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Species · Oregon · BBS 2026 Release · 1966–2025

Pelagic Cormorant Population Trend in Oregon

All statesWetland birds

Pelagic Cormorant in Oregon has surged: up 181% on the route-weighted index since 1976.

+181%Since 1976TrendPercent 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 →
21YearsYears 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 OregonNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Pelagic Cormorant in Oregon. See the full index history below.

Pelagic Cormorant Population Forecast in Oregon

If the recent trend holds, Pelagic Cormorant in Oregon is projected to rise about 24% by 2030 — from 0.09 in 2025 to a central estimate of 0.11 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±104.4%, with 40% of held-out values landing inside the 95% band.

+24%Change by 2030TrendPercent 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 →
0.11Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.3495% 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 →
±104.4%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 Oregon is projected to rise about 24% by 2030 — from 0.09 in 2025 to a central estimate of 0.11 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±104.4%, with 40% of held-out values landing inside the 95% band.19732030
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 →
20260.100.000.34
20270.100.000.34
20280.110.000.34
20290.110.000.34
20300.110.000.34

Pelagic Cormorant Survey Routes in Oregon

Routes recording Pelagic Cormorant in Oregon.
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 →
Wedderburn720251973
Glasgow220252012
Hauser119761976
Hazel Camp120072007

Pelagic Cormorant Population Trend in Other States

alaskacaliforniawashington

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.