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Species · Oregon · BBS 2025 Release · 1966–2024

California Gull Population Trend in Oregon

All statesWetland birds

California Gull in Oregon has surged: up 201% on the route-weighted index since 1971.

+201%Since 1971TrendPercent 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 StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
53YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable California 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 →

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 →

California Gull has surged in Oregon: up 201% on the route-weighted index since 1971.

California Gull Population Forecast in Oregon

If the recent trend holds, California Gull in Oregon is projected to rise about 105% by 2028 — from 0.35 in 2023 to a central estimate of 0.72 (95% range 0.00–4.0). A 5-year backtest shows a typical error of ±1051.6%, with 100% of held-out values landing inside the 95% band.

+105%Change by 2028TrendPercent 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 →
0.72Projected 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–4.095% 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 →
±1051.6%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, California Gull in Oregon is projected to rise about 105% by 2028 — from 0.35 in 2023 to a central estimate of 0.72 (95% range 0.00–4.0). A 5-year backtest shows a typical error of ±1051.6%, with 100% of held-out values landing inside the 95% band.19692028
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 →
20240.750.004.0
20250.740.004.0
20260.740.004.0
20270.730.004.0
20280.720.004.0

California Gull Survey Routes in Oregon

Routes recording California 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 →
Merrill25020222003
Umatilla2920231996
Princeton2519851972
Crane1419981995
Ordnance1319791972
Bridgeport519881988
Barnes Val419741973
Harney Lake420061993
Wedderburn319961970
Sparta320011971
Clover Creek319971997
Alvord Lake220001988
Joseph219911991
Flook Lake220111998
Tualatin119771971
Lapham Res.119941994
Dell Spring119701970
Fandango Can119981984
Malheur Nwr119911986
Modoc Point120141969
Adair119971989
Mt Hood119951995
Pendleton119841984
Hazel Camp120091996
Fish Lake120211977

California Gull Population Trend in Other States

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