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

Greater Scaup In BCR 4

All regionsBCR 4Waterfowl

Greater Scaup in BCR 4 has collapsed: down 83% on the route-weighted index since 1985.

-83%Since 1985TrendPercent 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 →
27Routes 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 →
40YearsYears 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 →

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Greater Scaup has collapsed in BCR 4: down 83% on the route-weighted index since 1985.

Greater Scaup In BCR 4 Population Forecast

If the recent trend holds, Greater Scaup in BCR 4 is projected to fall about 100% by 2030 — from 0.81 in 2025 to a central estimate of 0.00 (95% range 0.00–3.7). A 5-year backtest shows a typical error of ±220.7%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–3.795% 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 →
±220.7%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, Greater Scaup in BCR 4 is projected to fall about 100% by 2030 — from 0.81 in 2025 to a central estimate of 0.00 (95% range 0.00–3.7). A 5-year backtest shows a typical error of ±220.7%, with 100% 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 →
20260.000.003.7
20270.000.003.7
20280.000.003.7
20290.000.003.7
20300.000.003.7

Routes In BCR 4

Routes recording Greater Scaup 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 →
Pinoche Tral (Short)ALASKA621984
Nabesna RoadALASKA352024
Mccarthy Rd2ALASKA242025
Paxson LakeALASKA81997
CircleALASKA61995
CantwellALASKA62013
ToklatALASKA62000
KuskulanaALASKA62025
Kenny LakeALASKA42013
SlanaALASKA32019
ChistochinaALASKA32021
Ft. RichrdsnALASKA32000
MaclarenALASKA22024
MonahanALASKA22014
Bear CreekALASKA21986
KachemakALASKA22018
ColdfootALASKA22024
Donelly DomeALASKA22007
Kanuti CanynALASKA21994
Kanuti LakeALASKA22018
Galena (Short)ALASKA21985
SourdoughALASKA12023
Swan Lake RdALASKA12022
Seven LakesALASKA12024
Burma RoadALASKA12010

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