Cowbird vs Starling: What’s the Difference? (Explained)

Blackbirds come in various shapes and sizes, and two particular species that often capture our attention are the cowbird and the starling. While they may seem similar at first glance, these two bird species possess distinct features and characteristics that distinguish them from each other.

In this article, we’ll be taking a closer look at the physical, behavioral, and ecological differences between cowbirds and starlings to help you better understand and appreciate the diversity in the world of birds.

Although both cowbirds and starlings form part of the blackbird family, they exhibit unique attributes that set them apart from each other. Understanding these differences not only enriches our knowledge of avian diversity but also allows us to appreciate the intricacies of bird life in general.

Key Takeaways:

  • Cowbirds and starlings differ in their physical appearance, mainly in the shape of their beaks.
  • Cowbirds exhibit unique parasitic nesting behavior, while starlings are opportunistic in nesting and feeding.
  • Understanding these differences enriches our knowledge of avian diversity and bird life in general.

Cowbird vs Starling: Physical Differences

When observing cowbirds and starlings, you’ll notice some distinct physical differences that can help you identify each species.

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In terms of size, the European Starling is slightly larger than the Brown-headed Cowbird, with a length of about 7.5 to 9 inches and a weight ranging from 2.1 to 3.4 ounces. On the other hand, Brown-headed Cowbirds generally measure around 6.3 to 8.3 inches in length and weigh between 1.4 and 1.8 ounces.

Body Shape

As for the shape of these birds, you’ll find that cowbirds have a stocky body and a thick, conical bill, while starlings possess a more slender profile and a long, pointed bill. Furthermore, starlings have triangular wings, while cowbirds have more rounded wings.


The color pattern and iridescent feathers are also key aspects in differentiating the two species. European Starlings display glossy black plumage, which can appear iridescent with shades of green and purple under certain lighting conditions. In contrast, Brown-headed Cowbirds have a more muted coloration. Males exhibit a glossy black body with a brown head, while females exhibit a plain brown color overall.


Their wingspan can also serve as an identifier when distinguishing between cowbirds and starlings. European Starlings typically have a wingspan of 12.2 to 17.3 inches, while the Brown-headed Cowbird’s wingspan ranges from 11.8 to 15 inches.

To summarize, when identifying cowbirds and starlings, pay attention to their:

  • Size and weight: Starlings are generally larger and heavier.
  • Shape: Cowbirds have a stocky body and thick bill, while starlings have a slender body and pointed bill.
  • Color pattern: Starlings have glossy black plumage, while cowbirds have muted colors with males having a brown head and females being plain brown.
  • Wingspan: Starlings usually have a slightly larger wingspan than cowbirds.

By considering these physical characteristics, you’ll be better equipped to differentiate between these two unique bird species.

Unique Behavioral Differences

When observing cowbirds and starlings, you’ll notice some distinctive behaviors that set these two bird species apart. Cowbirds, specifically Brown-headed Cowbirds, are known for their unique approach to raising their young. Instead of building nests and taking care of their chicks, female cowbirds lay their eggs in the nests of other birds. This practice is known as brood parasitism. These eggs are then cared for by the unsuspecting foster parents, often at the expense of their own offspring [1].

In contrast, European Starlings, a common species of blackbirds that can be found in suburban areas, display highly social behavior. They usually form large flocks while in flight and often exhibit murmurations, which is an impressive aerial display of synchronized movement [2]. European Starlings have also been observed mimicking the calls of other birds, adding to their diverse vocal repertoire [3].

Another interesting aspect of cowbird behavior is the size of their juvenile offspring. Juvenile cowbirds can often grow to be larger than their foster parents, as they are about the size of a starling [4]. This size difference can cause host birds to expend even more energy caring for these larger chicks.

Unlike cowbirds, European Starlings engage in more direct competition with other birds, such as the Common Grackle, for nesting sites. Starlings have even been known to deter grackles from certain areas by exhibiting aggressive behavior or killing their young [5].

When it comes to bird identification, you’ll want to pay attention to specific physical and behavioral traits to determine whether you’re observing a cowbird or a starling. Considering factors such as size and shape, color pattern, nesting habits, flight behavior, and vocalizations will help you distinguish between these two fascinating bird species.

Habitat Differences

When it comes to the habitats of cowbirds and starlings, you will find that they have their preferences. Knowing these differences can help you understand their distribution and behavior.

Brown-headed Cowbirds are native to North America, commonly found in open habitats like fields, meadows, and grasslands. They often inhabit backyards, pastures, or open areas near woodland edges and are known to frequent areas where their preferred food sources, such as insects and seeds, are abundant. Cowbirds may also visit wetlands, such as marshes, due to the availability of insects and other food options.

On the other hand, European Starlings were introduced to North America by humans and have since adapted to various habitats across the continent. They thrive in open grasslands, meadows, and agricultural settings. Starlings are particularly common in urban and suburban areas where they can find an abundance of food from human activities. Though they don’t exclusively reside in wetlands, starlings can be spotted in marshy areas, especially during migration or while searching for food sources.

While both species favor open habitats, they differ in the types of regions they inhabit within North America. Cowbirds are native residents and can be found throughout most of the continent, with a significant presence in the northwest. In contrast, European Starlings were introduced and have expanded their range across most regions of North America.

In summary, while both Brown-headed Cowbirds and European Starlings occupy open habitats such as fields, meadows, and grasslands, they have differing preferences in terms of specific regions and environments. Cowbirds tend to stick to their native North American range while starlings can be found in various introduced habitats, including urban and suburban areas, wetlands, and marshes.

Diet and Feeding Differences

When comparing the diets of cowbirds and starlings, you’ll notice some key differences. Cowbirds primarily rely on insects for their food, such as grasshoppers, beetles, and caterpillars. Starlings, on the other hand, have a more versatile palate. They are omnivores, happily consuming seeds, nuts, berries, grains, and various invertebrates like spiders, larvae, worms, and caterpillars. This diversity in their diet allows starlings to thrive in different environments like grasslands and woodlands.

In addition to insects, cowbirds may also eat some seeds and grains. However, unlike starlings, they’re not frequent visitors to bird feeders. Starlings are known to be more attracted to bird feeders and can be spotted feasting on feed such as safflower seeds, whole peanuts, and suet.

When feeding on insects, both cowbirds and starlings prove to be beneficial for the ecosystems they inhabit. They help in controlling the populations of pests like beetles and caterpillars that feed on plants. However, it is essential to note that starlings may sometimes consume eggs and nestlings of other bird species, which can be detrimental to those populations.

In summary, the primary difference in the diets of cowbirds and starlings is their feeding preferences; cowbirds are more insectivorous, while starlings have an omnivorous diet that includes various seeds, grains, and invertebrates. Additionally, starlings are more likely to be observed at bird feeders compared to their cowbird counterparts. This information can help you better understand and appreciate the diets and feeding habits of these two fascinating bird species.

Nesting and Breeding Differences

When it comes to nesting and breeding, European Starlings and Brown-headed Cowbirds have noticeably different habits. Let’s examine their unique strategies for raising their young.

European Starlings are known for their communal approach to nesting. They form loose colonies and don’t establish or defend a proper territory, only protecting the immediate area around their nesting cavity. During the breeding season, the entire colony feeds within a shared home range 1. When selecting a nest site, they prefer pre-existing cavities like those found in trees or artificial structures. Starlings are also known for their aggressive tendencies; sometimes, they even remove the eggs and nestlings of other bird species from the targeted nest site.

On the other hand, Brown-headed Cowbirds have a completely different approach to raising their young. Instead of building nests, female cowbirds focus all their energy on producing eggs, sometimes laying more than three dozen a summer2. These eggs end up in the nests of other unsuspecting birds, making them foster parents to the cowbird chicks. The host bird nurtures and feeds the cowbird hatchlings, often at the expense of their own chicks. This unique strategy is known as brood parasitism3.

When female cowbirds lay their eggs in a host bird’s nest, they often remove some of the host eggs to make room. Incubation and fledging periods for cowbird eggs are relatively shorter than those of their hosts, giving cowbird nestlings a significant advantage in their race to survive. Some host birds, like the American Crow and Common Raven, recognize and reject cowbird eggs, while others remain unaware of the intruders.

This brood parasitic behavior has unfortunately led to a decline in the populations of some nesting birds, such as the Black-capped Vireo. To protect vulnerable species and their ecosystems, the Migratory Bird Treaty Act in the United States included provisions against the spread of Brown-headed Cowbirds4.

As you can see, European Starlings and Brown-headed Cowbirds have distinct differences in their nesting and breeding habits. Whether it’s the communal nesting of starlings or the cunning tactics of brood parasitic cowbirds, these bird species exhibit unique methods of ensuring the survival of their offspring.

Songs and Calls

When comparing the songs and calls of a Cowbird and a Starling, it’s essential to understand the distinct characteristics of these two bird species. Both Cowbird and Starling are considered songbirds, but they have different sound patterns and behaviors.

The Brown-headed Cowbird is known for its fascinating life history. Females lay their eggs in other birds’ nests, leaving the responsibility of raising their young to other species. In terms of their sounds, Cowbirds communicate through a variety of whistles, rattles, and warbling songs. These unique combinations allow Cowbirds to interact with other members of their species.

On the other hand, the European Starling produces a vocal repertoire of chattering, whistles, and even mimicry of other bird species’ sounds, such as the Northern Cardinal, Blue Jay, or the American Robin. This ability to imitate other birds makes it difficult to distinguish their sounds, and at times, challenging to identify them solely based on their calls.

In terms of appearance, both birds have a glossy black plumage. However, the European Starling often displays an iridescent green and purple sheen during specific seasons, easily identified with proper bird species maps.

Comparing these two birds by their sounds, you may encounter some similarities. Nevertheless, the Brown-headed Cowbird’s distinct whistles and rattles differ from the European Starling’s mimicry abilities and intricate chatters. If you are interested in identifying their sounds more accurately, you can utilize tools like Merlin Bird ID’s Sound ID to get real-time suggestions on bird songs and calls.

As you develop your birdwatching skills, grasping the difference between the songs and calls of Cowbirds and Starlings would be a valuable asset, helping you differentiate between these two common species. Keep an ear out for the vocalizations and migration patterns of these two birds, and you’ll enhance your understanding of their unique behaviors.

Frequently Asked Questions

What are the differences between cowbirds and starlings?

Cowbirds and starlings are two different types of birds. Cowbirds, specifically the Brown-headed Cowbird, belong to the family Icteridae and are found only in the Americas1. Starlings, on the other hand, are represented by the European Starling, which comes from the Sturnus family and can be found throughout Europe, Asia, and even North America2. These birds differ in appearance, behavior, and calls.

How can you distinguish between male and female starlings?

Male and female European Starlings have distinct characteristics that can help you identify their gender3. Adult male starlings have a darker, iridescent plumage, while females are lighter with more speckled feathers. During the breeding season, males have bright yellow beaks, while females have a duller, more pinkish beak.

Can cowbirds and starlings coexist?

Cowbirds and starlings can coexist in the same environment, although their interactions may vary. While both species are opportunistic, they have different nesting behaviors. Cowbirds are brood parasites, meaning they lay their eggs in other birds’ nests, relying on their host to raise their chicks4. Starlings, on the other hand, build their own nests and care for their offspring5. These varied behaviors suggest that cowbirds and starlings can live together but may not directly interact.

Are there any similarities between cowbirds and starlings?

Cowbirds and starlings share some similarities, such as being medium-sized, blackbirds with a somewhat similar shape. They are both opportunistic feeders, often seen foraging in open areas and eating a variety of food, including seeds, fruits, and insects. However, their differences in behavior, calls, and appearance outweigh these similarities.

What is the primary difference between the calls of cowbirds and starlings?

Cowbirds and starlings have distinct calls that can help you differentiate them. The Brown-headed Cowbird has a simple, liquid call that often sounds like a gurgling or bubbling noise6. In contrast, European Starlings are mimic birds, known for their complex vocalizations that include a mix of whistles, warbles, and imitations of other birds’ songs and calls7.

How can you tell a starling apart from a blackbird or grackle?

To tell a European Starling apart from a blackbird or grackle, pay attention to the bird’s size, plumage, and behavior8. Starlings have shorter tails and a more speckled appearance than blackbirds and grackles. Additionally, their vocalizations are different, with starlings mimicking a variety of calls, while blackbirds and grackles have unique, individual songs. Observing these traits can help you identify the species correctly.


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