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Species · Oregon · BBS 2025 Release · 1966–2024

Glaucous-winged Gull Population Trend in Oregon

All statesWetland birds

Glaucous-winged Gull in Oregon has edged down: down 17% on the route-weighted index since 1973.

-17%Since 1973TrendPercent 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 →
5Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
26YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Glaucous-winged Gull Trends in OregonNotable 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 Glaucous-winged Gull in Oregon. See the full index history below.

Glaucous-winged Gull Population Forecast in Oregon

If the recent trend holds, Glaucous-winged Gull in Oregon is projected to fall about 66% by 2020 — from 0.11 in 2015 to a central estimate of 0.04 (95% range 0.00–0.12). A 5-year backtest shows a typical error of ±111.1%, with 40% of held-out values landing inside the 95% band.

-66%Change by 2020TrendPercent 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 →
0.04Projected 2020 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.1295% 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 →
±111.1%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, Glaucous-winged Gull in Oregon is projected to fall about 66% by 2020 — from 0.11 in 2015 to a central estimate of 0.04 (95% range 0.00–0.12). A 5-year backtest shows a typical error of ±111.1%, with 40% of held-out values landing inside the 95% band.19682020
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 →
20160.040.000.12
20170.040.000.12
20180.040.000.12
20190.040.000.12
20200.040.000.12

Glaucous-winged Gull Survey Routes in Oregon

Routes recording Glaucous-winged Gull in Oregon.
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 →
Glasgow720151987
Tualatin119971968
Nicolai Mtn.120011993
Wedderburn120001972
Hazel Camp120111975

Glaucous-winged Gull Population Trend in Other States

alaskacaliforniawashington

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