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Species · Rhode Island · BBS 2026 Release · 1966–2025

Great Black-backed Gull Population Trend in Rhode Island

All statesWetland birds

Great Black-backed Gull in Rhode Island has surged: up 179% on the route-weighted index since 1971.

+179%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 →
34YearsYears 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 179% 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 269% by 2030 — from 22 in 2025 to a central estimate of 82 (95% range 17–147). A 5-year backtest shows a typical error of ±4168.7%, with 60% of held-out values landing inside the 95% band.

+269%Change by 2030TrendPercent 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 →
82Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
17–14795% 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 →
±4168.7%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 269% by 2030 — from 22 in 2025 to a central estimate of 82 (95% range 17–147). A 5-year backtest shows a typical error of ±4168.7%, with 60% of held-out values landing inside the 95% band.19672030
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 →
20267611142
20277813143
20287914145
20298116146
20308217147

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 Island8920251990
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 2026-08-14.