Shiny Cowbird or Bronzed Cowbird ?

Song

Audio by Paul Marvin

There's more to learn about Shiny Cowbird

Bronzed Cowbird

Molothrus aeneus

How to recognise a bronzed cowbird?

General appearance

Meet the bronzed cowbird, a dynamic marvel in the bird world! Flaunting an innate fashion sense, this bird adorns a full-bodied, glossy black-plumaged coat that varies from dark to shimmering bronzed-brown. It's renowned for the blazing red eyes that contrast attractively with its overall dark exterior. Defined and distinct, their robust bill and large stature separate them from other cowbird types.

Male vs female

While both sexes of bronzed cowbirds carry an air of mystery with their dashing black feathers and vivacious eyes, males step up their look! They appear larger, more intimidating, with a pronounced gloss of tawny bronze. Still, our ladies are not left behind; they have a subtle charm, being slightly smaller with a less glossy, but still beautiful brownish-black plumage. Each sex carries its distinctive flair to the bird party!

Juvenile

The juveniles tag along, less flashy but insistently noticeable. They are a duller brown than the adult female and do not yet possess the iconic piercing red eyes. Instead, their eyes take a more relaxed gray-brown shade. But hold on tight, though less showy, these young cowbirds evolve into their striking adult colors as they mature. So, spotting a bronzed cowbird chick could mean being an audience to an unforgettable transformation!

Size

7.5 - 8.3 in/1.9 - 2.5 oz

Habitat

Primary habitat

The bronzed cowbird generally prefers very open habitats in lowlands such as farmland, semi-open country, and areas around cattle feedlots. It also roosts in brushy woods.

Additional range

During the breeding season, this bird wanders widely, adopting a larger range of habitats including forest edges, deserts, and open woods in mountains.

Range Map

What do bronzed cowbirds like to eat?

Natural diet

The bronzed cowbird primarily consumes seeds, focusing on those from grasses and weeds, as well as waste grain. Occasionally, it includes berries in its diet. It is also known to eat various insects such as caterpillars, beetles, flies, and others. Snails and spiders are part of their diet as well. Notably, female bronzed cowbirds may rely on snails for calcium, especially when laying eggs.

Bird feeders

At bird feeders, bronzed cowbirds might consume seeds typically offered, such as sunflower seeds or millet, which are popular choices in many feeders. However, their specific preference at feeders is not as documented as their natural diet.

What does a bronzed cowbird sound like?

The vocalizations of the bronzed cowbird are a unique array of sounds that include wheezy and guttural whistling notes, and a variety of squeaks and squeals. Their call pattern is rising, creating an almost crescendo effect. Their dominant call type is high-pitched, resembling a whistle. This call pattern and type define their distinctive songs and calls.

Call

Audio by Paul Marvin

Call

Audio by Paul Marvin

There's more to learn about Bronzed Cowbird

Shiny Cowbird

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Bronzed Cowbird

Shiny Cowbird

Molothrus bonariensis

General appearance

The shiny cowbird is a small, compact bird with a slender build and short tail. It typically measures about 18-20 cm in length. The species is characterized by a sharp, conical bill and relatively long legs, making it well-adapted for its perching lifestyle. The bird's plumage is typically glossy and has an iridescent quality, especially in good lighting.

Male vs female

Male shiny cowbirds are strikingly glossy with a deep purple to black sheen that catches the light and appears shiny. In contrast, females are less visually stunning, with duller brownish plumage that can occasionally have faint streaks; this more subdued coloration helps them blend into their surroundings. Both genders have similar body shapes, but these coloration differences are the most distinctive feature between them.

Juvenile

Juvenile shiny cowbirds resemble females but are even less glossy, with more muted brown feathers and often with streaks or speckles. Their plumage lacks the iridescent sheen seen in adults, making them harder to identify from afar. Juveniles can sometimes appear somewhat scruffy as they transition to adult plumage over successive molts.

Size

6.7 - 8.7 in/1.1 - 2.3 oz

There's more to learn about Shiny Cowbird

Bronzed Cowbird

Molothrus aeneus

General appearance

Meet the bronzed cowbird, a dynamic marvel in the bird world! Flaunting an innate fashion sense, this bird adorns a full-bodied, glossy black-plumaged coat that varies from dark to shimmering bronzed-brown. It's renowned for the blazing red eyes that contrast attractively with its overall dark exterior. Defined and distinct, their robust bill and large stature separate them from other cowbird types.

Male vs female

While both sexes of bronzed cowbirds carry an air of mystery with their dashing black feathers and vivacious eyes, males step up their look! They appear larger, more intimidating, with a pronounced gloss of tawny bronze. Still, our ladies are not left behind; they have a subtle charm, being slightly smaller with a less glossy, but still beautiful brownish-black plumage. Each sex carries its distinctive flair to the bird party!

Juvenile

The juveniles tag along, less flashy but insistently noticeable. They are a duller brown than the adult female and do not yet possess the iconic piercing red eyes. Instead, their eyes take a more relaxed gray-brown shade. But hold on tight, though less showy, these young cowbirds evolve into their striking adult colors as they mature. So, spotting a bronzed cowbird chick could mean being an audience to an unforgettable transformation!

Size

7.5 - 8.3 in/1.9 - 2.5 oz

There's more to learn about Bronzed Cowbird

How to tell the Shiny Cowbird from the Bronzed Cowbird

Visual differences

The Shiny Cowbird is smaller (approx. 7-8 inches) with a slender build and a sharp, conical bill. Males have a glossy, deep purple-black sheen, while females are brownish. In contrast, the Bronzed Cowbird is slightly larger (approx. 7.5-8.5 inches) with a robust bill and striking red eyes. Males feature glossy black plumage with a bronzed gloss, and females display brownish-black feathers. Juveniles of both species are duller, but Bronzed juveniles lack the distinctive red eyes initially.

Key differences and behavior

Shiny Cowbirds (Molothrus bonariensis) and Bronzed Cowbirds (Molothrus aeneus) are both brood parasites, laying eggs in other birds' nests, but differ in behavior and habitat. Shiny Cowbirds thrive in semi-open areas, especially coastal lawns in North America, and exhibit unique preening behaviors. They eat insects and seeds, with little known about their feeder habits. Males sing and display to attract females during breeding. In contrast, Bronzed Cowbirds prefer very open lowlands, farmlands, and brushy woods, showing elaborate displays where males puff feathers and vibrate wings. They consume seeds, waste grain, and insects. Bronzed Cowbirds are larger (55-70g, 19-21in) than Shiny Cowbirds (31-65g, 17-22in) and use a variety of over 101 host species to raise their young.

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