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Species · Washington · BBS 2025 Release · 1966–2024

Pelagic Cormorant Population Trend in Washington

All statesWetland birds

Pelagic Cormorant in Washington has fallen sharply: down 53% on the route-weighted index since 1971.

-53%Since 1971TrendPercent 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 →
33YearsYears 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 WashingtonNotable 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 fallen sharply in Washington: down 53% on the route-weighted index since 1971.

Pelagic Cormorant Population Forecast in Washington

If the recent trend holds, Pelagic Cormorant in Washington is projected to stay roughly flat through 2027, near 1.0 (95% range 0.00–3.2). A 5-year backtest shows a typical error of ±5263.3%, 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 →
1.0Projected 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 →
0.00–3.295% 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 →
±5263.3%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 Washington is projected to stay roughly flat through 2027, near 1.0 (95% range 0.00–3.2). A 5-year backtest shows a typical error of ±5263.3%, with 100% of held-out values landing inside the 95% band.19692027
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 →
20231.00.003.2
20241.00.003.2
20251.00.003.2
20261.00.003.2
20271.00.003.2

Pelagic Cormorant Survey Routes in Washington

Routes recording Pelagic Cormorant in Washington.
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 →
Ozette319871974
Taholah220221969
Ilwaco120181992
Port Angeles120091981

Pelagic Cormorant Population Trend in Other States

alaskacaliforniaoregon

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