Brown-headed Cowbird
(Molothrus ater)
Adult Male
(Molothrus ater)
Adult Male
Male
Female
Brown-Headed Cowbirds are small, sparrow sized birds. Males have a glossy black body and bill with a brown head (can be dull or glossy). Females have a dull light brown that covers the entirety of their body. Females also have darker wings and a tail. Both the male and the female can have a white, beige, or light colored throats. Juveniles look like females with some streaking.
Male song is a loud CHI-DUINK and/or KA-DEENK. Both the male and female produce a harsh trill that slows at the end: KKKIKIKIKIKI-KI-KI. They also make “Kep” and “Seer” calls (similar to the Red-Winged Blackbird). Juv. Will emit soft, scratchy chips, occasionally with two syllables. .
The Brown-headed Cowbird's CHI-DUINK call made while perching on wire with Cowbird seer call in the background.
This is the KA-DEENK call of the Brown-headed Cowbird. Notice how with both calls the Cowbird inflates their feathers starting before the call, reaching a climax while calling, then deflating rapidly after.
This juvenile is being raised by a Song Sparrow, and emits CHE calls, sometimes two syllabled, possibly to get attention.
Brown-Headed Cowbirds spend most of their time in open areas. This includes open forests, forest edge, scrublands, brushy fields, fields, soccer fields, and suburbia. They are mostly seen in open forest, forest edge, and fields.
Brown-Headed Cowbirds gather in small flocks (usually from 3-10) and forage. While foraging, they seem to turn their head up, likely to scan the sky for predators.
Cowbird females, like cuckoos, will lay eggs in other bird’s nests. This is called brood parasitism. Often the baby cowbird will outcompete the host chicks, and the host bird will raise only the cowbird chick to adulthood.
Common Grackles can be easily differentiated by their larger size, yellow eye color (but with a black pupil), longer and more decurved bill shape, and longer tapering tail shape. Common Grackles are also more adaptable to habitats, so they are more likely to be seen in a forest than a Cowbird.
The males of both species can be differentiated by the color of their median coverts (Red-wing has yellow and red median coverts, while the cowbird has a black one), size ( R.W. blackbirds are larger), and bill shape ( R.W. blackbirds is longer). Female Red-wings have darker striping than the Juv. and female Brown-headed Cowbird.
Adult starlings look a lot like a male cowbird, but note the longer bill (yellow bill in summer) and black head. Juv. Starlings look like females and Juv. Cowbirds, but they have longer bills and walk like a penguin (waddling). Juv. Starlings are sometimes darker. Juv. Starlings and adult starlings also have different calls that sound like metallic gurgling.
Female House Sparrow
Female House Sparrows look like female cowbirds, but note that the sparrow has streaking on the back, a pale bill, and a light supercilium (eyebrow). They also have different calls, the sparrow making harsh chirps instead of trills and "kep"s.
They are best seen at the edges of fields at Bluemont Park in late winter to early spring. They will gather in small flocks at the edge of trees next to the baseball field (usually not in use) To forage. They are also seen around the entrance of Arlington Forest Park and the surrounding suburbs.