BirdAnalyst
Species · BCR 5 · BBS 2025 Release · 1966–2024

Brandt's Cormorant In Northern Pacific Rainforest

All regionsNorthern Pacific RainforestWetland birds

Brandt's Cormorant in Northern Pacific Rainforest has collapsed: down 76% on the route-weighted index since 1970.

-76%Since 1970TrendPercent 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 →
8Routes In RegionSurvey 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 SignalsNotable 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 →

Brandt's Cormorant has collapsed in Northern Pacific Rainforest: down 76% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Brandt's Cormorant in Northern Pacific Rainforest is projected to fall about 97% by 2022 — from 0.29 in 2017 to a central estimate of 0.01 (95% range 0.00–2.8). A 5-year backtest shows a typical error of ±290.7%, with 100% of held-out values landing inside the 95% band.

-97%Change by 2022TrendPercent 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 →
0.01Projected 2022 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–2.895% 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 →
±290.7%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, Brandt's Cormorant in Northern Pacific Rainforest is projected to fall about 97% by 2022 — from 0.29 in 2017 to a central estimate of 0.01 (95% range 0.00–2.8). A 5-year backtest shows a typical error of ±290.7%, with 100% of held-out values landing inside the 95% band.19682022
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 →
20180.110.002.9
20190.080.002.8
20200.060.002.8
20210.030.002.8
20220.010.002.8

Routes In Northern Pacific Rainforest

Routes recording Brandt's Cormorant in Northern Pacific Rainforest.
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 →
IlwacoWASHINGTON802009
HauserOREGON281979
Bodega BayCALIFORNIA232017
Fish RockCALIFORNIA32013
NavarroCALIFORNIA21980
Crescent CtyCALIFORNIA11982
HoneydewCALIFORNIA12017
TaholahWASHINGTON11997

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