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

Greater Scaup In BCR 2

All regionsBCR 2Waterfowl

Greater Scaup in BCR 2 has surged: up 173% on the route-weighted index since 1986.

+173%Since 1986TrendPercent 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 →
19Routes 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 increasecomputed 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 surged in BCR 2: up 173% on the route-weighted index since 1986.

Forecast

If the recent trend holds, Greater Scaup in BCR 2 is projected to fall about 53% by 2029 — from 42 in 2024 to a central estimate of 20 (95% range 4.6–34). A 5-year backtest shows a typical error of ±42.1%, with 80% of held-out values landing inside the 95% band.

-53%Change by 2029TrendPercent 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 →
20Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
4.6–3495% 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 →
±42.1%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, Greater Scaup in BCR 2 is projected to fall about 53% by 2029 — from 42 in 2024 to a central estimate of 20 (95% range 4.6–34). A 5-year backtest shows a typical error of ±42.1%, with 80% of held-out values landing inside the 95% band.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 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 →
2025183.433
2026193.733
2027194.034
2028194.334
2029204.634

Routes In BCR 2

Routes recording Greater Scaup in BCR 2.
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 →
KotzebueALASKA2962024
Kotzebue (Short)ALASKA1071994
Cape NomeALASKA432024
Cold BayALASKA322024
Cold Bay (Short)ALASKA111992
Kodiak 2ALASKA91997
DillinghamALASKA62013
CouncilALASKA52024
NomeALASKA42021
ChiniakALASKA22021
King SalmonALASKA22019
TellerALASKA22011
Gweek RiverALASKA22001
TupuknukALASKA21995
Kugarak (Short)ALASKA21987
Katmai N.P.ALASKA12000
Salmon LakeALASKA12019
St. Mary'SALASKA11998
Goodnews BayALASKA12003

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