Cardellina pusilla
Silhouette: Andy Wilson · PhyloPic
In 3 days ~20% in a week ~40%
Wilson's warbler (Cardellina pusilla) is a small New World warbler. It is greenish above and yellow below, with rounded wings and a long, slim tail. The male has a black crown patch; depending on the subspecies, that mark is reduced or absent in the female. It breeds across Canada and south through the western United States, and winters from Mexico south through much of Central America. It is a very rare vagrant to western Europe.
Wilson's warbler was formally described in 1811 by the ornithologist Alexander Wilson under the binomial name Muscicapa pusilla. The type locality is southern New Jersey. The species was moved to the genus Wilsonia by the naturalist and ornithologist Charles Lucien Bonaparte in 1838. Zoologist Thomas Nuttall moved it to Sylvania in 1840, and by 1845, many authors included it in Myiodioctes. In 1899, the American Ornithological Union returned the species to Wilsonia. The species is currently assigned to the genus Cardellina. The genus name Cardellina is a diminutive of the Italian dialect Cardella, a name for the European goldfinch, and the specific epithet pusilla means "very small".
There are three recognized subspecies: Wikipedia →
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Toluca | 🇲🇽 México | |
| 2 | Puebla | 🇲🇽 México | |
| 3 | Mexico City | 🇲🇽 México | |
| 4 | Guadalajara | 🇲🇽 México | |
| 5 | León | 🇲🇽 México | |
| 6 | Monterrey | 🇲🇽 México | |
| 7 | Guatemala City | 🇬🇹 Guatemala | |
| 8 | Torreón | 🇲🇽 México | |
| 9 | Tijuana | 🇲🇽 México | |
| 10 | Vancouver | 🇨🇦 Canada |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Zoológico de Culiacán | 🇲🇽 Mexico |
With luck
About 10% of wildlife watchers report a Wilson's Warbler sighting in Saguaro National Park on a given day, based on 474 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 58th most-seen of the 220 birds we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
September
In that month about 30% of wildlife watchers report a Wilson's Warbler in Saguaro National Park on a given day, against under 5% in June–July and November–March, the lowest months. That is one of Saguaro National Park's wettest months, with about 50 mm of rain against almost none in May.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Wilson's Warbler sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
43rd of 63
Of the 63 parks where we can rate Wilson's Warbler sightings, Saguaro National Park ranks 43rd at about 10%. The best odds are in Irazú Volcano National Park (Costa Rica, about 70%), Los Quetzales National Park (Costa Rica, about 50%) and Volcán Barú National Park (Panama, about 50%). All parks ranked.
Same family: Parulidae
The closest relatives of the Wilson's Warbler that you can see in Saguaro National Park (family Parulidae, New World Warblers) are Lucy's Warbler (about 20%), Yellow-rumped Warbler (about 20%) and Yellow Warbler (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Wilson's Warbler is recorded against all the birds logged in Saguaro National Park (474 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.
