Cistothorus platensis
Silhouette: Matt Wilkins · PhyloPic
In 3 days ~10% in a week ~20%
The grass wren (Cistothorus platensis) is a species of passerine bird in the family Troglodytidae. It is widely distributed in central and southern America. The grass wren was described in 1790 by the English ornithologist John Latham and given the binomial name Sylvia platensis. The type locality is Buenos Aires, Argentina. The current genus Cistothorus was introduced by the German ornithologist Jean Cabanis in 1850.
The grass wren and the sedge wren (Cistothorus stellaris) were formerly treated as conspecific. They were split based on the results of a molecular phylogenetic study published in 2014. This split was accepted in 2018 by the International Ornithological Committee (IOC) and BirdLife International's Handbook of the Birds of the World, in 2019 by the South American Classification Committee of the American Ornithological Society (AOS), and in 2021 by the AOS North American Classification Committee and the Clements taxonomy. As of 2018 the fourth edition of the Howard and Moore Complete Checklist of the Birds of the World had not implemented the split. Taxonomic bodies recognize 17 subspecies of the grass wren.
The grass wren... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Los Nevados National Natural Park | 🇨🇴 Colombia | |
| 2 | Serra da Canastra National Park | 🇧🇷 Brazil | |
| 3 | Chingaza National Natural Park | 🇨🇴 Colombia | |
| 4 | Riding Mountain National Park | 🇨🇦 Canada | |
| 5 | Emas National Park | 🇧🇷 Brazil | |
| 6 | Torres del Paine National Park | 🇨🇱 Chile | |
| 7 | Tierra del Fuego National Park | 🇦🇷 Argentina | |
| 8 | Voyageurs National Park | 🇺🇸 United States | |
| 9 | Padre Island National Seashore | 🇺🇸 United States | |
| 10 | Nahuel Huapi National Park | 🇦🇷 Argentina | |
| 11 | Point Pelee National Park | 🇨🇦 Canada | |
| 12 | Congaree National Park | 🇺🇸 United States | |
| 13 | Merritt Island National Wildlife Refuge | 🇺🇸 United States | |
| 14 | Big Cypress National Preserve | 🇺🇸 United States | |
| 15 | La Tigra National Park | 🇭🇳 Honduras | |
| 16 | Everglades National Park | 🇺🇸 United States | |
| 17 | Braulio Carrillo National Park | 🇨🇷 Costa Rica | |
| 18 | Iberá National Park | 🇦🇷 Argentina | |
| 19 | Farallones de Cali National Natural Park | 🇨🇴 Colombia |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Quito | 🇪🇨 Ecuador | |
| 2 | Mexico City | 🇲🇽 México | |
| 3 | Chicago | 🇺🇸 United States | |
| 4 | Houston | 🇺🇸 United States | |
| 5 | Dallas | 🇺🇸 United States | |
| 6 | San Antonio | 🇺🇸 United States | |
| 7 | Toronto | 🇨🇦 Canada | |
| 8 | Minneapolis [Saint Paul] | 🇺🇸 United States | |
| 9 | Orlando | 🇺🇸 United States | |
| 10 | Washington | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Grass Wren sighting in Tierra del Fuego National Park on a given day, based on 39 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 56th most-seen of the 78 birds we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.
February–April and October
In those months about 10% of wildlife watchers report a Grass Wren in Tierra del Fuego National Park on a given day, against under 5% in May, July–September and November–January, the lowest months. June has too few records to rate.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Grass Wren sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
7th of 19
Of the 19 parks where we can rate Grass Wren sightings, Tierra del Fuego National Park ranks 7th at under 5%. The best odds are in Los Nevados National Natural Park (Colombia, about 30%), Serra da Canastra National Park (Brazil, about 30%) and Chingaza National Natural Park (Colombia, about 20%).
GBIF citizen-science records
It is estimated from how often the Grass Wren is recorded against all the birds logged in Tierra del Fuego National Park (39 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.
