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

Brown-headed Cowbird In Northern Pacific Rainforest

All regionsNorthern Pacific RainforestGeneralists

Brown-headed Cowbird 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 →
112Routes 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 →
56YearsYears 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 →

Brown-headed Cowbird has collapsed in Northern Pacific Rainforest: down 76% on the route-weighted index since 1970.

Brown-headed Cowbird In Northern Pacific Rainforest Population Forecast

If the recent trend holds, Brown-headed Cowbird in Northern Pacific Rainforest is projected to fall about 67% by 2029 — from 3.6 in 2024 to a central estimate of 1.2 (95% range 0.00–4.5). A 5-year backtest shows a typical error of ±55.1%, with 100% of held-out values landing inside the 95% band.

-67%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 →
1.2Projected 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 →
0.00–4.595% 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 →
±55.1%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, Brown-headed Cowbird in Northern Pacific Rainforest is projected to fall about 67% by 2029 — from 3.6 in 2024 to a central estimate of 1.2 (95% range 0.00–4.5). A 5-year backtest shows a typical error of ±55.1%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20251.70.005.0
20261.60.004.9
20271.50.004.8
20281.30.004.6
20291.20.004.5

Routes In Northern Pacific Rainforest

Routes recording Brown-headed Cowbird 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 →
SalemOREGON322024
Horse CreekCALIFORNIA202019
Nicolai Mtn.OREGON202024
Port AngelesWASHINGTON202024
YrekaCALIFORNIA172019
GarfieldOREGON172023
EverettWASHINGTON152024
CoquilleOREGON142024
GreenOREGON142024
MukilteoWASHINGTON122024
South ElmaWASHINGTON112024
Bay ViewWASHINGTON112017
ElktonOREGON102024
Emigrant LkOREGON102001
IssaquahWASHINGTON101987
Mendota 3WASHINGTON102024
HoneydewCALIFORNIA92017
SvensenOREGON91992
ScappooseOREGON92023
MendotaWASHINGTON91988
Rio DellCALIFORNIA82011
AlderpointCALIFORNIA82012
AdairOREGON82024
DaytonOREGON82024
Sams ValleyOREGON82024

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