Brown-Headed Cowbird vs Common Grackle

Brown-Headed Cowbird

Molothrus ater

How to recognise a brown-headed cowbird?

General appearance

The brown-headed cowbird is a medium-sized bird, approximately the size of a robin or sparrow, measuring between 6-8 inches or 15-20 cm. Its wing shape is broad and the tail is either rounded or square-tipped. The bird's coloration includes hues of black, brown, green, and tan.

Male vs female

In terms of gender differences, male brown-headed cowbirds are glossy black and sport a contrasting brown head. On the other hand, females have a different appearance, with a plain dusty brown color and a darker sparrowlike bill.

Juvenile

Juvenile brown-headed cowbirds have a unique appearance that changes as they mature. Initially, they are streaked and tend to resemble female adults but their coloration grows darker as they age. Further observation is needed to note if this pattern is consistent across all seasons.

Size

6.3 - 7.9 in/1.1 - 1.8 oz

Habitat

Primary habitat

The brown-headed cowbird favors open or semi-open countrysides like farms, fields, prairies, and wood edges, concentrating in farmlands or pastures during winter for easy foraging.

Additional range

In the breeding season, it is more widespread, occupying grasslands, brushy regions, forest edges, and even deserts, yet it avoids dense unbroken forests.

Range Map

What do brown-headed cowbirds like to eat?

Natural diet

The brown-headed cowbird's diet primarily consists of seeds and insects. During summer, their diet is about half seeds and for more than 90% in winter. The seeds include those from grasses, weeds, and waste grain. The remainder of their diet is largely insects, particularly grasshoppers, beetles, and caterpillars, along with spiders and millipedes.

Bird feeders

At bird feeders, brown-headed cowbirds typically consume seeds. They may eat a variety of birdseed mixes, such as sunflower seeds, millet, and cracked corn, which are commonly available in feeders.

What does a brown-headed cowbird sound like?

The brown-headed cowbird's vocalizations are highly varied, encompassing sounds described as a squeaky gurgle, a check or rattle-like call, and a chatter, chirp, or whistle. These vocal expressions can follow a falling, flat, or rising pattern. The cowbird's call types can range from a simple "hi", to a more complex trill, all contributing to its unique bird song.

Call

Audio by Jonathon Jongsma

/ CC BY-SA 3.0

Call

Audio by Dkazdan

/ CC BY-SA 3.0

Song

Audio by Jonathon Jongsma

/ CC BY-SA 4.0

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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

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Brown-Headed Cowbird

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Common Grackle

Brown-Headed Cowbird

Molothrus ater

General appearance

The brown-headed cowbird is a medium-sized bird, approximately the size of a robin or sparrow, measuring between 6-8 inches or 15-20 cm. Its wing shape is broad and the tail is either rounded or square-tipped. The bird's coloration includes hues of black, brown, green, and tan.

Male vs female

In terms of gender differences, male brown-headed cowbirds are glossy black and sport a contrasting brown head. On the other hand, females have a different appearance, with a plain dusty brown color and a darker sparrowlike bill.

Juvenile

Juvenile brown-headed cowbirds have a unique appearance that changes as they mature. Initially, they are streaked and tend to resemble female adults but their coloration grows darker as they age. Further observation is needed to note if this pattern is consistent across all seasons.

Size

6.3 - 7.9 in/1.1 - 1.8 oz

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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

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How to tell the Brown-Headed Cowbird from the Common Grackle

Visual differences

The Brown-Headed Cowbird measures 6-8 inches with a weight of 1.1-1.8 oz. Males are glossy black with a contrasting brown head, while females are a plain dusty brown. The Common Grackle is larger, at 11-13 inches and 2.6-5 oz, with a long tail. It displays bronzy or purplish-green iridescence. Both sexes are similar, with adults having striking whitish-yellow eyes. Cowbirds have a broader wing shape, while grackles feature a notable long tail with a crease. Cowbirds differ with a round tail, while grackles have a fan-like tail.

Key differences and behavior

Brown-headed cowbirds and common grackles exhibit distinct behaviors and ecological preferences. Cowbirds follow livestock to feed on insects and seeds, rarely engaging in parental duties as they are brood parasites, laying eggs in other birds' nests. In contrast, grackles are omnivorous, eating a broad range of items from insects to small vertebrates. They often steal food and engage in "anting" for pest control. Cowbirds prefer open farmlands and avoid dense forests, whereas grackles are found in varied open landscapes, including suburban areas, often nesting in colonies. During courtship, both species use display behaviors to attract mates, but cowbirds rely on hosts for chick-rearing, while grackles build concealed nests and share parental duties. Cowbirds focus on seeds in winter, while grackles' diet diversifies widely. Grackles are aggressive at feeders; cowbirds are less so. Overall, cowbirds are opportunistic parasites, whereas grackles are adaptable omnivores.