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

Glaucous-winged Gull In BCR 2

All regionsBCR 2Wetland birds

Glaucous-winged Gull in BCR 2 has fallen sharply: down 75% on the route-weighted index since 1985.

-75%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 →
41YearsYears 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 75% 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 2029 — from 8.6 in 2024 to a central estimate of 0.00 (95% range 0.00–31). A 5-year backtest shows a typical error of ±194%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–3195% 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 →
±194%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 2029 — from 8.6 in 2024 to a central estimate of 0.00 (95% range 0.00–31). A 5-year backtest shows a typical error of ±194%, with 100% of held-out values landing inside the 95% band.19832029
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 →
20250.000.0031
20260.000.0031
20270.000.0031
20280.000.0031
20290.000.0031

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 →
Cape NomeALASKA632024
Kodiak 2ALASKA462023
Cold Bay (Short)ALASKA281992
DillinghamALASKA202017
KodiakALASKA111984
Togiak RiverALASKA112005
King SalmonALASKA82024
Goodnews BayALASKA82005
Dillingham (Short)ALASKA71984
Salmon LakeALASKA52024
CouncilALASKA42023
Kanektok RivALASKA22005
Katmai N.P.ALASKA12022
ChiniakALASKA12023
Cold BayALASKA12024
Gweek RiverALASKA12000
TupuknukALASKA11995

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