Vireo bellii
Silhouette: Caleb Gordon · PhyloPic
In 3 days ~40% in a week ~70%
Bell's vireo (Vireo bellii) is a songbird that migrates between a breeding range in Western North America and a winter range in Central America. It is dull olive-gray above and whitish below. It has a faint white eye ring and faint wing bars.
This bird was named by Audubon for John Graham Bell, who accompanied him on his trip up the Missouri River in the 1840s. The least Bell's vireo (Vireo bellii pusillus) is an endangered subspecies in Southern California. Consideration of Bell's vireo has been a factor in several land development projects, to protect least Bell's vireo habitat. The decline of the least Bell's vireo is mostly due to a loss of riparian habitat.
Measurements: Length: 4.5–4.9 in (11.5–12.5 cm) Weight: 0.3–0.3 oz (7.4–9.8 g) Wingspan: 6.7–7.5 in (17–19 cm) Least Bell's vireo, V.b. pusillus (southern California) Arizona Bell's vireo, V.b. arizonae (southwestern United States, northern Mexico)
V.b. medius (southwestern Texas, Mexico) V.b. belli (central and midwestern United States to central Mexico) In its breeding range, Bell's vireo often uses dense shrubbery in riparian areas or otherwise near water. Willow... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Big Bend National Park | 🇺🇸 United States | |
| 2 | Saguaro National Park | 🇺🇸 United States | |
| 3 | Death Valley National Park | 🇺🇸 United States | |
| 4 | Cabo Pulmo National Park | 🇲🇽 Mexico | |
| 5 | Badlands National Park | 🇺🇸 United States | |
| 6 | Guadalupe Mountains National Park | 🇺🇸 United States | |
| 7 | Cumbres de Monterrey National Park | 🇲🇽 Mexico | |
| 8 | Bahía de Loreto National Park | 🇲🇽 Mexico | |
| 9 | El Vizcaíno Biosphere Reserve | 🇲🇽 Mexico | |
| 10 | Zion National Park | 🇺🇸 United States | |
| 11 | Point Pelee National Park | 🇨🇦 Canada | |
| 12 | Channel Islands National Park | 🇺🇸 United States | |
| 13 | Grand Canyon National Park | 🇺🇸 United States | |
| 14 | Everglades National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Los Angeles | 🇺🇸 United States | |
| 2 | Monterrey | 🇲🇽 México | |
| 3 | San Diego | 🇺🇸 United States | |
| 4 | Mesa | 🇺🇸 United States | |
| 5 | San Antonio | 🇺🇸 United States | |
| 6 | Austin | 🇺🇸 United States | |
| 7 | Dallas | 🇺🇸 United States | |
| 8 | Phoenix | 🇺🇸 United States | |
| 9 | Houston | 🇺🇸 United States | |
| 10 | Mexico City | 🇲🇽 México |
With luck
About 10% of wildlife watchers report a Bell's Vireo sighting in Saguaro National Park on a given day, based on 1,086 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 39th most-seen of the 220 birds we can rate there. Over three days the chance rises to about 40%, and over a week to about 70%, if each day is a fresh chance.
April to June
In those months about 30% of wildlife watchers report a Bell's Vireo in Saguaro National Park on a given day, against under 5% in October to February, the lowest months. Those are among Saguaro National Park's driest months, with about 5 mm of rain a month against 55 mm in July.
Between 7 and 10 am
Across all the parks we cover, that three-hour window holds the most Bell's Vireo sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
2nd of 14
Of the 14 parks where we can rate Bell's Vireo sightings, Saguaro National Park ranks 2nd at about 10%. The best odds are in Big Bend National Park (United States, about 40%).
GBIF citizen-science records
It is estimated from how often the Bell's Vireo is recorded against all the birds logged in Saguaro National Park (1,086 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
