Blue jay
The blue jay, Cyanocitta cristata, produced a surprise in 2023. Near San Antonio, Texas, a hybrid of a male blue jay and a female green jay was found and photographed. The green jay is Cyanocorax luxuosus. The offspring was given the portmanteau name grue jay, and its hybrid status was confirmed in 2025.
The blue jay itself is a passerine bird of the family Corvidae, native to eastern North America. It is common in residential areas, so most people who live within its range have seen one. Yet the bird keeps a surprising number of puzzles.
How can a feather lose its blue when it is crushed? Why would a bird that screams at hawks also imitate them? Why do some jays fly south one winter and stay home the next, with no one able to say for certain why? And how did one species end up as a provincial emblem, a university mascot, a folktale hero and the symbol of a Major League Baseball team?
Crush a blue jay feather and its blue disappears. That small experiment reveals how the bird gets its color. The blue is not a pigment. It results from light interference caused by the internal structure of each feather, and crushing destroys that structure. The actual pigment in the feathers is melanin. Scientists call the effect structural coloration.
A blue jay measures 22 to 30 cm from bill to tail and weighs 70 to 100 g. Its wingspan runs from 34 to 43 cm. Weight follows climate. Jays from Connecticut averaged 92.4 g, while jays from warmer southern Florida averaged 73.7 g, a pattern consistent with Bergmann's rule.
The crest on the head works like a mood display. When a jay is excited or aggressive, the crest rises fully. A frightened bird makes it bristle outward, brushlike. A jay feeding among other jays, or simply resting, keeps the crest flattened against its head.
The plumage runs from lavender-blue to mid-blue across the crest, back, wings and tail. The face is white and the underside is off-white. A black collar circles the neck and extends to the sides of the head. The wing primaries and tail are strongly barred with black, sky-blue and white. The bill, legs and eyes are all black. Males and females look almost identical, though the male is slightly larger, and the plumage does not change through the year.
The black on the nape, face and throat varies a great deal from one bird to the next, and it is believed to help individual jays recognize one another.
Mark Catesby, an English naturalist, published the first description of the blue jay in 1731 in his Natural History of Carolina, Florida, and the Bahamas. He called it Pica glandaria cærulea cristata. In 1758, Carl Linnaeus described it again as Corvus cristatus in his edition of Systema Naturae.
The French ornithologist Charles Lucien Bonaparte renamed it Cyanocorax cristatus in 1838. He did so in A geographical and comparative list of the birds of Europe and North America. Hugh Edwin Strickland gave it the modern scientific name, Cyanocitta cristata, in 1845.
The roots of that name are descriptive. Cyanocitta joins the Greek kyaneos, meaning blue, with kitta and kissa, words for a chattering bird or jay. The phrase "blue chatterer" points to the bright blue of the head, nape, back and tail. The species name cristata means crested or tufted, and refers to the prominent blue crest.
The English word jay comes from the bird's noisy, garrulous nature. It has been applied to many other birds in the same family, most of them also gregarious. Jays are also called jaybirds.
Four subspecies are generally accepted, but the variation is subtle and shifts gradually across the map. No firm boundaries can be drawn between the inland forms, while the coastal races are easier to delimit.
The northern blue jay, Cyanocitta cristata bromia, is the largest. Its plumage is fairly dull and its blue is rather pale. It lives in Canada and the northern United States, and its type locality is Wooster, Wayne County, Ohio.
The coastal blue jay, Cyanocitta cristata cristata, is the nominate subspecies. It is mid-sized and vivid blue. It lives along the coast from North Carolina to Texas, except southern Florida, and its type locality is in southeastern South Carolina.
The interior blue jay, Cyanocitta cristata cyanotephra, is also mid-sized. Its mantle is quite dark blue and contrasts cleanly with a very white underside, a broader white wingbar and a white tail tip. It lives inland from southeastern Wyoming and Nebraska to west Kansas, Oklahoma and northern Texas. Its type locality is Kenton, Cimarron County, Oklahoma.
The smallest of the four is the Florida blue jay, Cyanocitta cristata semplei. It lives in southern Florida and was described from Coconut Grove, Miami-Dade County, with color much like the northern bird's.
The eastern foothills of the Rocky Mountains mark the blue jay's usual western edge. The species occurs from southern Canada through the eastern and central United States, south to Florida and northeastern Texas. Farther west begins the arid pine forest and scrub of the closely related Steller's jay, Cyanocitta stelleri.
That boundary has been softening. The blue jay is now a rare but regularly seen winter visitor along the northern US and southern Canadian Pacific Coast. Because its range now overlaps with that of the Steller's jay, the two species may sometimes hybridize.
Trees help explain the westward push. Over the past century, fire suppression and tree planting increased the number of trees across the Great Plains. That change helped the blue jay expand, along with many other bird species.
Population counts from 1966 to 2015 tell two different stories. Along the Atlantic coast, blue jays declined. Across the northern part of the range, including Labrador, Nova Scotia, southern Quebec and southern Manitoba, they grew by more than 1.5% a year.
Habitats range from the pine woods of Florida to the spruce-fir forests of northern Ontario. The blue jay is less abundant in denser forests and prefers mixed woodlands with oaks and beeches. It has adapted well to human activity and turns up in parks and residential areas. It can even cope with wholesale deforestation, provided human activity gives it other ways to get by.
The northernmost subspecies, bromia, migrates when conditions demand it. In the far north it may withdraw several hundred kilometers south. Thousands of blue jays have been seen moving in flocks along the Great Lakes and Atlantic coasts. They travel by day, in loose flocks of 5 to 250 birds.
Much about this behavior remains a mystery. Some jays stay through the winter in every part of the range. Young birds may be more likely to migrate than adults, but many adults go too. Some individuals fly south one year, stay north the next winter, and then fly south again.
No one has concretely worked out why they migrate when they do. Weather and the abundance of winter food are the likely factors, and those same conditions can decide whether other northern birds move south.
Most people know the blue jay by its alarm call, a loud, almost gull-like scream. Individual jays vary perceptibly in their calling style. A second call is a high-pitched jayer-jayer that speeds up as the bird becomes more agitated. It can be confused with the chickadee's song, which opens with a slow chick-ah-dee-ee.
Blue jays use these calls to band together and mob predators such as hawks, driving them away from the nests. If an owl roosts near a nest during the day, the jays mob it until it takes a new roost. Smaller birds often recognize the alarm when a hawk or other danger is near, and they hide.
Mimicry adds another layer. A blue jay may copy the calls of red-tailed and red-shouldered hawks so well that it is sometimes hard to tell which bird is calling. The reason is uncertain. The jay may be testing whether a hawk is nearby, or it may be scaring off birds that compete for food. Like other corvids, it may also learn to mimic human speech.
Quieter calls serve jays at close range. The most distinctive is known as the "rusty pump", named for its squeaky resemblance to an old hand-operated water pump.
A speed of roughly 32 to 40 kph is the blue jay's unhurried pace when nothing provokes it. It flies with body and tail held level and with slow wing beats. That slowness makes it easy prey for hawks and owls in open areas. Virtually all raptors that share its range may take it, especially swift bird-hunting specialists such as the Accipiter hawks.
Eggs and young, up to the fledgling stage, face many predators. These include tree squirrels, snakes, cats, crows, raccoons, opossums, other jays and possibly many of the same birds of prey that attack adults.
The jay's own reputation for violence is mixed. Blue jays are very territorial and will chase other birds from a feeder for an easier meal. They sometimes raid nests, stealing eggs, chicks and even nests. Some have been found to have decapitated other birds. They have also attacked or killed smaller birds and foliage-roosting bats such as Eastern red bats. A jay may be aggressive toward a human who comes close to its nest.
The nest-raiding image may be exaggerated. In one study, only 1% of the food matter was bird material. Even so, other passerines may still mob jays that enter their breeding territories.
Bottle caps and pieces of aluminum foil attract young blue jays. They playfully snatch brightly colored or reflective objects and carry them around until they lose interest. Like other corvids, blue jays are highly curious and considered intelligent.
Tool use is confirmed both in captivity and in the wild. Captive jays have used strips of newspaper to obtain food, and captive fledglings have tried to open the doors of their cages. In the wild, one jay was observed using a piece of bark to help catch a spider.
The Audubon Society estimates that 75% of a blue jay's diet is vegetable matter, even though the bird is omnivorous. Its strong black bills crack nuts, usually while the bird holds them with its feet, and also handle corn, grains and seeds. Peanuts in the shell are a particular favorite.
The menu also includes acorns, beech mast, weed seeds, fruit, berries, bread, meat, small invertebrates of many types, scraps in town parks and bird-table food. Eggs and nestlings are eaten only rarely. Some jays cache food, although how much differs widely between individuals.
For all their swagger, blue jays often give way at feeders. In Florida, eastern gray squirrels, Florida scrub jays, common grackles and red-headed woodpeckers dominated them. Each of these was occasionally seen aggressively preventing the jays from feeding.
The mating season begins in mid-March, peaks from mid-April to May, and extends into July. Any suitable tree or large bush will do for a nest, though an evergreen is preferred. The nest is typically built 3 to 10 m up. The cup is made of twigs, small roots, bark strips, moss, other plant material, cloth, paper and feathers, with occasional mud.
Blue jays are not picky about where they nest. In heavily deforested areas they will use the large mailboxes typical of the rural United States. They also take over the nests of other mid-sized songbirds when these sit in suitable spots, and American robin nests are commonly used.
After fledging, the family travels and forages together until early fall. Then the young disperse, avoiding competition for food during the winter. Sexual maturity arrives after one year.
The oldest known wild banded blue jay was at least 26 years and 11 months old. It was banded in the Newfoundland, Labrador and Saint-Pierre et Miquelon area in 1989. It was found dead there in 2016, caught in fishing gear. A more common lifespan for wild birds that reach adulthood is around 7 years.
Predation and collisions with man-made objects take their toll. In recent decades, West Nile virus has also been a common cause of death, because corvids as a whole seem especially susceptible. Despite several major local declines, blue jays overall do not appear to have been depleted by the disease.
In old African-American folktales of the southern United States, the blue jay was a significant metaphysical creature. In some tales it made the earth "when all de worl' was water" by bringing the first "grit" or "dirt".
Other tales conscripted the blue jay, temporarily, as a servant of the Devil. It gathered twigs to furnish hell's kindling and give fire to wicked men on Earth, so it was not seen on Friday. Relieved from duty on Saturday, its song for the day was abundant and joyous.
In modern fiction, an anthropomorphic blue jay named Mordecai is one of the main characters of the Cartoon Network animated series Regular Show.
The province of Prince Edward Island in Canada has made the blue jay its provincial bird. Johns Hopkins University, Elmhurst University and Creighton University all use it as their official mascot.
The Toronto Blue Jays of Major League Baseball adopted the bird as their team symbol, as did some of their minor league affiliates. The team's mascot, Ace, is an anthropomorphic blue jay.
Continue browsing
Updated
Common questions
Why is the blue jay blue?
The blue jay's color comes from structural coloration, not pigment. Light interference caused by the internal structure of the feathers produces the blue, which is why a crushed blue feather loses its color. The actual pigment in the feathers is melanin.
Where does the blue jay live?
The blue jay lives in southern Canada and throughout the eastern and central United States, south to Florida and northeastern Texas. Its range generally stops at the eastern foothills of the Rocky Mountains, where the Steller's jay territory begins.
What does the blue jay eat?
The blue jay is omnivorous, and the Audubon Society estimates that 75% of its diet is vegetable matter. It eats acorns, beech mast, seeds, grain, fruit, berries and peanuts in the shell, along with small invertebrates and, rarely, eggs and nestlings.
Do blue jays migrate?
Some blue jays migrate, especially the northernmost subspecies, Cyanocitta cristata bromia. They travel by day in loose flocks of 5 to 250 birds, and some individuals migrate one year and stay north the next. No one has concretely worked out why they migrate when they do.
How long do blue jays live?
A common lifespan for a wild blue jay that survives to adulthood is around 7 years. The oldest known wild banded blue jay was at least 26 years and 11 months old, banded in 1989 and found dead in 2016.
How many subspecies of blue jay are there?
Four blue jay subspecies are generally accepted: the northern blue jay (bromia), the coastal blue jay (cristata), the interior blue jay (cyanotephra) and the Florida blue jay (semplei). The Florida blue jay is the smallest and the northern blue jay is the largest.
Why do blue jays mimic hawks?
Blue jays may copy the calls of red-tailed and red-shouldered hawks, possibly to test whether a hawk is nearby. They may also do it to scare off other birds that compete for food.
All sources
49 references cited across the entry
- 1Cyanocitta cristataBirdLife International — 2025
- 2NewsThe blue jays are coming! Hide yo kids, hide yo nuts!May 7, 2014
- 3Bird of the Week: Blue JayTravis Audubon — July 17, 2024
- 4Blue JayNational Audubon Society
- 5BookKey to North American birdsElliot Coues — Estes and Lauriat — 1890
- 6Bird of the Month: Blue JayMichaela Parker — Mississippi State University Extension
- 7BookNatural History of Carolina, Florida, and the BahamasMark Catesby — Royal Society House — 1731
- 8BookSystema Naturae per Regna Tria Naturae, Secundum Classes, Ordines, Genera, Species, cum Characteribus, Differentiis, Synonymis, Locis. Tomus I. Editio Decima, ReformataC. Linnaeus — Laurentius Salvius — 1758
- 9BookA geographical and comparative list of the birds of Europe and North AmericaCharles L. Bonaparte — J. Van Voorst — 1838
- 10BookBulletin of the National History Survey, Issues 4-6Chicago Academy of Sciences — 1900
- 11BookThe Scientific Nomenclature of Birds in the Upper MidwestJames Sandrock — University of Iowa Press — 2014
- 12JournalWeights and wing lengths in Connecticut Blue JaysS. D. Jewell — 1986
- 13JournalFall and winter birds near Homestead, FloridaE.J. Fisk — 1979
- 14What Color is a Bluejay?Anita Carpenter — February 2003
- 16JournalRange Extension of the Blue Jay into Western North AmericaSmith GH — 1978
- 17Tarvin KA, Woolfenden GE. (1999). "Blue Jay (Cyanocitta cristata)", no. 469. In: A. Poole (ed.). The Birds of North America Online. Cornell Lab of Ornithology, Ithaca, New York.
- 18JournalRange expansion of Barred Owls, part I: chronology and distributionKB Livezey — 2009
- 19JournalRange expansion of Barred Owls, part 2: facilitating ecological changesKB Livezey — 2009b
- 20JournalKilling Barred Owls to Help Spotted Owls II: Implications for Many Other Range-Expanding SpeciesLivezey KB — 2010
- 21Blue Jay Cyanocitta cristata BBS Trend Map, 1966 - 2015U.S. Department of the Interior
- 22JournalThe geographic races of Cyanocitta cristataHarry C. Oberholser — 1921
- 23JournalA new Blue Jay from the western border of the Great BasinGeorge Miksch Sutton — 1935
- 24JournalA new Blue Jay from Southern FloridaW. E. Clyde Todd — 1928
- 27JournalBlue Jays Mimic the Calls of Red-shouldered and Broad-winged HawksRoss D. James — 1988
- 28JournalBlue Jays Attack a Red BatWilliam M. Clay — 1959
- 29The Truth About Blue Jays – The Free Weekly30 March 2016
- 31JournalTool use by a wild Blue Jay ( Cyanocitta cristata )Lee C. Cash et al. — 2025
- 32Blue Jay Cyanocitta cristataNovember 13, 2014
- 37Longevity Records Of North American BirdsU. S. Geological Survey: Bird Banding Laboratory
- 38Animal facts: Blue JayThe Royal Canadian Geographical Society — July 26, 2006
- 39BookBirds in legend, fable and folkloreErnest Ingersoll — Longmans, Green and Co. — 1923
- 40BookOzark Magic and FolkloreVance Randolph — Courier Corporation — July 31, 2012
- 41Provincial BirdMay 26, 2015
- 44George, Philip Brandt. (2003). In: Baughman, Mel M. (ed.) Reference Atlas to the Birds of North America. National Geographic Society, Washington, D.C., p. 279,
- 45JournalA preliminary list of the birds of Seneca County, OhioW. F. Henninger — 1906
- 46JournalTool-Making and Tool-Using in the Northern Blue JayThony B. Jones et al. — 1973
- 47BookCrows and jays: a guide to the crows, jays and magpies of the worldSteve Madge et al. — A&C Black — 1994
- 48Blue JayCanadian Wildlife Service
- 49Blue Jay2007
- 50JournalExtinction by hybridization and introgressionJudith M. Rhymer et al. — 1996