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Species · Rhode Island · BBS 2025 Release · 1966–2024

Great Black-backed Gull Population Trend in Rhode Island

All statesWetland birds

Great Black-backed Gull in Rhode Island has surged: up 324% on the route-weighted index since 1971.

+324%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 →
3Routes 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 →
33YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Great Black-backed Gull Trends in Rhode IslandNotable 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 →

Great Black-backed Gull has surged in Rhode Island: up 324% on the route-weighted index since 1971.

Great Black-backed Gull Population Forecast in Rhode Island

If the recent trend holds, Great Black-backed Gull in Rhode Island is projected to rise about 181× by 2028 — from 0.50 in 2023 to a central estimate of 91 (95% range 27–154). A 5-year backtest shows a typical error of ±3730.6%, with 60% of held-out values landing inside the 95% band.

181×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 →
91Projected 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 →
27–15495% 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 →
±3730.6%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, Great Black-backed Gull in Rhode Island is projected to rise about 181× by 2028 — from 0.50 in 2023 to a central estimate of 91 (95% range 27–154). A 5-year backtest shows a typical error of ±3730.6%, with 60% of held-out values landing inside the 95% band.19672028
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 →
20248421147
20258522149
20268724150
20278926152
20289127154

Great Black-backed Gull Survey Routes in Rhode Island

Routes recording Great Black-backed Gull in Rhode Island.
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 →
Block Island8320101990
Sachuest Pt2319891967
Shannock120232023

Great Black-backed Gull Population Trend in Other States

connecticutdelawaremainemarylandmassachusettsnew-hampshirenew-jerseynew-yorknorth-carolinaohiovermontvirginia

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