BirdAnalyst
Species · BCR 15 · BBS 2025 Release · 1966–2024

Cassin's Vireo In Sierra Nevada

All regionsSierra NevadaForest birds

Cassin's Vireo in Sierra Nevada has edged up: up 21% on the route-weighted index since 1972.

+21%Since 1972
37Routes In Region
54Years

Notable Signals

No notable trend signals for Cassin's Vireo in Sierra Nevada. See the full index history below.

Forecast

If the recent trend holds, Cassin's Vireo in Sierra Nevada is projected to rise about 48% by 2029 — from 5.5 in 2024 to a central estimate of 8.2 (95% range 5.5–11). A 5-year backtest shows a typical error of ±25.2%, with 80% of held-out values landing inside the 95% band.

+48%Change by 2029
8.2Projected 2029 index
5.5–1195% range
±25.2%Backtest error
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 index95% low95% high
20257.95.111
20267.95.211
20278.05.311
20288.15.411
20298.25.511

Routes In Sierra Nevada

Routes recording Cassin's Vireo in Sierra Nevada.
Forest HillCALIFORNIA272022
Butte MeadowCALIFORNIA262014
LumberyardCALIFORNIA182024
Forest Hill 2CALIFORNIA182005
RivertonCALIFORNIA172023
DownievilleCALIFORNIA142024
GeneseeCALIFORNIA132024
PlacervilleCALIFORNIA122024
ChesterCALIFORNIA112017
Eagle LakeCALIFORNIA92024
WestvilleCALIFORNIA92024
StrawberryCALIFORNIA92019
JohnsvilleCALIFORNIA52024
Tuolumne GroveCALIFORNIA52024
Hat CreekCALIFORNIA52018
Last ChanceCALIFORNIA52019
Chaos CraterCALIFORNIA42019
PaxtonCALIFORNIA42024
WawonaCALIFORNIA42024
ChilcootCALIFORNIA42024
Cottage SpgsCALIFORNIA31975
Bass LakeCALIFORNIA32018
GoumazCALIFORNIA32011
DardanelleCALIFORNIA22018
WoodfordsCALIFORNIA22024

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