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Species · Alaska · BBS 2025 Release · 1966–2024

Bonaparte's Gull Population Trend in Alaska

All statesWetland birds

Bonaparte's Gull in Alaska has collapsed: down 79% on the route-weighted index since 1984.

-79%Since 1984TrendPercent 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 →
53Routes 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 →
42YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Bonaparte's 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 →

Bonaparte's Gull has collapsed in Alaska: down 79% on the route-weighted index since 1984.

Bonaparte's Gull Population Forecast in Alaska

If the recent trend holds, Bonaparte's Gull in Alaska is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–5.5). A 5-year backtest shows a typical error of ±1753.1%, 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 →
0.00–5.595% 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 →
±1753.1%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, Bonaparte's Gull in Alaska is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–5.5). A 5-year backtest shows a typical error of ±1753.1%, with 100% of held-out values landing inside the 95% band.19822029
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 →
20250.000.005.5
20260.000.005.5
20270.000.005.5
20280.000.005.5
20290.000.005.5

Bonaparte's Gull Survey Routes in Alaska

Routes recording Bonaparte's 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 →
Juneau Alt33519851985
Ketchikan5520171989
Petersburg2419871987
Zarembo2020012001
Bear Creek819881988
Nabesna Road520162004
Petersville519971986
Kuskulana419921992
Anvik River420141998
Sourdough420011983
Zimovia Strt420171999
Slana320131994
Monahan320161983
Cottonwood319901990
Mitkof Isle320101990
Yakutat320181997
Chiniak220212019
Chistochina219931990
Kuiu Island220102010
Haines219971995
Skagway220111995
Pinoche Tral (Short)219841984
Togiak River220032003
Sheep Mtn220171984
Paxson Lake119931993

Bonaparte's Gull Population Trend in Other States

californiamainenorth-dakotaoregonwashington

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