BirdAnalyst
Species · BCR 5 · BBS 2026 Release · 1966–2025

Cassin's Vireo In Northern Pacific Rainforest

All regionsNorthern Pacific RainforestForest birds

Cassin's Vireo in Northern Pacific Rainforest has edged down: down 11% on the route-weighted index since 1970.

-11%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 →
114Routes 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 →
57YearsYears 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 →

No notable trend signals for Cassin's Vireo in Northern Pacific Rainforest. See the full index history below.

Cassin's Vireo In Northern Pacific Rainforest Population Forecast

If the recent trend holds, Cassin's Vireo in Northern Pacific Rainforest is projected to rise about 51% by 2030 — from 1.3 in 2025 to a central estimate of 1.9 (95% range 0.24–3.6). A 5-year backtest shows a typical error of ±154.4%, with 60% of held-out values landing inside the 95% band.

+51%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 →
1.9Projected 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 →
0.24–3.695% 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 →
±154.4%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, Cassin's Vireo in Northern Pacific Rainforest is projected to rise about 51% by 2030 — from 1.3 in 2025 to a central estimate of 1.9 (95% range 0.24–3.6). A 5-year backtest shows a typical error of ±154.4%, with 60% of held-out values landing inside the 95% band.19682030
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 →
20262.00.343.7
20272.00.323.7
20282.00.293.7
20292.00.273.7
20301.90.243.6

Routes In Northern Pacific Rainforest

Routes recording Cassin's Vireo 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 →
Horse CreekCALIFORNIA442019
Orleans 2CALIFORNIA232014
AlderpointCALIFORNIA212012
Shasta LakeCALIFORNIA202025
Martins FyCALIFORNIA172009
Secret ValOREGON152025
LongvaleCALIFORNIA142023
RuchOREGON142023
HullvilleCALIFORNIA112019
OrleansCALIFORNIA102012
Hay ForkCALIFORNIA102017
CecilvilleCALIFORNIA82017
LaytonvilleCALIFORNIA72025
ProspectOREGON72025
WhiskeytownCALIFORNIA62007
Pilot CreekCALIFORNIA61996
CamasWASHINGTON62009
Offield MtnCALIFORNIA52014
Mt ShastaCALIFORNIA52019
UkiahCALIFORNIA52011
Burnt RanchCALIFORNIA52016
Sams ValleyOREGON52025
Emigrant Lake 2OREGON52025
HoneydewCALIFORNIA42017
HolmesCALIFORNIA42025

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