthy Rd2ALASKA82025
Hather CreekALASKA61994
SourdoughALASKA42025
CantwellALASKA32010
MonahanALASKA22003
Lake LouiseALASKA21993
NorthwayALASKA11994
Kenny LakeALASKA11989
ColdfootALASKA12002
Mud RiverALASKA11993
Kanuti LakeALASKA12012

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