Cassin's Vireo
Vireo cassinii
- KingdomAnimalia (Animals)
- PhylumChordata (Chordates)
- ClassAves (Birds)
- OrderPasseriformes (Perching Birds)
- FamilyVireonidae (Vireos, Shrike-Babblers, and Erpornis)
- GenusVireo (Vireos)
- SpeciesVireo cassinii (Cassin's Vireo)
About the Cassin's Vireo
Cassin's vireo (Vireo cassinii) is a small North American songbird, ranging from southern British Columbia in Canada through the western coastal states of the United States, including California, Oregon, and Washington. The Cassin's Vireo moves down Western United States forests in its migration. During its migration in early spring and late fall, it spends the winter in regions from southern Arizona (the Sonoran Desert) to southern Mexico, including parts of Baja California and the Pacific coast of Mexico.
The vireo is 11–14 cm (4–6 inches) long. It has a grayish olive head, back, and flanks, with whitish underparts. One of its distinctive features is the solid white "spectacles" around its eyes, along with white wing bars. These markings set it apart from other similar species like the plumbeous vireo and the blue-headed vireo.
Cassin's vireo is known for its persistent song, which consists of short, rough-whistled phrases of several notes.These phrases are 2 seconds apart and often alternate between ending on high and low notes, creating a "question-and-answer" pattern. The Cassin's Vireo is known to sing for an extensive duration of time. Hearing... Wikipedia →
Closest Relatives at Saguaro National Park
Bell's Vireo
Vireo bellii
Plumbeous Vireo
Vireo plumbeus
Warbling Vireo
Vireo gilvus
White-eyed Vireo
Vireo griseus
Hutton's Vireo
Vireo huttoni
Gray Vireo
Vireo vicinior
Blue-headed Vireo
Vireo solitarius
Red-eyed Vireo
Vireo olivaceus
Philadelphia Vireo
Vireo philadelphicus
Verdin
Auriparus flaviceps
House Finch
Haemorhous mexicanus
Lesser Goldfinch
Spinus psaltria
Global Distribution
Where this species is recorded worldwide. Restricted to human observations from 2019 onwards — the same kind of record and the same period the probabilities on this page are built from, so collar-tracking studies, camera-trap arrays and museum specimens are excluded. Around Santa Rosa that removes 5,924 GPS fixes from a handful of tagged jaguars.
where this species is recorded (GBIF density — it tracks where observers go, not how likely a sighting is) · parks where it occurs — tap a pin for the sighting probability there
Parks Where Found
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Yosemite National Park | 🇺🇸 United States | |
| 2 | Glacier National Park | 🇺🇸 United States | |
| 3 | Jasper National Park | 🇨🇦 Canada | |
| 4 | Sequoia and Kings Canyon National Parks | 🇺🇸 United States | |
| 5 | Banff National Park | 🇨🇦 Canada | |
| 6 | Death Valley National Park | 🇺🇸 United States | |
| 7 | Zion National Park | 🇺🇸 United States | |
| 8 | Big Bend National Park | 🇺🇸 United States | |
| 9 | Great Bear Rainforest | 🇨🇦 Canada | |
| 10 | Saguaro National Park | 🇺🇸 United States | |
| 11 | Guadalupe Mountains National Park | 🇺🇸 United States | |
| 12 | Redwood National Park | 🇺🇸 United States | |
| 13 | Grand Canyon National Park | 🇺🇸 United States | |
| 14 | Olympic National Park | 🇺🇸 United States | |
| 15 | Joshua Tree National Park | 🇺🇸 United States | |
| 16 | Grand Teton National Park | 🇺🇸 United States | |
| 17 | Rocky Mountain National Park | 🇺🇸 United States | |
| 18 | Channel Islands National Park | 🇺🇸 United States | |
| 19 | Reserva de la Biosfera Mariposa Monarca | 🇲🇽 Mexico | |
| 20 | Yellowstone National Park | 🇺🇸 United States |
Quick answers
What are the chances of seeing a Cassin's Vireo in Saguaro National Park?
Under 5% of wildlife watchers report a Cassin's Vireo sighting in Saguaro National Park, based on 939 verified sightings from GBIF citizen-science data.
When is the best time to see Cassin's Vireo in Saguaro National Park?
April has the highest sighting rate for Cassin's Vireo in Saguaro National Park in our monthly data.