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Species · Alaska · BBS 2025 Release · 1966–2024

Herring Gull Population Trend in Alaska

All statesWetland birds

Herring Gull in Alaska has collapsed: down 96% on the route-weighted index since 1972.

-96%Since 1972TrendPercent 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 →
59Routes 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 →
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 Herring Gull Trends in AlaskaNotable 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 Alaska: down 96% on the route-weighted index since 1972.

Herring Gull Population Forecast in Alaska

If the recent trend holds, Herring Gull in Alaska is projected to fall about 100% by 2029 — from 0.52 in 2024 to a central estimate of 0.00 (95% range 0.00–72). A 5-year backtest shows a typical error of ±2028.5%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–7295% 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 →
±2028.5%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 Alaska is projected to fall about 100% by 2029 — from 0.52 in 2024 to a central estimate of 0.00 (95% range 0.00–72). A 5-year backtest shows a typical error of ±2028.5%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20250.000.0072
20260.000.0072
20270.000.0072
20280.000.0072
20290.000.0072

Herring Gull Survey Routes in Alaska

Routes recording Herring Gull in Alaska.
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 →
Kalifonsky32220231982
Cohoe2120232012
Zimovia Strt2020021997
Chistochina1320241990
Yakutat920221999
Nicholai Sl620181997
Tonsina620162014
Porcupine R.520021993
Kenny Lake520242002
Kuskulana420241990
Juneau419911991
Delta420241998
Seven Lakes420231988
Northway320222022
Goose Bay319821975
Unalakleet River319991999
Skagway320191995
Kachemak320241996
Lake Louise320121995
Hope320152002
Maclaren220241982
Monahan220211983
Stikine River220022002
Cape Nome220121993
Mcgrath220191997

Herring Gull Population Trend in Other States

alabamacaliforniacoloradoconnecticutdelawarefloridaidahoillinoisindianakansaslouisianamainemarylandmassachusettsmichiganminnesotamontananew-hampshirenew-jerseynew-yorknorth-carolinaohiooregonpennsylvaniarhode-islandsouth-carolinatexasvermontvirginiawashingtonwest-virginiawisconsin

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