Blue jays and Steller’s jays are two species of jays found in North America. Both are intelligent, vocal birds in the Corvidae family, which includes crows, ravens, and magpies. However, there are some key differences between these two jay species when it comes to their appearance, habitat, behavior, diet, and more.
Appearance
The most noticeable difference between blue jays and Steller’s jays is their plumage. Blue jays have bright blue upperparts, a white underside, and black markings on their wings and tail. The blue color comes from light refracting through their feathers. Male and female blue jays have identical plumage.
Steller’s jays, on the other hand, have deep blue upperparts and a black head. Their underside ranges from gray to dark blue. They also have a crest on top of their head made of elongated feathers. Compared to blue jays, Steller’s jays have longer tails and beaks as well. There is no sexual dimorphism in plumage between male and female Steller’s jays.
Blue Jay
Here are some key facts about the appearance of blue jays:
- Bright blue upperparts
- White underside
- Black markings on wings and tail
- No differences in plumage between males and females
Steller’s Jay
Key facts about Steller’s jays:
- Deep blue upperparts
- Black head
- Gray to dark blue underside
- Crest on top of head
- Longer tails and beaks than blue jays
- No differences in plumage between males and females
Habitat
Blue jays and Steller’s jays also differ in their preferred habitats.
Blue jays are found in forests across much of eastern and central North America. They thrive in both deciduous and coniferous forests, especially near oak trees. Blue jays are also commonly found in residential areas with trees and thick vegetation.
Steller’s jays, on the other hand, are found along the Pacific Coast, as well as parts of the Rocky Mountains and southwest Canada. They prefer coniferous forests made up of pine, spruce, fir, and cedar trees. Steller’s jays are common in mountain forests up to 10,000 feet in elevation.
Blue Jay
- Found in forests of eastern and central North America
- Prefer deciduous and coniferous forests
- Often found near oak trees
- Also found in residential areas with trees
Steller’s Jay
- Found along the Pacific Coast and parts of the Rockies
- Prefer coniferous forests with pine, spruce, fir, cedar
- Common in mountain forests up to 10,000 ft elevation
Behavior
Blue jays and Steller’s jays exhibit some behavioral differences as well.
Blue jays are known for their intelligence. They are highly curious and often playful. Blue jays mimic hawks as a way to scare off other birds from food sources. They are also vocal birds with a wide range of calls. Due to their bold nature, blue jays may bully or take advantage of smaller birds.
Steller’s jays are also intelligent and vocal. However, they are generally less aggressive than blue jays toward other birds. Steller’s jays are highly social and form lifelong pairs with their mates. They communicate using many different vocalizations and seem to have a cooperative relationship with other Steller’s jays.
Blue Jay
- Intelligent and curious
- Often playful
- Mimic hawks to scare off other birds
- Wide range of vocalizations
- Can be aggressive toward smaller birds
Steller’s Jay
- Intelligent and vocal
- Less aggressive than blue jays
- Highly social
- Form lifelong pairs
- Cooperative with other Steller’s jays
Diet
The diets of blue jays and Steller’s jays differ somewhat based on the habitats they live in.
Blue jays are omnivorous, eating a wide variety of foods. Their diet consists of seeds, nuts, fruits, berries, arthropods, eggs, small vertebrates, and even carrion. They sometimes raid nests for eggs and nestlings. Blue jays often cache food like acorns to eat later. They prefer to forage in trees but also forage on the ground.
Steller’s jays are also omnivorous, feeding on fruits, nuts, seeds, eggs, and small animals. However, they rely more heavily on pine nuts and other conifer seeds compared to blue jays. Steller’s jays are expert at extracting seeds from cones. They frequently store food in caches throughout their territory.
Blue Jay
- Omnivorous
- Eats seeds, nuts, fruits, berries, arthropods, eggs, small vertebrates, carrion
- Sometimes raids nests
- Often caches food like acorns
- Prefers to forage in trees
Steller’s Jay
- Also omnivorous
- Feeds on fruits, nuts, seeds, eggs, small animals
- Relies more on pine nuts and conifer seeds
- Expert at extracting seeds from cones
- Frequently caches food
Nesting
When it comes to nesting habits and reproduction, there are some notable differences between these jay species.
Blue jays build nests 10-25 feet above ground in the branches of deciduous trees. Nests are constructed from twigs, bark, roots, and sometimes mud. Inside is lined with soft materials like grass and pine needles. Females lay between 3-6 eggs that incubate for 16-18 days. Both parents feed the young, which fledge from the nest at around 17-21 days old.
Steller’s jays nest higher up than blue jays, typically 20-60 feet above ground. They build large bowl-shaped nests out of twigs, bark, moss, roots, and other materials. The inside of the nest is lined with soft bark, grass, and hair. Females lay 2-5 eggs that incubate for 16 days. The young fledge from the nest after 18-22 days.
Blue Jay
- Nest 10-25 ft above ground
- Nest in branches of deciduous trees
- Build nests from twigs, bark, roots, mud
- Line nest with grass, pine needles
- Lay 3-6 eggs
- Eggs incubate for 16-18 days
- Young fledge at 17-21 days old
Steller’s Jay
- Nest higher up, 20-60 ft above ground
- Build large bowl-shaped nests
- Use twigs, bark, moss, roots for nests
- Line nest with bark, grass, hair
- Lay 2-5 eggs
- Eggs incubate for 16 days
- Young fledge after 18-22 days
Range and Population
Blue jays and Steller’s jays have overlapping but distinct ranges in North America. Their total populations differ considerably as well.
Blue jays are found throughout the eastern and central United States, as well as parts of southern Canada. Their total population is estimated at between 22 and 28 million birds. Their numbers increased during the 20th century as forests regrew and suburban areas expanded.
Steller’s jays have a much smaller range confined to the Pacific Coast region, including western British Columbia down to northern California. Occasional vagrants can be found further inland. The global population of Steller’s jays is estimated at just 3.5 million birds.
Blue Jay
- Range throughout eastern and central US, southern Canada
- Population estimated at 22-28 million
- Increased in 20th century
Steller’s Jay
- Range confined to Pacific Coast
- Global population around 3.5 million
- Occasional vagrants inland
Taxonomy
Blue jays and Steller’s jays are classified into different scientific genera.
The blue jay’s scientific name is Cyanocitta cristata. It is the only species within the Cyanocitta genus. Fossil evidence indicates Cyanocitta jays originated in North America around 23 million years ago.
Steller’s jay is classified as Cyanocorax stelleri. It is one of several closely related jay species within the Cyanocorax genus found throughout North and Central America. Fossils of early Cyanocorax jays date back over 5 million years.
Blue Jay
- Scientific name: Cyanocitta cristata
- Only species in Cyanocitta genus
- Originated in North America ~23 million years ago
Steller’s Jay
- Scientific name: Cyanocorax stelleri
- One of several Cyanocorax jays
- Genus originated over 5 million years ago
Conservation Status
Neither blue jays or Steller’s jays are considered threatened or endangered currently. However, Steller’s jays have a higher conservation priority.
Blue jays are classified as a species of Least Concern by the IUCN. Their large range and stable population trends mean they are not currently vulnerable. No major threats to the overall blue jay population are known.
Steller’s jays are also Least Concern but have a much smaller global population confined to the narrow Pacific Coast region. Loss of mature coniferous habitat is a potential threat. Climate change may also impact their high-elevation mountain habitat over the long term.
Blue Jay
- Classified as Least Concern
- Large range and stable population
- No major threats known
Steller’s Jay
- Also Least Concern currently
- Smaller population only in Pacific Coast
- Loss of coniferous habitat a potential threat
- Climate change impacts possible
Conclusion
In summary, while blue jays and Steller’s jays are closely related corvid species, they can be distinguished by differences in appearance, habitat preferences, behavior, diet, nesting habits, range, taxonomy, and conservation status. Blue jays are more widespread, bold, and aggressive, while Steller’s jays have more specialized habitat needs and smaller total numbers. Both are highly intelligent, vocal birds playing important ecological roles across North America.