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Species · Alaska · BBS 2025 Release · 1966–2024

Pelagic Cormorant Population Trend in Alaska

All statesWetland birds

Pelagic Cormorant in Alaska has collapsed: down 77% on the route-weighted index since 1985.

-77%Since 1985TrendPercent 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 →
9Routes 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 →
31YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Pelagic Cormorant 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 →

Pelagic Cormorant has collapsed in Alaska: down 77% on the route-weighted index since 1985.

Pelagic Cormorant Population Forecast in Alaska

If the recent trend holds, Pelagic Cormorant in Alaska is projected to fall about 100% by 2029 — from 0.07 in 2024 to a central estimate of 0.00 (95% range 0.00–0.28). A 5-year backtest shows a typical error of ±181.5%, 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 →
0.00–0.2895% 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 →
±181.5%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, Pelagic Cormorant in Alaska is projected to fall about 100% by 2029 — from 0.07 in 2024 to a central estimate of 0.00 (95% range 0.00–0.28). A 5-year backtest shows a typical error of ±181.5%, with 100% of held-out values landing inside the 95% band.19832029
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 →
20250.000.000.28
20260.000.000.28
20270.000.000.28
20280.000.000.28
20290.000.000.28

Pelagic Cormorant Survey Routes in Alaska

Routes recording Pelagic Cormorant 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 →
Sitka320242010
Cape Nome220121993
Yakutat220242008
Chiniak120151987
Kodiak 2120091988
Nome119971997
Adak120011983
Cold Bay (Short)119911991
Kodiak119831983

Pelagic Cormorant Population Trend in Other States

californiaoregonwashington

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