Quick Answers
The main differences between rusty blackbirds and starlings are:
- Rusty blackbirds are medium-sized songbirds native to North America, while starlings are stocky songbirds native to Europe and Asia.
- Rusty blackbirds have a rust-colored head and breast in spring, while starlings are dark with light speckles year-round.
- Rusty blackbirds breed in wetlands and winter in the eastern US and Canada, while starlings are found year-round across North America.
- Rusty blackbird populations are declining, while starling populations are abundant to the point of being pests.
Rusty blackbirds and European starlings are both medium-sized black songbirds that can be found across much of North America. However, they belong to different families and have a number of distinguishing features when it comes to their appearance, behavior, habitat, and distribution. Rusty blackbirds are native to North America, while starlings were introduced from Europe and Asia. Understanding how to identify these two similar-looking species is important for birdwatchers and those involved in monitoring bird populations.
Appearance
Plumage
Perhaps the most noticeable difference between rusty blackbirds and starlings is their plumage. Rusty blackbirds get their name from the distinctive rusty color on their heads and breasts that is prominent during the spring breeding season. Their backs and wings look black from a distance but are actually speckled with white when viewed up close. Outside of spring, they lack the rusty coloration and appear mostly black.
Starlings, in contrast, are dark colored with light speckling year-round. The speckles can be white, buff, or iridescent. Their bills also tend to be longer and thinner compared to the shorter bill of a rusty blackbird. While starlings are short-necked and stocky, rusty blackbirds have a longer neck and more slender build.
Molting
In addition to differences in color, the molting patterns of rusty blackbirds and starlings differ. Rusty blackbirds have a complex molt cycle where they molt and change feathers multiple times per year. This includes a complete molt after breeding in summer when they lose all their feathers and grow a new set.
Starlings, on the other hand, only molt once a year after breeding. Their molt is incomplete, meaning they do it gradually and hold onto some old feathers as new ones grow in. This molt results in their fresh, speckled appearance. Understanding when these species molt can be another way to help tell them apart.
Gender Differences
Males and females of both species also show some subtle differences in appearance. Male rusty blackbirds tend to be larger than females and have brighter rusty coloring during the breeding season. Females are more uniformly dark gray-brown.
Male starlings generally have more iridescent feathers and larger white speckling compared to females. But overall, male and female starlings look quite similar. Paying attention to subtle size and color differences can aid in identifying gender.
Juveniles
Juvenile birds in their first year of life can also look different than adults. Juvenile rusty blackbirds have brownish plumage overall and lack rusty coloring until their first breeding season. Juvenile starlings strongly resemble adult females but are paler overall and have less distinct speckling. Familiarity with juvenile appearances is helpful, as young birds increase in number during the summer months.
Size
Rusty blackbirds and starlings occupy a similar size range, making size alone an unreliable way to tell them apart. Rusty blackbirds measure 16.5-9.4 inches (42-24 cm) from bill to tail tip with a wingspan of 25.6 inches (65 cm). Starlings measure 7.9-9.1 inches (20-23 cm) long with a 16.5 inch (42 cm) wingspan.
So while starlings are on the stockier end of that size range, there is considerable overlap. Taking into account other factors like plumage and proportions in addition to size gives a more complete picture when identifying between these mid-sized black birds. Rusty blackbirds are longer-bodied and -necked while starlings are more compact and bull-headed in profile.
Voice
Both rusty blackbirds and starlings are vocally talented songbirds. However, their vocalizations differ and add another layer in distinguishing between them.
Rusty Blackbird Sounds
The song of the rusty blackbird is a series of squeaky, ringing notes that some describe as sounding like a rusty gate hinge. They make other calls described as “liquid bubbling” as well as croaks and squeaks. During winter and migration they can be quite vocal.
Starling Sounds
Starlings produce a wide variety of sounds from melodious whistles mimicking other birds to harsh rattles and squawks. Their jumbled warbling songs incorporate mimicked sounds from their environment like car alarms and squeaky gates. Their large repertoire includes metallic chirps, whistles, clicks, and clucks.
Differences
While both species sing and are capable mimics, the rusty blackbird’s sounds are generally more metallic-sounding and limited in variety compared to the starling’s diverse mix of tuneful and harsh vocalizations. Listening to audio recordings and learning their distinct voices can help birdwatchers recognize these species in the field.
Behavior
Rusty blackbirds and starlings differ in many aspects of their behavior, from migration patterns to social systems to feeding techniques. Understanding these behavioral differences provides more clues on how to tell them apart.
Migration
Rusty blackbirds are migratory, breeding during the summer in Canada and the northern US before migrating south to overwinter in the southern US. Starlings are partially migratory, with northern populations migrating south but other populations remaining year-round residents across North America.
This means rusty blackbirds will be absent from much of their breeding range during the winter months while starlings can be found year-round across most of the continent. Paying attention to timing and location can help distinguish between these species that occupy the same areas seasonally.
Social Behavior
Rusty blackbirds lead predominantly solitary lives, coming together only for breeding purposes or while migrating and wintering. Starlings, on the other hand, are extremely social birds year-round, gathering in large flocks numbering into the thousands.
Seeing a lone blackbird or a pair likely means it’s a rusty blackbird, while a larger flock increases the odds of it being starlings. However, flocking behavior alone isn’t definitive, as both species can form groups during migration.
Feeding
The feeding habits of rusty blackbirds differ from starlings as well. Rusty blackbirds use their long bills to forage on the ground, picking insects and other prey from damp soil. Starlings are less specialized foragers, gathering food from many places like lawns or feeders.
Watching a blackbird probe into muddy ground indicates a rusty blackbird, while seeing one perched at a feeder or hovering over grass is more typical of starlings. The two might occasionally share the same food source, but their foraging tactics and preferences differ.
Interactions with Other Species
Given their more solitary nature, rusty blackbirds are not usually aggressive competitors at bird feeders. Starlings, however, are notoriously bold and aggressive birds. They readily displace other species from feeders and nest cavities.
So if blackbirds are seen bickering with chickadees, woodpeckers, or other feeder birds, chances are they are starlings and not the more mellow rusty blackbird. Assessing how they interact with other species can provide identification insights.
Habitat
Preferred breeding and wintering habitats offer additional clues in distinguishing rusty blackbirds from starlings based on location.
Breeding Habitat
Rusty blackbirds nest in wetland habitats, especially bogs, fens, swamps, and wet woods across Canada and Alaska as well as northern parts of the Great Lakes, New England, and Pacific Northwest regions. They are most likely to be found in these forested wetland areas during the summer breeding season.
Starlings are generalists when it comes to nesting and can breed in a wide variety of habitats from farmlands to city centers. But they most commonly nest in cavities in trees or human structures like bridges, buildings, and nest boxes.
Winter Habitat
On their wintering grounds in the southeastern United States, rusty blackbirds use wooded swamps and floodplain forests often associating with tree species like bald cypress, tupelo, and sweetgum.
Starlings use an even broader array of habitats in winter from suburbs and farms to open woodlands. Central and western populations of starlings may migrate south in winter, sometimes overlapping with rusty blackbird habitat.
Migration Stopover Habitat
During migration, both species stopover in areas that provide plentiful food sources. Rusty blackbirds look for wooded wetlands and floodplains between their breeding and wintering grounds. Starlings use a greater variety of habitats with abundant fruits and seeds or ample insect prey.
Monitoring locations and habitat types visited by blackbirds during spring or fall migration can help determine their identity. Understanding these habitat preferences expands the toolbox for distinguishing these species.
Range and Distribution
Where these species occur across North America also differs, providing helpful clues on identification.
Rusty Blackbird Range
Rusty blackbirds breed across Canada and Alaska as well as parts of the northeastern and northwestern United States. They migrate through the eastern half of the U.S. to winter primarily along the Atlantic Coast and Gulf of Mexico. Their populations have declined substantially in recent decades.
Starling Range
Starlings were introduced to North America in the late 1800s and now occupy a range that spans Alaska and Canada south throughout the contiguous U.S., Mexico, and Central America. They are found year-round across most of this range. Huge flocks congregate in western and southern areas during winter.
Overlap
There is broad overlap between rusty blackbird and starling ranges in the United States and southern Canada. During summer, rusty blackbirds occur farther north while starlings are widespread. Winter range maps show the opposite, with rusty blackbirds concentrated along the Atlantic and Gulf coasts while starlings occupy most of the remaining areas.
Checking location and season against range maps provides helpful context in puzzling out a blackbird’s identity. With starlings being common and widespread, an unfamiliar blackbird is more likely to be a rusty blackbird anywhere within its more limited range.
Population Trends
The modern trajectories of rusty blackbird and starling populations also differ markedly:
Rusty Blackbird Declines
Over the past 50 years, rusty blackbird numbers have declined steeply across their range by an estimated 85-95 percent. Habitat loss on both their breeding and wintering grounds along with mercury contamination are thought to be major factors. They are now considered a species of high conservation concern.
Starling Increases
Meanwhile, starling numbers grew exponentially after their introduction to North America. Though populations have declined somewhat in recent decades, they remain abundant to the point of being considered pests in many areas. Huge roosts numbering hundreds of thousands or even millions of birds may gather in winter.
Implications
Given the growing rarity of rusty blackbirds, an out-of-place looking blackbird is now statistically more likely to be that species than the widespread and abundant starling. Understanding these opposite population trends can inform the likelihood of a sighting being one species or the other. Documenting occurrences of rusty blackbirds is valuable data for researchers monitoring this species of conservation concern.
Summary Comparison
Trait | Rusty Blackbird | Starling |
---|---|---|
Plumage | Rusty head and breast in spring, otherwise gray-brown speckled with white | Dark overall with white or iridescent speckling year-round |
Molt | Complete molt occurs twice per year | One incomplete molt per year |
Size | 16.5-9.4 in long with 25.6 in wingspan | 7.9-9.1 in long with 16.5 in wingspan |
Shape | Slender, long-necked | Stocky, short-necked |
Voice | Metallic squeaks, rusty gate-like song | Varied mimicking and rattling sounds |
Sociality | Solitary, pairs, or loose flocks | Gregarious flocks |
Foraging | Probes soil | Variable by location |
Aggression | Docile at feeders | Aggressive at feeders |
Breeding habitat | Northern wetlands | Trees, cavities, structures |
Winter habitat | Southern swamps and floodplains | Varied open and settled areas |
Range | Across northern North America | Throughout North America |
Population trend | Declining steeply | Abundant to overabundant |
Conclusion
Despite some similarities, rusty blackbirds and European starlings differ significantly in appearance, voice, behavior, preferred habitat, distribution, and population status. Key traits to note include rusty blackbird’s rust-colored breeding plumage, wetland habitats, solitary behavior, and declining numbers versus the starling’s year-round dark speckled appearance, vocal mimicry, aggression around feeders, urban adaptability, and abundant populations. Location and season also provide helpful context clues to ID between these two similar blackbird species found across much of North America. Understanding their differences aids birdwatchers and biologists in distinguishing between them.