Bronzed Cowbird vs Common Grackle

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

/ CC BY-NC-SA 4.0

Call

Audio by Paul Marvin

/ CC BY-NC-SA 4.0

There's more to learn about Bronzed Cowbird

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Common Grackle

Quiscalus quiscula

Also known as: Blackbird

How to recognise a common grackle?

General appearance

The common grackle is about the size of a crow, bearing a distinctive long tail with a crease down the middle. Coloring varies with two forms presented, namely, the 'Bronzed Grackle' and the 'Purple Grackle.' The former spots a bronzy body offset by a blue-black head while the latter shines with glosses of purple and green, offering less contrast.

Male vs female

Physical variations between the sexes are not explicitly stated. However, based on the Bronzed and Purple forms noted, it could be inferred that some slight difference in color intensity and gloss may exist.

Juvenile

Juvenile grackles present dark eyes in contrast to the whitish-yellow eye color observed in adults. Molting, a period prevalent in late summer, results in these younger birds having short or fragmented tails.

Size

11.0 - 13.4 in/2.6 - 5.0 oz

Habitat

Primary habitat

Common grackles are often found in open or semi-open landscapes such as farmland, pastures, suburban lawns and towns. They tend to nest and roost in places with dense coniferous trees near open areas.

Additional range

Beyond typical rural and suburban settings, these birds can also be found foraging in cattle feedlots and marshes, and residing on the edges of woodlands and in parks.

Range Map

What do common grackles like to eat?

Natural diet

The common grackle is an omnivorous bird, feeding on a wide variety of items. Its natural diet includes insects like beetle grubs, grasshoppers, and caterpillars, as well as spiders, millipedes, and earthworms. It also consumes crayfish, minnows, frogs, lizards, eggs and young of other birds, and small rodents. In addition to animal prey, the grackle eats vegetable matter, which becomes more dominant in its diet during winter. This includes berries, seeds, waste grain, and acorns.

Bird feeders

At bird feeders, common grackles often consume seeds such as sunflower seeds and cracked corn. They are known to be aggressive at feeders and may also eat suet and peanuts, taking advantage of the variety of offerings typically available at these feeding stations.

What does a common grackle sound like?

The common grackle frequently produces a clucking sound. Its signature vocalization is a high-pitched rising screech reminiscent of a rusty hinge, a memorable, abrasive sound. The grackle's call varieties also include buzzes and whistles, creating a diverse repertoire of sounds in communication or territorial displays. Their gazes may accompany their unique calls. Despite their unique blend of noises, their vocalizations generally have harsh, grating qualities.

Call

Audio by Jonathon Jongsma

/ CC BY-SA 3.0

Call

Audio by Paul Marvin

/ CC BY-NC-SA 4.0

Call

Audio by Jonathon Jongsma

/ CC BY-SA 3.0

There's more to learn about Common Grackle

View full details

Bronzed Cowbird

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Common Grackle

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

View full details

Common Grackle

Quiscalus quiscula

Also known as: Blackbird

General appearance

The common grackle is about the size of a crow, bearing a distinctive long tail with a crease down the middle. Coloring varies with two forms presented, namely, the 'Bronzed Grackle' and the 'Purple Grackle.' The former spots a bronzy body offset by a blue-black head while the latter shines with glosses of purple and green, offering less contrast.

Male vs female

Physical variations between the sexes are not explicitly stated. However, based on the Bronzed and Purple forms noted, it could be inferred that some slight difference in color intensity and gloss may exist.

Juvenile

Juvenile grackles present dark eyes in contrast to the whitish-yellow eye color observed in adults. Molting, a period prevalent in late summer, results in these younger birds having short or fragmented tails.

Size

11.0 - 13.4 in/2.6 - 5.0 oz

There's more to learn about Common Grackle

View full details

How to tell the Bronzed Cowbird from the Common Grackle

Visual differences

The Bronzed Cowbird (7.5-8.3 in, 1.9-2.5 oz) features a compact, glossy black or bronzed-brown plumage with striking red eyes and a robust bill. In contrast, the Common Grackle (11-13.4 in, 2.6-5 oz) is larger, with a long tail and sleek body. It exhibits two color forms: the Bronzed Grackle has a bronzy body with a blue-black head, while the Purple Grackle displays purple and green glosses. Grackles have distinctive whitish-yellow eyes as adults. Both birds have a significant tail difference: the Grackle’s is long and creased.

Key differences and behavior

The Bronzed Cowbird and Common Grackle both exhibit distinct behaviors that set them apart. Bronzed Cowbirds are brood parasites, laying eggs in at least 101 other species' nests, whereas Common Grackles form small colonies and construct their own nests. In courtship, Bronzed Cowbird males perform elaborate aerial displays, in contrast to grackle males, who fluff feathers and sing. Bronzed Cowbirds prefer open habitats like farmland and deserts, while Common Grackles favor tree-dense areas near water, such as farmland, suburbs, and marshes. Diet-wise, the cowbird leans towards seeds and insects, relying on snails for calcium, while the grackle's omnivorous diet includes insects, seeds, and even small animals. The grackle is more aggressive at feeders than the cowbird.

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