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Species · Virginia · BBS 2025 Release · 1966–2024

Great Black-backed Gull Population Trend in Virginia

All statesWetland birds

Great Black-backed Gull in Virginia has edged down: down 11% on the route-weighted index since 1996.

-11%Since 1996TrendPercent 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 →
4Routes 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 →
20YearsYears 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 VirginiaNotable 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 Virginia. See the full index history below.

Great Black-backed Gull Population Forecast in Virginia

If the recent trend holds, Great Black-backed Gull in Virginia is projected to stay roughly flat through 2027, near 0.14 (95% range 0.00–0.38). A 5-year backtest shows a typical error of ±556.7%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2027TrendPercent 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 →
0.14Projected 2027 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.3895% 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 →
±556.7%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 Virginia is projected to stay roughly flat through 2027, near 0.14 (95% range 0.00–0.38). A 5-year backtest shows a typical error of ±556.7%, with 100% of held-out values landing inside the 95% band.19842027
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 →
20230.140.000.38
20240.140.000.38
20250.140.000.38
20260.140.000.38
20270.140.000.38

Great Black-backed Gull Survey Routes in Virginia

Routes recording Great Black-backed Gull in Virginia.
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 →
Quinby119841984
Colonial Pky119981996
Chincoteag W120222012
Cape Charles120181995

Great Black-backed Gull Population Trend in Other States

connecticutdelawaremainemarylandmassachusettsnew-hampshirenew-jerseynew-yorknorth-carolinaohiorhode-islandvermont

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