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

Herring Gull In Southeastern Coastal Plain

All regionsSoutheastern Coastal PlainWetland birds

Herring Gull in Southeastern Coastal Plain has collapsed: down 93% on the route-weighted index since 1968.

-93%Since 1968TrendPercent 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 →
19Routes 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 →
49YearsYears 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 →

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 →

Herring Gull has collapsed in Southeastern Coastal Plain: down 93% on the route-weighted index since 1968.

Herring Gull In Southeastern Coastal Plain Population Forecast

If the recent trend holds, Herring Gull in Southeastern Coastal Plain is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.22). A 5-year backtest shows a typical error of ±254.5%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.00Projected 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 →
0.00–0.2295% 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 →
±254.5%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, Herring Gull in Southeastern Coastal Plain is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.22). A 5-year backtest shows a typical error of ±254.5%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20250.000.000.22
20260.000.000.22
20270.000.000.22
20280.000.000.22
20290.000.000.22

Routes In Southeastern Coastal Plain

Routes recording Herring 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 →
BackbayVIRGINIA501971
MashoesNORTH-CAROLINA411982
NewportNORTH-CAROLINA92015
Dauphin Is 2ALABAMA22000
MerrimonNORTH-CAROLINA22023
GrandyNORTH-CAROLINA21974
Johns IsleSOUTH-CAROLINA21977
Dauphin IsALABAMA11990
Alabama PtALABAMA11996
Alabama Pt 2ALABAMA12012
Ft Waltn BchFLORIDA12009
Port St JoeFLORIDA11990
Ft GadsdenFLORIDA11988
Santa RosaFLORIDA11989
Myrtle GroveNORTH-CAROLINA12015
SupplyNORTH-CAROLINA11994
Milltail CrNORTH-CAROLINA12024
JarvisburgNORTH-CAROLINA11999
PungoVIRGINIA11993

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