Molothrus bonariensis
Silhouette: Andy Wilson · PhyloPic
In 3 days ~90% in a week >90%
The shiny cowbird (Molothrus bonariensis) is a passerine bird in the New World family Icteridae. It breeds in most of South America except for dense forests and areas of high altitude such as mountains. Since 1900 the shiny cowbird's range has shifted northward, and it was recorded in the Caribbean islands as well as the United States, where it is found breeding in southern Florida. It is a bird associated with open habitats, including disturbed land from agriculture and deforestation.
Adults are sexually dimorphic. Males are all black with a purple-blue iridescence. The female is smaller, with dull brown plumage that is sometimes paler on the underparts. Females of the species can be distinguished from the female brown-headed cowbird by their longer, finer bills and flatter heads. The shiny cowbird's diet consists mainly of insects, other arthropods and seeds, and they have been recorded foraging for grains in cattle troughs.
Like most other cowbirds, it is an obligate brood parasite, laying its eggs in the nests of many other bird species such as the rufous-collared sparrow. Different host species show different responses to their nests being parasitised, with behaviours ranging from accepting and caring for the cowbird eggs, to rejecting the eggs from the nest. As the shiny cowbird is an effective generalist brood parasite, it can be considered the South American counterpart to the brown-headed cowbird. Wikipedia →
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Montevideo | 🇺🇾 Uruguay | |
| 2 | Mendoza | 🇦🇷 Argentina | |
| 3 | Santiago | 🇨🇱 Chile | |
| 4 | Asuncion | 🇵🇾 Paraguay | |
| 5 | Buenos Aires | 🇦🇷 Argentina | |
| 6 | Bogota | 🇨🇴 Colombia | |
| 7 | Curitiba | 🇧🇷 Brazil | |
| 8 | Cordoba | 🇦🇷 Argentina | |
| 9 | Brasilia | 🇧🇷 Brazil | |
| 10 | Rosario | 🇦🇷 Argentina |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Bioparque Wakatá | 🇨🇴 Colombia |
Likely
About 50% of wildlife watchers report a Shiny Cowbird sighting in Buenos Aires on a given day, based on 9,113 verified sightings from GBIF citizen-science data. It is the 16th most-seen of the 274 birds we can rate there. Over three days the chance rises to about 90%, and over a week to over 90%, if each day is a fresh chance.
October to December
In those months about 70% of wildlife watchers report a Shiny Cowbird in Buenos Aires on a given day, against about 30% in March, the lowest month.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Shiny 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 43
Of the 43 cities where we can rate Shiny Cowbird sightings, Buenos Aires ranks 5th at about 50%. The best odds are in Montevideo (Uruguay, about 60%), Mendoza (Argentina, about 60%) and Santiago (Chile, about 60%).
GBIF citizen-science records
It is estimated from how often the Shiny Cowbird is recorded against all the birds logged in Buenos Aires (9,113 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.
