Molothrus rufoaxillaris
Silhouette: Andy Wilson · PhyloPic
In 3 days ~10%
The screaming cowbird (Molothrus rufoaxillaris) is an obligate brood parasite belonging to the family Icteridae and is found in South America. It is also known commonly as the short billed cowbird. The screaming cowbird has mildly iridescent black plumage; the lesser under-wing coverts are rufous. The female is slightly duller in colour than the male. The legs are black and the iris is reddish brown. Adult body length is 18–21 cm and mean adult weight is 58 g for males and 48 g for females. The call of the screaming cowbird was first described as "impetuous screaming notes"; however, a more useful description for field identification is noisy, explosive and piercing with rasp-like calls also produced. Screaming cowbirds are mostly seen in pairs or small flocks.
Within South America, the screaming cowbird is found in north east and central Argentina, south east Bolivia, central Brazil and throughout Paraguay and Uruguay. Its natural habitat is pastureland where it forages amongst grazing animals such as cows, hence the name "cowbird". Similar to other cowbirds, it forages predominantly on the ground, eating invertebrates that have been... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Iberá National Park | 🇦🇷 Argentina | |
| 2 | El Palmar National Park | 🇦🇷 Argentina | |
| 3 | Emas National Park | 🇧🇷 Brazil | |
| 4 | El Impenetrable National Park | 🇦🇷 Argentina | |
| 5 | Chapada dos Guimarães National Park | 🇧🇷 Brazil | |
| 6 | Serra da Canastra National Park | 🇧🇷 Brazil | |
| 7 | Iguaçu National Park | 🇧🇷 Brazil | |
| 8 | Iguazú National Park | 🇦🇷 Argentina |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Cordoba | 🇦🇷 Argentina | |
| 2 | Buenos Aires | 🇦🇷 Argentina | |
| 3 | Rosario | 🇦🇷 Argentina | |
| 4 | Mendoza | 🇦🇷 Argentina | |
| 5 | Montevideo | 🇺🇾 Uruguay | |
| 6 | Asuncion | 🇵🇾 Paraguay | |
| 7 | Santa Cruz de la Sierra | 🇧🇴 Bolivia | |
| 8 | Porto Alegre | 🇧🇷 Brazil | |
| 9 | Santiago | 🇨🇱 Chile | |
| 10 | Curitiba | 🇧🇷 Brazil |
Rare
Under 5% of wildlife watchers report a Screaming Cowbird sighting in Chapada dos Guimarães National Park on a given day, based on 16 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 197th most-seen of the 273 birds we can rate there. Over three days the chance rises to about 10%, if each day is a fresh chance.
November and December
In those months about 10% of wildlife watchers report a Screaming Cowbird in Chapada dos Guimarães National Park on a given day, against under 5% in January and May–October, the lowest months. Those are among Chapada dos Guimarães National Park's wettest months, with about 180 mm of rain a month against almost none in July. February to April have too few records to rate.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Screaming Cowbird sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
5th of 8
Of the 8 parks where we can rate Screaming Cowbird sightings, Chapada dos Guimarães National Park ranks 5th at under 5%. The best odds are in Iberá National Park (Argentina, about 10%), El Palmar National Park (Argentina, about 10%) and Emas National Park (Brazil, under 5%).
Same genus: Molothrus
The closest relatives of the Screaming Cowbird that you can see in Chapada dos Guimarães National Park (genus Molothrus, Cowbirds) are Shiny Cowbird (about 30%) and Giant Cowbird (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Screaming Cowbird is recorded against all the birds logged in Chapada dos Guimarães National Park (16 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.
