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Species · BCR 2 · BBS 2026 Release · 1966–2025

Glaucous-winged Gull In BCR 2

All regionsBCR 2Wetland birds

Glaucous-winged Gull in BCR 2 has fallen sharply: down 66% on the route-weighted index since 1985.

-66%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 →
17Routes 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 →
42YearsYears 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 →

Glaucous-winged Gull has fallen sharply in BCR 2: down 66% on the route-weighted index since 1985.

Glaucous-winged Gull In BCR 2 Population Forecast

If the recent trend holds, Glaucous-winged Gull in BCR 2 is projected to fall about 100% by 2030 — from 17 in 2025 to a central estimate of 0.00 (95% range 0.00–32). A 5-year backtest shows a typical error of ±182.7%, 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 →
0.00–3295% 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 →
±182.7%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, Glaucous-winged Gull in BCR 2 is projected to fall about 100% by 2030 — from 17 in 2025 to a central estimate of 0.00 (95% range 0.00–32). A 5-year backtest shows a typical error of ±182.7%, 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 →
20260.000.0032
20270.000.0032
20280.000.0032
20290.000.0032
20300.000.0032

Routes In BCR 2

Routes recording Glaucous-winged Gull 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 →
Cold BayALASKA832025
Cape NomeALASKA632024
Cold Bay (Short)ALASKA281992
DillinghamALASKA202017
King SalmonALASKA122025
KodiakALASKA111984
Togiak RiverALASKA112005
Goodnews BayALASKA82005
Dillingham (Short)ALASKA71984
Kodiak 2ALASKA62025
Salmon LakeALASKA52024
CouncilALASKA42023
Kanektok RivALASKA22005
Katmai N.P.ALASKA12025
ChiniakALASKA12025
Gweek RiverALASKA12000
TupuknukALASKA11995

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