Setophaga pensylvanica
Silhouette: Dylan GE Gomes · PhyloPic
In 3 days <5% in a week ~10%
The chestnut-sided warbler (Setophaga pensylvanica) is a New World warbler. They breed in eastern North America and in southern Canada westwards to the Canadian Prairies. They also breed in the Great Lakes region and in the eastern United States.
The chestnut-sided warbler was formally described in 1766 by the Swedish naturalist Carl Linnaeus in the twelfth edition of his Systema Naturae under the binomial name Motacilla pensylvanica. Linnaeus based his account on the "Red-throated fly-catcher" that had been described and illustrated in 1760 by the English naturalist George Edwards in his book Gleanings of Natural History. Edwards had received specimens from the American naturalist William Bartram that had been collected in Pennsylvania. The chestnut-sided warbler is now one of more than 30 species placed in the genus Setophaga that was introduced in 1827 by the English naturalist William Swainson. The genus name Setophaga combines the Ancient Greek σης/sēs, σητος/sētos meaning "moth" with -φαγος/-phagos meaning "-eating". The species is monotypic: no subspecies are recognised.
Setophaga icterocephala is a junior synonym of S. pennsylvanicus, and is no longer used. The... Wikipedia →
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Chicago | 🇺🇸 United States | |
| 2 | San José | 🇨🇷 Costa Rica | |
| 3 | New York City | 🇺🇸 United States | |
| 4 | Minneapolis [Saint Paul] | 🇺🇸 United States | |
| 5 | Toronto | 🇨🇦 Canada | |
| 6 | Detroit | 🇺🇸 United States | |
| 7 | San Pedro Sula | 🇭🇳 Honduras | |
| 8 | Baltimore | 🇺🇸 United States | |
| 9 | Montreal | 🇨🇦 Canada | |
| 10 | Houston | 🇺🇸 United States |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Sea Life Aquarium | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Chestnut-sided Warbler sighting in Irazú Volcano National Park on a given day, based on 8 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 110th most-seen of the 121 birds we can rate there. Over three days the chance rises to under 5%, and over a week to about 10%, if each day is a fresh chance.
April
In that month about 10% of wildlife watchers report a Chestnut-sided Warbler in Irazú Volcano National Park on a given day, against under 5% in May to March, the lowest months.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Chestnut-sided 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.
50th of 62
Of the 62 parks where we can rate Chestnut-sided Warbler sightings, Irazú Volcano National Park ranks 50th at under 5%. The best odds are in Arenal Volcano National Park (Costa Rica, about 50%), Riding Mountain National Park (Canada, about 40%) and Tenorio Volcano National Park (Costa Rica, about 40%). All parks ranked.
Same genus: Setophaga
The closest relatives of the Chestnut-sided Warbler that you can see in Irazú Volcano National Park (genus Setophaga, Setophaga Warblers) are Black-throated Green Warbler (about 30%), Blackburnian Warbler (about 10%) and Townsend's Warbler (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Chestnut-sided Warbler is recorded against all the birds logged in Irazú Volcano National Park (8 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.
