BirdAnalyst
Species · BCR 27 · BBS 2025 Release · 1966–2024

Great Black-backed Gull In Southeastern Coastal Plain

All regionsSoutheastern Coastal PlainWetland birds

Great Black-backed Gull in Southeastern Coastal Plain has fallen sharply: down 75% on the route-weighted index since 1982.

-75%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 RegionSurvey 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 SignalsNotable 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 Great Black-backed Gull in Southeastern Coastal Plain. See the full index history below.

Great Black-backed Gull In Southeastern Coastal Plain Population Forecast

If the recent trend holds, Great Black-backed Gull in Southeastern Coastal Plain is projected to stay roughly flat through 2026, near 0.00 (95% range 0.00–0.02). A 5-year backtest shows a typical error of ±107.9%, 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 →
0.00–0.0295% 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 →
±107.9%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 Southeastern Coastal Plain is projected to stay roughly flat through 2026, near 0.00 (95% range 0.00–0.02). A 5-year backtest shows a typical error of ±107.9%, 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 →
20220.010.000.02
20230.000.000.02
20240.000.000.02
20250.000.000.02
20260.000.000.02

Routes In Southeastern Coastal Plain

Routes recording Great Black-backed Gull in Southeastern Coastal Plain.
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 →
MashoesNORTH-CAROLINA41982
MerrimonNORTH-CAROLINA12013
GrandyNORTH-CAROLINA11974
Milltail CrNORTH-CAROLINA12021
NewportNORTH-CAROLINA12002

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