BirdAnalyst
Species · New Jersey · BBS 2025 Release · 1966–2024

Ring-billed Gull Population Trend in New Jersey

All statesWetland birds

Ring-billed Gull in New Jersey has surged: up 78% on the route-weighted index since 1977.

+78%Since 1977TrendPercent 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 →
14Routes 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 →
30YearsYears 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 New JerseyNotable 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 →

Ring-billed Gull has surged in New Jersey: up 78% on the route-weighted index since 1977.

Ring-billed Gull Population Forecast in New Jersey

If the recent trend holds, Ring-billed Gull in New Jersey is projected to fall about 37% by 2029 — from 0.95 in 2024 to a central estimate of 0.60 (95% range 0.00–2.2). A 5-year backtest shows a typical error of ±289.8%, with 100% of held-out values landing inside the 95% band.

-37%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 →
0.60Projected 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 →
0.00–2.295% 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 →
±289.8%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 New Jersey is projected to fall about 37% by 2029 — from 0.95 in 2024 to a central estimate of 0.60 (95% range 0.00–2.2). A 5-year backtest shows a typical error of ±289.8%, 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 →
20250.580.002.2
20260.590.002.2
20270.590.002.2
20280.590.002.2
20290.600.002.2

Ring-billed Gull Survey Routes in New Jersey

Routes recording Ring-billed Gull in New Jersey.
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 →
Six Points2020241983
Albion1220222007
Spraguetown219901990
Greenwich220012001
Toms River220051995
Clarksville219821982
Spraguetown 2120032003
Pedricktown120082008
Robbinsville119671967
Midvale119971996
Bloomsbury120111976
High Point120031994
Roosevelt120132001
Friendship120221977

Ring-billed Gull Population Trend in Other States

alabamaarizonacaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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