Vireo philadelphicus
Silhouette: Caleb Gordon · PhyloPic
In 3 days ~20% in a week ~50%
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 |
With luck
About 10% of wildlife watchers report a Philadelphia Vireo sighting in San José on a given day, based on 1,566 verified sightings from GBIF citizen-science data. It is the 54th most-seen of the 379 birds we can rate there. Over three days the chance rises to about 20%, and over a week to about 50%, if each day is a fresh chance.
March and December–January
In those months about 20% of wildlife watchers report a Philadelphia Vireo in San José on a given day, against under 5% in May to October, the lowest months. Those are among San José's driest months, with about 45 mm of rain a month against 300 mm in October.
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.
Yes
Of the 25 cities where we can rate Philadelphia Vireo sightings, San José has the highest daily chance: about 10%. Next come Chicago (United States, under 5%) and Tegucigalpa (Honduras, under 5%).
Same genus: Vireo
The closest relatives of the Philadelphia Vireo that you can see in San José (genus Vireo, Vireos) are Yellow-green Vireo (about 10%), Yellow-throated Vireo (about 10%) and Red-eyed Vireo (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Philadelphia Vireo is recorded against all the birds logged in San José (1,566 verified sightings), 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.
