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

Ring-billed Gull Population Trend in Wisconsin

All statesWetland birds

Ring-billed Gull in Wisconsin has declined: down 32% on the route-weighted index since 1969.

-32%Since 1969TrendPercent 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 →
49Routes 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 →
56YearsYears 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 WisconsinNotable 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 Ring-billed Gull in Wisconsin. See the full index history below.

Ring-billed Gull Population Forecast in Wisconsin

If the recent trend holds, Ring-billed Gull in Wisconsin is projected to rise about 751% by 2029 — from 0.84 in 2024 to a central estimate of 7.1 (95% range 0.00–18). A 5-year backtest shows a typical error of ±650.3%, with 100% of held-out values landing inside the 95% band.

+751%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 →
7.1Projected 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 →
0.00–1895% 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 →
±650.3%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 Wisconsin is projected to rise about 751% by 2029 — from 0.84 in 2024 to a central estimate of 7.1 (95% range 0.00–18). A 5-year backtest shows a typical error of ±650.3%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20256.90.0017
20267.00.0017
20277.00.0017
20287.10.0018
20297.10.0018

Ring-billed Gull Survey Routes in Wisconsin

Routes recording Ring-billed Gull in Wisconsin.
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 →
Omro9620011979
Holland4620241998
Wis Rapids3420231989
Kiel3420221998
Cumberland2020051989
Brownsville1820102010
Couderay1620121993
Crandon1320152005
Verona1220232004
Dresser819931987
Omro 2820242002
Chaffey720161975
Rib Lake620122012
Rolling Pr620241997
Iron River420241986
Shanagolden319961996
Washington I320241967
Esdaile320032003
Stratford320132013
Manitowoc320231981
Amnicon Falls320231998
Conover320192019
Buena Vista320142014
Minong220031987
Grand View220002000

Ring-billed Gull Population Trend in Other States

alabamaarizonacaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatexasutahvermontvirginiawashingtonwest-virginiawyoming

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