BirdAnalyst
Species · Washington · BBS 2025 Release · 1966–2024

Ring-billed Gull Population Trend in Washington

All statesWetland birds

Ring-billed Gull in Washington has collapsed: down 76% on the route-weighted index since 1972.

-76%Since 1972TrendPercent 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 →
48Routes 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 →
54YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Ring-billed Gull Trends in WashingtonNotable 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 →

Ring-billed Gull has collapsed in Washington: down 76% on the route-weighted index since 1972.

Ring-billed Gull Population Forecast in Washington

If the recent trend holds, Ring-billed Gull in Washington is projected to fall about 32% by 2029 — from 1.7 in 2024 to a central estimate of 1.1 (95% range 0.00–11). A 5-year backtest shows a typical error of ±161.2%, with 100% of held-out values landing inside the 95% band.

-32%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 →
1.1Projected 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 →
0.00–1195% 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 →
±161.2%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, Ring-billed Gull in Washington is projected to fall about 32% by 2029 — from 1.7 in 2024 to a central estimate of 1.1 (95% range 0.00–11). A 5-year backtest shows a typical error of ±161.2%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20251.80.0012
20261.60.0012
20271.50.0012
20281.30.0011
20291.10.0011

Ring-billed Gull Survey Routes in Washington

Routes recording Ring-billed Gull in Washington.
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 →
Hanford Site21119961988
Othello14819911981
Mesa8220081994
Keystone8020241994
Cougar5819921971
Potholes2220232006
Brewster1920111977
Moses Lake1720221973
Tonasket1220081984
Warm Beach 21120242024
Ardenvoir719861971
Ewan620121983
Warm Beach520041971
Harrington420121977
Reardan420061981
Malden420122001
Deception319971993
Columbia Nwr320211992
Prescott320032003
Horn Rapids320242005
Twisp219901980
Wapato219931972
Wilbur219941987
Nighthawk220071999
Hartline220041994

Ring-billed Gull Population Trend in Other States

alabamaarizonacaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatexasutahvermontvirginiawest-virginiawisconsinwyoming

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