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Species · North Carolina · BBS 2025 Release · 1966–2024

Great Black-backed Gull Population Trend in North Carolina

All statesWetland birds

Great Black-backed Gull in North Carolina has collapsed: down 88% on the route-weighted index since 1982.

-88%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 →
5Routes 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 Great Black-backed Gull Trends in North CarolinaNotable 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 declinecomputed 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 collapsed in North Carolina: down 88% on the route-weighted index since 1982.

Great Black-backed Gull Population Forecast in North Carolina

If the recent trend holds, Great Black-backed Gull in North Carolina is projected to stay roughly flat through 2026, near 0.00 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±73.9%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2026TrendPercent 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 →
0.00Projected 2026 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.1095% 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 →
±73.9%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 North Carolina is projected to stay roughly flat through 2026, near 0.00 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±73.9%, with 100% of held-out values landing inside the 95% band.19732026
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 →
20220.000.000.10
20230.000.000.10
20240.000.000.10
20250.000.000.10
20260.000.000.10

Great Black-backed Gull Survey Routes in North Carolina

Routes recording Great Black-backed Gull in North Carolina.
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 →
Mashoes419821973
Merrimon120132000
Newport120022002
Milltail Cr120211992
Grandy119741973

Great Black-backed Gull Population Trend in Other States

connecticutdelawaremainemarylandmassachusettsnew-hampshirenew-jerseynew-yorkohiorhode-islandvermontvirginia

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