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

Cassin's Vireo In Northern Pacific Rainforest

All regionsNorthern Pacific RainforestForest birds

Cassin's Vireo in Northern Pacific Rainforest has edged down: down 19% on the route-weighted index since 1970.

-19%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 →
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 →

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 98% by 2029 — from 1.0 in 2024 to a central estimate of 2.0 (95% range 0.33–3.7). A 5-year backtest shows a typical error of ±142.9%, with 40% of held-out values landing inside the 95% band.

+98%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 →
2.0Projected 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 →
0.33–3.795% 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 →
±142.9%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 98% by 2029 — from 1.0 in 2024 to a central estimate of 2.0 (95% range 0.33–3.7). A 5-year backtest shows a typical error of ±142.9%, with 40% 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 →
20252.10.423.8
20262.10.403.8
20272.10.383.8
20282.10.353.7
20292.00.333.7

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
Martins FyCALIFORNIA172009
LongvaleCALIFORNIA142023
RuchOREGON142023
Shasta LakeCALIFORNIA122024
Friday RidgeCALIFORNIA122024
HullvilleCALIFORNIA112019
Secret ValOREGON112022
ProspectOREGON112024
OrleansCALIFORNIA102012
Hay ForkCALIFORNIA102017
CecilvilleCALIFORNIA82017
SelmaOREGON82024
HolmesCALIFORNIA72024
WhiskeytownCALIFORNIA62007
Pilot CreekCALIFORNIA61996
CamasWASHINGTON62009
Offield MtnCALIFORNIA52014
Mt ShastaCALIFORNIA52019
KorbelCALIFORNIA52024
UkiahCALIFORNIA52011
Burnt RanchCALIFORNIA52016
HoneydewCALIFORNIA42017

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