Steller’s Jays are large songbirds with large heads, chunky bodies, rounded wings, and a long, full tail. The bill is long, straight, and powerful, with a slight hook. Steller’s Jays have a prominent triangular crest that often stands nearly erect from their head. At a distance, Steller’s Jays are very dark jays, lacking the white underparts of most other jays. The head is charcoal black and the body is all blue (the blue lightest, almost sparkling, on the wings). The white markings above the eye are fairly inconspicuous.
Steller's Jays are about the same size as a Western Scrub-Jay. They have a length of 11.8-13.4 inches (30-34 centimeters) and weigh 3.5-4.9 ounces (100-140 grams). They have a wingspan of 17.3 inches (44 centimeters).
Regional DiffrencesScientists have described 16 subspecies of the Steller’s Jay in North and Central America, showing varying combinations of black and blue on the crest, head, and body. The Queen Charlotte Islands off British Columbia are home to the largest and darkest subspecie. In mainland North America, notice the differences between darker Pacific forms, with blue streaks over the eye, and lighter Rocky Mountain forms with white streaks and a partial white eyering.
Steller's Jays are inabitants of the mountainous West of North America. They are residents, though breeding populations breeding in high elevations may move to lower elevations in winter. Steller’s Jays are birds of coniferous and coniferous-deciduous forests. In the southwestern U.S. and Mexico they also live in arid pine-oak woodland. They are typically found at elevations of 3,000-10,000 feet, and lower in the evergreen forests of the Pacific coastal foothills. During irruptive movements in some winters, flocks may move through unusual habitats such as the Sonoran desert.
A generalist forager, Steller’s Jays eat insects, seeds, berries, nuts, small animals, eggs, and nestlings. Around people, they also eat garbage, unguarded picnic items, and food from bird feeders. With large nuts such as acorns and pinyon pine seeds, Steller’s Jays carry several at a time in their mouth and throat, then bury them one by one as a winter food store. Steller’s Jays are opportunists and will steal food from other birds or look for handouts from people.
Both members of the pair choose the nest site, typically in a conifer, and gather nest material together. Steller’s Jays put their nests on horizontal branches close to the trunk and often near the top of the tree (though some nests are built much lower, even just above ground level). The nest is a bulky cup of stems, leaves, moss, and sticks held together with mud. The inside is lined with pine needles, soft rootlets or animal hair. The finished nest can be 10-17 inches in diameter, 6-7 inches tall, and 2.5-3.5 inches deep on the inside.
Steller's Jays have one brood per year with 2-6 eggs in each. The eggs are bluish-green, spotted with dark brown, purplish, or olive. They have a length of 1.1-1.4 inches (2.7-3.5 centimeters) and a width of 0.8-0.9 inches (2-2.4 centimeters). Incubation period is 16 days and nesting period is 16 days.
Steller’s Jays move around with bold hops of their long legs, both on the ground and among the main branches of conifers. They pause often to eye their surroundings, cocking their head with sudden movements this way and that.
Jays have incredible spatial memories, so Steller’s Jays can remember where they've stored surplus food in caches. They also raid the caches of Clark’s Nutcrackers and other jays. Steller’s Jays are common nest predators, stealing both eggs and chicks from the nests of many species.
They are very social, traveling in groups, sometimes playing with or chasing each other, or joining mixed-species flocks.
One of the most vocal species of mountainous forests, Steller’s Jays keep up a running commentary on events and often instigate mobbing of predators and other possibly dangerous intruders.
Males and sometimes females sing a quiet series of whistled, gurgled, and, popping sounds that they string together. This song is most frequently heard during courtship. Steller's Jays also give a loud and repeated shook shook shook shook call year-round, in flight, while perched, and during aggressive interactions. They also make a variety of guttural sounds and a harsh, nasal sounding growl. Sometimes they mimics birds, mammals, and other sounds in their environment.
Steller's Jay populations remained relatively stable, showing some local declines recently.
- Steller's and Blue Jays are the only North American jays with crests. The Blue Jay is expanding its range westward. Where they meet, the two species occasionally interbreed and produce hybrids.
- Steller’s Jays have the dubious honor of being one of the most frequently misspelled names in all of bird watching. Up close, the bird’s dazzling mix of azure and blue is certainly stellar, but that’s not how you spell their name. Steller’s Jays were discovered on an Alaskan island in 1741 by Georg Steller, a naturalist on a Russian explorer’s ship. When a scientist officially described the species, in 1788, they named it after him.
- The Steller's Jay and the Blue Jay are the only New World jays that use mud to build their nests.
- They’ve occasionally been seen attacking and killing small adult birds.
- An excellent mimic with a large repertoire, the Steller’s Jay can imitate birds, squirrels, cats, dogs, chickens, and some mechanical objects.
- The oldest recorded Steller’s Jay was a male, and at least 16 years and 1 month old when he was found in Alaska in 1987. He had been banded in the same state in 1972.
- Steller's Jays are also called Chara de Steller (in Spanish) and Geai de Steller (in French).