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

Ring-billed Gull Population Trend in Connecticut

All statesWetland birds

Ring-billed Gull in Connecticut has edged down: down 19% on the route-weighted index since 1982.

-19%Since 1982TrendPercent 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 →
8Routes 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 →
18YearsYears 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 ConnecticutNotable 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 Connecticut. See the full index history below.

Ring-billed Gull Population Forecast in Connecticut

If the recent trend holds, Ring-billed Gull in Connecticut is projected to rise about 22% by 2021 — from 0.23 in 2016 to a central estimate of 0.28 (95% range 0.00–0.70). A 5-year backtest shows a typical error of ±125.4%, with 80% of held-out values landing inside the 95% band.

+22%Change by 2021TrendPercent 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 →
0.28Projected 2021 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.7095% 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 →
±125.4%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 Connecticut is projected to rise about 22% by 2021 — from 0.23 in 2016 to a central estimate of 0.28 (95% range 0.00–0.70). A 5-year backtest shows a typical error of ±125.4%, with 80% of held-out values landing inside the 95% band.19732021
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 →
20170.270.000.69
20180.270.000.70
20190.280.000.70
20200.280.000.70
20210.280.000.70

Ring-billed Gull Survey Routes in Connecticut

Routes recording Ring-billed Gull in Connecticut.
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 →
Westbrook720061982
No Woodbury519971997
Willimantic320162016
Mystic219941973
Greenwich120141988
Danbury119891988
Warren120081996
Mid Haddam119931993

Ring-billed Gull Population Trend in Other States

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