Molothrus ater
Silhouette: Andy Wilson · PhyloPic
In 3 days ~50% in a week ~80%
The brown-headed cowbird (Molothrus ater) is a small, obligate brood parasitic icterid native to temperate and subtropical North America. It is a permanent resident in the southern parts of its range; northern birds migrate to the southern United States and Mexico in winter, returning to their summer habitat around March or April.
The brown-headed cowbird was described by the French polymath Georges-Louis Leclerc, Comte de Buffon in 1775 in his Histoire Naturelle des Oiseaux from a specimen collected in the Carolinas. The bird was also illustrated in a hand-colored plate engraved by François-Nicolas Martinet in the Planches Enluminées D'Histoire Naturelle, which was produced under the supervision of Edme-Louis Daubenton to accompany Buffon's text. Neither the plate caption nor Buffon's description included a scientific name, but in 1783, Dutch naturalist Pieter Boddaert coined the binomial name Oriolus ater in his catalogue of the Planches Enluminées. The brown-headed cowbird is now placed in the genus Molothrus that was introduced by English naturalist William Swainson in 1832 with the brown-headed cowbird as the type species. The genus name combines the Ancient Greek... Wikipedia →
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | León | 🇲🇽 México | |
| 2 | Detroit | 🇺🇸 United States | |
| 3 | Chicago | 🇺🇸 United States | |
| 4 | Baltimore | 🇺🇸 United States | |
| 5 | Washington | 🇺🇸 United States | |
| 6 | Mesa | 🇺🇸 United States | |
| 7 | Philadelphia | 🇺🇸 United States | |
| 8 | Toronto | 🇨🇦 Canada | |
| 9 | Minneapolis [Saint Paul] | 🇺🇸 United States | |
| 10 | Dallas | 🇺🇸 United States |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Columbus Zoo and Aquarium | 🇺🇸 United States | |
| 2 | Omaha’s Henry Doorly Zoo and Aquarium | 🇺🇸 United States | |
| 3 | Ralph Perkins II Wildlife Center and Woods Garden | 🇺🇸 United States |
Possible
About 20% of wildlife watchers report a Brown-headed Cowbird sighting in Yosemite National Park on a given day, based on 794 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 38th most-seen of the 169 birds we can rate there. Over three days the chance rises to about 50%, and over a week to about 80%, if each day is a fresh chance.
May
In that month about 40% of wildlife watchers report a Brown-headed Cowbird in Yosemite National Park on a given day, against under 5% in March and September–December, the lowest months. That is one of Yosemite National Park's driest months, with about 50 mm of rain against 220 mm in January.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Brown-headed Cowbird sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
7th of 37
Of the 37 parks where we can rate Brown-headed Cowbird sightings, Yosemite National Park ranks 7th at about 20%. The best odds are in Point Pelee National Park (Canada, about 60%), Badlands National Park (United States, about 40%) and Elk Island National Park (Canada, about 30%). All parks ranked.
Same family: Icteridae
The closest relatives of the Brown-headed Cowbird that you can see in Yosemite National Park (family Icteridae, New World Blackbirds and Orioles) are Brewer's Blackbird (about 40%), Red-winged Blackbird (about 30%) and Bullock's Oriole (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Brown-headed Cowbird is recorded against all the birds logged in Yosemite National Park (794 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.
