BirdAnalyst
Species · BCR 9 · BBS 2025 Release · 1966–2024

Cassin's Vireo In Great Basin

All regionsGreat BasinForest birds

Cassin's Vireo in Great Basin has surged: up 100% on the route-weighted index since 1970.

+100%Since 1970
77Routes In Region
56Years

Notable Signals

long arc increasecomputed index

Cassin's Vireo has surged in Great Basin: up 100% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Cassin's Vireo in Great Basin is projected to rise about 37% by 2029 — from 0.86 in 2024 to a central estimate of 1.2 (95% range 0.84–1.5). A 5-year backtest shows a typical error of ±16.8%, with 80% of held-out values landing inside the 95% band.

+37%Change by 2029
1.2Projected 2029 index
0.84–1.595% range
±16.8%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
20251.10.771.5
20261.10.791.5
20271.20.811.5
20281.20.821.5
20291.20.841.5

Routes In Great Basin

Routes recording Cassin's Vireo in Great Basin.
EwanWASHINGTON321995
Badger CreekOREGON212024
BartleCALIFORNIA142021
Davis LakeOREGON102024
E. Mt. AdamsWASHINGTON102024
Medicine Mtn.CALIFORNIA82021
Wizard FallsOREGON82024
PauninaOREGON72024
RimrockWASHINGTON72024
CarltonWASHINGTON72022
ChinchaloOREGON62024
HackamoreCALIFORNIA52010
SnowdenWASHINGTON52024
RonaldWASHINGTON52024
L. WenatcheeWASHINGTON52024
MacdoelCALIFORNIA42019
Camp ShermanOREGON41996
Bald Mtn.OREGON42024
LeavenworthWASHINGTON42024
PaisleyOREGON32024
NewhalemWASHINGTON32024
TwispWASHINGTON32024
ArdenvoirWASHINGTON31987
Blewett PassWASHINGTON32024
MazamaWASHINGTON32022

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