Vireo philadelphicus
Silhouette: Caleb Gordon · PhyloPic
In 3 days ~10% in a week ~30%
The Philadelphia vireo (Vireo philadelphicus) is a small North American songbird in the vireo family (Vireonidae). "Vireo" is a Latin word referring to a green migratory bird, perhaps the female golden oriole, possibly the European greenfinch. The specific philadelphicus is for the city of Philadelphia.
Adults are mainly olive-brown on the upperparts with yellow underparts; they have dark eyes and a grey crown. They have no wing bars and no eye ring. There is a dark line through the eyes and a white stripe just over them. They have thick blue-grey legs and a stout bill. The Philadelphia vireo is similar in appearance to the warbling vireo, but can be reliably distinguished by having much yellower underparts, and dark lores.
Their breeding habitat is the edges of deciduous and mixed woods across Canada. They make a basket-shaped cup nest in a fork of a tree branch, usually placed relatively high. The female lays 3 to 5 lightly spotted white eggs. Incubation, by both parents, lasts up to 14 days.
These birds migrate to Mexico and Central America. This vireo is a very rare vagrant to western Europe. They are unlikely to visit Philadelphia, except in migration... Wikipedia →
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | San José | 🇨🇷 Costa Rica | |
| 2 | Chicago | 🇺🇸 United States | |
| 3 | Tegucigalpa | 🇭🇳 Honduras | |
| 4 | Toronto | 🇨🇦 Canada | |
| 5 | Detroit | 🇺🇸 United States | |
| 6 | Montreal | 🇨🇦 Canada | |
| 7 | Houston | 🇺🇸 United States | |
| 8 | Edmonton | 🇨🇦 Canada | |
| 9 | Minneapolis [Saint Paul] | 🇺🇸 United States | |
| 10 | Austin | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Philadelphia Vireo sighting in Gros Morne National Park on a given day, based on 52 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 82nd most-seen of the 130 birds we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
June
In that month about 10% of wildlife watchers report a Philadelphia Vireo in Gros Morne National Park on a given day, against under 5% in July to May, the lowest months.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Philadelphia Vireo sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
21st of 53
Of the 53 parks where we can rate Philadelphia Vireo sightings, Gros Morne National Park ranks 21st at under 5%. The best odds are in Santa Rosa National Park (Costa Rica, about 20%), Rincón de la Vieja National Park (Costa Rica, about 20%) and Chirripó National Park (Costa Rica, about 10%).
GBIF citizen-science records
It is estimated from how often the Philadelphia Vireo is recorded against all the birds logged in Gros Morne National Park (52 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.
