Blue jay

Last updated

Contents

Blue jay
Temporal range: Piacenzian - present
Blue jay in PP (30960).jpg
In Prospect Park, Brooklyn, New York
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Corvidae
Genus: Cyanocitta
Species:
C. cristata
Binomial name
Cyanocitta cristata
Subspecies

4 sspp., see text

Cyanocitta cristata map.svg
Approximate distribution map
  Year-round
  Nonbreeding
Synonyms

Corvus cristatusLinnaeus, 1758

The blue jay (Cyanocitta cristata) is a passerine bird in the family Corvidae, native to eastern North America. It lives in most of the eastern and central United States; some eastern populations may be migratory. Resident populations are also in Newfoundland, Canada; breeding populations are found across southern Canada. It breeds in both deciduous and coniferous forests, and is common in residential areas. Its coloration is predominantly blue, with a white chest and underparts, and a blue crest; it has a black, U-shaped collar around its neck and a black border behind the crest. Males and females are similar in size and plumage, and plumage does not vary throughout the year. Four subspecies have been recognized.

The blue jay feeds mainly on seeds and nuts, such as acorns, which it may hide to eat later; [2] soft fruits; arthropods; and occasionally small vertebrates. It typically gleans food from trees, shrubs, and the ground, and sometimes hawks insects from the air. Blue jays can be very aggressive to other birds; they sometimes raid nests and have even been found to have decapitated other birds. [3]

It builds an open cup nest in the branches of a tree; both sexes participate. The clutch may be two to seven eggs, which are blueish or light brown with darker brown spots. Young are altricial, and are brooded by the female for 8–12 days after hatching. They may stay with their parents for one to two months.

The name jay derives from the bird's noisy, garrulous nature and has been applied to other birds of the same family, which are also mostly gregarious. [4] Jays are also called jaybirds. [5]

Taxonomy

The blue jay was first described as Pica glandaria cærulea cristata in English naturalist Mark Catesby's 1731 publication of Natural History of Carolina, Florida, and the Bahamas. [6] It was later described as Corvus cristatus in Carl Linnaeus' 1758 edition of Systema Naturae . [7] In the 19th century, the jay was described by French ornithologist Charles Lucien Bonaparte in 1838 as Cyanocorax cristatus in A geographical and comparative list of the birds of Europe and North America, [8] and given its modern scientific name Cyanocitta cristata by Hugh Edwin Strickland in 1845. [9] The genus name Cyanocitta derives from the Greek words kyaneos (blue) and the kitta and kissa (chattering bird, jay), and the term "blue chatterer" refers to the bright blue plumage of the head, nape, back, and tail of the bird. The specific name cristata (crested, tufted) derives from Latin referring to the prominent blue crest of the jay. [10]

Description

John James Audubon drawing circa 1830s 102 Blue Jay.jpg
John James Audubon drawing circa 1830s

The blue jay measures 22–30 cm (9–12 in) from bill to tail and weighs 70–100 g (2.5–3.5 oz), with a wingspan of 34–43 cm (13–17 in). [11] [12] Consistent with Bergmann's rule, jays from Connecticut averaged 92.4 g (3.26 oz) in mass, while jays from warmer southern Florida averaged 73.7 g (2.60 oz). [13] [14] There is a pronounced crest on the head, a crown of feathers, which may be raised or lowered according to the bird's mood. When excited or aggressive, the crest will be fully raised. When frightened, the crest bristles outwards, brushlike. When the bird is feeding among other jays or resting, the crest is flattened on the head. [15]

Its plumage is lavender-blue to mid-blue in the crest, back, wings, and tail, and its face is white. The underside is off-white and the neck is collared with black which 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 are almost identical, but the male is slightly larger. [12] [16] The black plumage on its nape, face, and throat varies extensively between individuals; it is believed to assist in recognition between individuals. [12]

As with most other blue-hued birds, the blue jay's coloration is not derived from pigments but is the result of light interference due to the internal structure of the feathers; [17] if a blue feather is crushed, the blue disappears because the structure is destroyed. The actual pigment in its feathers is melanin. [11] This is referred to as structural coloration.

Distribution and habitat

The blue jay occurs from southern Canada (including the southern areas of provinces from Alberta eastward to Quebec and throughout the Atlantic provinces) and throughout the eastern and central United States south to Florida and northeastern Texas. The western edge of the range stops where the arid pine forest and scrub habitat of the closely related Steller's jay (C. stelleri) begins, generally in the eastern foothills of the Rocky Mountains. Recently, the range of the blue jay has extended northwestwards so that it is now a rare but regularly seen winter visitor along the northern US and southern Canadian Pacific Coast. [11] As the two species' ranges now overlap, C. cristata may sometimes hybridize with Steller's jay. [18] The increase in trees throughout the Great Plains during the past century due to fire suppression and tree planting facilitated the western range expansion of the blue jay [19] [20] as well as range expansions of many other species of birds. [21] [22] [23] From 1966 to 2015, the Blue Jay experienced a population decline along the Atlantic coast, but a greater than 1.5% annual population increase throughout the northern part of its range, including Labrador, Nova Scotia, southern Quebec, and southern Manitoba. [24]

The northernmost subspecies C. c. bromia is migratory, subject to necessity. It may withdraw several hundred kilometers south in the northernmost parts of its range. Thousands of blue jays have been observed to migrate in flocks along the Great Lakes and Atlantic coasts. It migrates during the daytime, in loose flocks of 5 to 250 birds. Much about their migratory behavior remains a mystery. Some are present throughout winter in all parts of their range. Young jays may be more likely to migrate than adults, but many adults also migrate. Some individual jays migrate south one year, stay north the next winter, and then migrate south again the next year. To date, no one has concretely worked out why they migrate when they do. Likely, it is related to weather conditions and how abundant the winter food sources are, which can determine whether other northern birds will move south. [25]

The blue jay occupies a variety of habitats within its large range, from the pine woods of Florida to the spruce-fir forests of northern Ontario. It is less abundant in denser forests, preferring mixed woodlands with oaks and beeches. [15] It has expertly adapted to human activity, occurring in parks and residential areas, and can adapt to wholesale deforestation with relative ease if human activity creates other means for the jays to get by. [26]

Subspecies

Four subspecies are generally accepted, though the variation within this species is rather subtle and essentially clinal. No firm boundaries can be drawn between the inland subspecies. The ranges of the coastal races are better delimited. [16]

ImageSubspeciesCommon NameDescriptionDistribution
Blue Jay (14537080034).jpg Cyanocitta cristata bromiaOberholser, HC 1921Northern blue jayThe largest subspecies, with fairly dull plumage. Blue is rather pale.Canada and northern United States.
Blue Jay Ash RWD5.jpg Cyanocitta cristata cristataCoastal blue jayThe nominate subspecies, mid-sized and vivid blue.Coastal USA from North Carolina to Texas, except southern Florida
Cyanocitta cristata FWS.jpg Cyanocitta cristata cyanotephraSutton, GM 1935Interior blue jayMid-sized, quite dark blue on mantle contrasting cleanly with very white underside.Inland USA from SE Wyoming and Nebraska to west Kansas, Oklahoma and northern Texas, intergrading with C. c. bromia to the north.
Florida Bluejay Shows Off.jpg Cyanocitta cristata sempleiTodd, 1928Florida blue jayThe smallest subspecies, much like C. c. bromia in color.Southern Florida.

Behavior

Merlin chasing a blue jay MerlinchasingBlueJay08.jpg
Merlin chasing a blue jay

The blue jay is a noisy, bold, and aggressive passerine. It is a moderately slow flier (roughly 32–40 km/h or 20–25 mph) when unprovoked. [27] It flies with body and tail held level, with slow wing beats. Its slow flying speeds make this species easy prey for hawks and owls when it flies in open areas. Virtually all the raptorial birds sympatric in distribution with the blue jay may prey upon it, especially swift bird-hunting specialists such as the Accipiter hawks. Diverse predators may prey on jay eggs and young up to their fledgling stage, including tree squirrels, snakes, cats, crows, raccoons, opossums, other jays and possibly many of the same birds of prey who attack adults. [28]

The blue jay can be beneficial to other bird species, as it may chase predatory birds, such as hawks and owls, and will scream if it sees a predator within its territory. It has also been known to sound an alarm call when hawks or other dangers are near, and smaller birds often recognize this call and hide themselves away accordingly. It may occasionally impersonate the calls of raptors, especially those of the red-tailed and red-shouldered hawks, possibly to test whether a hawk is in the vicinity, though also possibly to scare off other birds that may compete for food sources. [25] It may also be aggressive towards humans who come close to its nest, and if an owl roosts near the nest during the daytime the blue jay mobs it until it takes a new roost. [29] However, blue jays have also been known to attack or kill other smaller birds, and foliage-roosting bat species such as Eastern red bats. [30] Jays are very territorial birds, and they will chase others from a feeder for an easier meal. Additionally, the blue jay may raid other birds' nests, stealing eggs, chicks, and nests. However, this may not be as common as is typically thought, as only 1% of food matter in one study was bird material. [25] Despite this, other passerines may still mob jays who come within their breeding territories.

When a blue jay is agitated or angry, the blue crest atop its head will rise. It will lower when the bird is relaxed or calm. [31]

Blue jay in flight C. c. bromia, in New York, NY.jpg
Blue jay in flight

Blue jays, like other corvids, are highly curious and are considered intelligent birds. Young individuals playfully snatch brightly coloured or reflective objects, such as bottle caps or pieces of aluminum foil, and carry them around until they lose interest. [29] While not confirmed to have engaged in tool use in the wild, blue jays in captivity have been observed using strips of newspaper as tools to obtain food, [25] [32] while captive fledglings have been observed attempting to open the doors of their cages. [33]

Diet

Blue jay cracking nuts

Blue jays are omnivorous, but the Audubon Society estimates that 75% of their diet is vegetable matter. [34] They have strong black bills which they use for cracking nuts, usually while holding them with their feet, and for eating corn, grains and seeds. Blue jays particularly love to eat peanuts in the shell. [35] Its food is sought both on the ground and in trees and includes virtually all known types of plant and animal sources, such as acorns and beech mast, weed seeds, grain, fruits and other berries, peanuts, bread, meat, small invertebrates of many types, scraps in town parks, bird-table food and rarely eggs and nestlings. [25] Blue jays will sometimes cache food, though to what extent differs widely among individuals. [36] Although seemingly contentious in their general behavior, blue jays are frequently subservient to other medium-sized birds who visit bird feeders. In Florida, blue jays were dominated at feeders by eastern gray squirrels, Florida scrub-jays, common grackles and red-headed woodpeckers, all of which were occasionally observed to aggressively prevent the jays from feeding. [25]

Reproduction

Blue Jays nest.jpg
Nest in the top of a little pine
Cyanocitta cristata MWNH 1384.JPG
Eggs, Collection Museum Wiesbaden

The mating season begins in mid-March, peaks in mid-April to May, and extends into July. Any suitable tree or large bush may be used for nesting, though an evergreen is preferred. The nest is preferentially built at a height in the trees of 3 to 10 m (10 to 33 ft). It is cup-shaped and composed of twigs, small roots, bark strips, moss, other plant material, cloth, paper, and feathers, with occasional mud added to the cup.

Juvenile vocalizing in July Blue jay fledgling (53513).jpg
Juvenile vocalizing in July

Blue jays are not very picky about nesting locations. If no better place is available – such as in a heavily deforested area – they will even use places like the large mailboxes typical of the rural United States. [26] They also appropriate nests of other mid-sized songbirds as long as these are placed in suitable spots; American robin nests are commonly used by blue jays, for example.

Fledgling in mid-June Blue Jay Cyanocitta cristata Fledgling.jpg
Fledgling in mid-June

Blue jays typically form monogamous pair bonds for life. Both sexes build the nest and rear the young, though only the female broods them. The male feeds the female while she is brooding the eggs. There are usually between 3 and 6 (averaging 4 or 5) eggs laid and incubated over 16–18 days. The young fledge usually between 17 and 21 days after hatching. [29]

After the juveniles fledge, the family travels and forages together until early fall, when the young birds disperse to avoid competition for food during the winter. Sexual maturity is reached after one year of age. The oldest known wild, banded Blue Jay was at least 26 years, 11 months old when it was found dead after being caught in fishing gear. It had been banded in the Newfoundland/Labrador/Saint-Pierre et Miquelon area in 1989 and was found there in 2016. [37] Another wild jay was found to have been around 17+12 years old. [38] A more common lifespan for wild birds that survive to adulthood is around 7 years. [39] Beyond predation and the occasional collision with man-made objects, a common cause of mortality in recent decades has been the West Nile virus, to which corvids as a whole seem especially susceptible. However, despite several major local declines, overall blue jays have not seemed to have been depleted by the disease. [28]

Vocalizations

Blue jays can make a large variety of sounds, and individuals may vary perceptibly in their calling style. Like other corvids, they may learn to mimic human speech. Blue jays can also copy the cries of local hawks so well that it is sometimes difficult to tell which it is. [40] Their voice is typical of most jays in being varied, but the most commonly recognized sound is the alarm call, which is a loud, almost gull-like scream. There is also a high-pitched jayer-jayer call that increases in speed as the bird becomes more agitated. This particular call can be easily confused with the chickadee's song because of the slow-starting chick-ah-dee-ee. Blue jays will use these calls to band together to mob potential predators such as hawks and drive them away from the jays' nests.

In human culture

In old African-American folktales of the southern United States, the blue jay was a significant metaphysical creature. In some tales, the blue jay was credited with making the earth "when all de worl' was water" by bringing the first "grit" or "dirt." In other tales the blue jay was temporarily conscripted as a servant of the devil and would not be seen on Friday as it was gathering twigs to furnish hell's kindling and give fire to wicked men on Earth; relieved from duty on Saturday, its song for the day was abundant and joyous. [41] [42]

The blue jay was adopted as the team symbol of the Toronto Blue Jays Major League Baseball team, as well as some of their minor league affiliates. Their mascot, Ace, is an anthropomorphic blue jay. The blue jay is also the official mascot for Johns Hopkins University, Elmhurst University, and Creighton University. It is also the provincial bird of the province of Prince Edward Island in Canada. [43]

Related Research Articles

<span class="mw-page-title-main">American crow</span> Species of bird

The American crow is a large passerine bird species of the family Corvidae. It is a common bird found throughout much of North America. American crows are the New World counterpart to the carrion crow and the hooded crow of Eurasia; they all occupy the same ecological niche. Although the American crow and the hooded crow are very similar in size, structure and behavior, their calls and visual appearance are different.

<span class="mw-page-title-main">Steller's jay</span> Species of bird found in western North America

Steller's jay is a bird native to western North America and the mountains of Central America, closely related to the blue jay found in eastern North America. It is the only crested jay west of the Rocky Mountains. It is also sometimes colloquially called a "blue jay" in the Pacific Northwest, but is distinct from the blue jay of eastern North America. The species inhabits pine-oak and coniferous forests.

<span class="mw-page-title-main">Fish crow</span> Species of bird

The fish crow is a species of crow associated with wetland habitats in the eastern and southeastern United States.

<span class="mw-page-title-main">Eastern bluebird</span> Species of bird

The eastern bluebird is a small North American migratory thrush found in open woodlands, farmlands, and orchards.

<span class="mw-page-title-main">Pileated woodpecker</span> Species of bird

The pileated woodpecker is a large, mostly black woodpecker native to North America. An insectivore, it inhabits deciduous forests in eastern North America, the Great Lakes, the boreal forests of Canada, and parts of the Pacific Coast. It is the largest confirmed extant woodpecker species in North America, with the possible exception of the ivory-billed woodpecker, which the U.S. Fish and Wildlife Service has proposed be reclassified as extinct. It is also the third largest species of woodpecker in the world, after the great slaty woodpecker and the black woodpecker. "Pileated" refers to the bird's prominent red crest, from the Latin pileatus meaning "capped".

<span class="mw-page-title-main">Barred owl</span> Species of owl

The barred owl, also known as the northern barred owl, striped owl or, more informally, hoot owl or eight-hooter owl, is a North American large species of owl. A member of the true owl family, Strigidae, they belong to the genus Strix, which is also the origin of the family's name under Linnaean taxonomy. Barred owls are largely native to eastern North America, but have expanded their range to the west coast of North America where they are considered invasive. Mature forests are their preferred habitat, but they can also acclimatise to various gradients of open woodlands. Their diet consists mainly of small mammals, but this species is an opportunistic predator and is known to prey upon other small vertebrates such as birds, reptiles, and amphibians, as well as a variety of invertebrates.

<span class="mw-page-title-main">Northern saw-whet owl</span> Species of owl

The northern saw-whet owl is a species of small owl in the family Strigidae. The species is native to North America. Saw-whet owls of the genus Aegolius are some of the smallest owl species in North America. They can be found in dense thickets, often at eye level, although they can also be found some 20 ft (6.1 m) up. Saw-whets are often in danger of being preyed upon by larger birds of prey. The northern saw-whet owl is a migratory bird without any strict pattern.

<span class="mw-page-title-main">Eastern screech owl</span> Species of owl

The eastern screech owl or eastern screech-owl, is a small owl that is relatively common in Eastern North America, from Mexico to Canada. This species resides in most types of woodland habitats across its range, and is relatively adaptable to urban and developed areas compared to other owls. Although it often lives in close proximity to humans, the eastern screech owl frequently avoids detection due to its strictly nocturnal habits.

<span class="mw-page-title-main">Canada jay</span> Passerine bird of the family Corvidae

The Canada jay, also known as the gray jay, grey jay, camp robber, or whisky jack, is a passerine bird of the family Corvidae. It is found in boreal forests of North America north to the tree line, and in the Rocky Mountains subalpine zone south to New Mexico and Arizona. A fairly large songbird, the Canada jay has pale grey underparts, darker grey upperparts, and a grey-white head with a darker grey nape. It is one of three members of the genus Perisoreus, a genus more closely related to the magpie genus Cyanopica than to other birds known as jays. The Canada jay itself has nine recognized subspecies.

<span class="mw-page-title-main">Cooper's hawk</span> Species of bird

Cooper's hawk is a medium-sized hawk native to the North American continent and found from southern Canada to Mexico. This species is a member of the genus Accipiter, sometimes referred to as true hawks, which are famously agile, relatively small hawks common to wooded habitats around the world and also the most diverse of all diurnal raptor genera. As in many birds of prey, the male is smaller than the female. The birds found east of the Mississippi River tend to be larger on average than the birds found to the west. It is easily confused with the smaller but similar sharp-shinned hawk.

<span class="mw-page-title-main">Red-tailed hawk</span> Species of bird

The red-tailed hawk is a bird of prey that breeds throughout most of North America, from the interior of Alaska and northern Canada to as far south as Panama and the West Indies. It is one of the most common members within the genus of Buteo in North America or worldwide. The red-tailed hawk is one of three species colloquially known in the United States as the "chickenhawk", though it rarely preys on standard-sized chickens. The bird is sometimes also referred to as the red-tail for short, when the meaning is clear in context. Red-tailed hawks can acclimate to all the biomes within their range, occurring on the edges of non-ideal habitats such as dense forests and sandy deserts. The red-tailed hawk occupies a wide range of habitats and altitudes, including deserts, grasslands, coniferous and deciduous forests, agricultural fields, and urban areas. Its latitudinal limits fall around the tree line in the subarctic and it is absent from the high Arctic. Generally it favors varied habitats with open woodland, woodland edge and open terrain. It is legally protected in Canada, Mexico, and the United States by the Migratory Bird Treaty Act.

<span class="mw-page-title-main">Rose-breasted grosbeak</span> Species of bird

The rose-breasted grosbeak, colloquially called "cut-throat" due to its coloration, is a large, seed-eating grosbeak in the cardinal family (Cardinalidae). It is primarily a foliage gleaner. Males have black heads, wings, backs, and tails, and a bright rose colored patch on their white breast. Males and females exhibit marked sexual dimorphism.

<span class="mw-page-title-main">Scarlet tanager</span> Species of bird

The scarlet tanager is a medium-sized American songbird. Until recently, it was placed in the tanager family (Thraupidae), but it and other members of its genus are now classified as belonging to the cardinal family (Cardinalidae). The species' plumage and vocalizations are similar to other members of the cardinal family, although the Piranga species lacks the thick conical bill that many cardinals possess. The species resides in thick deciduous woodlands and suburbs.

<span class="mw-page-title-main">Eastern phoebe</span> Species of bird

The eastern phoebe is a small passerine bird. The genus name Sayornis is constructed from the specific part of Charles Lucien Bonaparte's name for Say's phoebe, Muscicapa saya, and Ancient Greek ornis, "bird". Phoebe is an alternative name for the Roman moon-goddess Diana, but it may also have been chosen to imitate the bird's call.

<span class="mw-page-title-main">Western kingbird</span> Species of bird

The western kingbird is a large tyrant flycatcher found throughout western environments of North America, as far south as Mexico.

<span class="mw-page-title-main">Yellow warbler</span> Species of bird

The yellow warbler is a New World warbler species. Yellow warblers are the most widespread species in the diverse genus Setophaga, breeding in almost the whole of North America, the Caribbean, and down to northern South America.

<span class="mw-page-title-main">California scrub jay</span> Species of bird in the crow family

The California scrub jay is a species of scrub jay native to western North America. It ranges from southern British Columbia throughout California and western Nevada near Reno to west of the Sierra Nevada. The California scrub jay was once lumped with Woodhouse's scrub jay and collectively called the western scrub jay. The group was also lumped with the island scrub jay and the Florida scrub jay; the taxon was then called simply scrub jay. The California scrub jay is nonmigratory and can be found in urban areas, where it can become tame and will come to bird feeders. While many refer to scrub jays as "blue jays", the blue jay is a different species of bird entirely.

<span class="mw-page-title-main">Brown thrasher</span> Species of bird

The brown thrasher, sometimes erroneously called the brown thrush or fox-coloured thrush, is a bird in the family Mimidae, which also includes the New World catbirds and mockingbirds. The brown thrasher is abundant throughout the eastern and central United States and southern and central Canada, and it is the only thrasher to live primarily east of the Rockies and central Texas. It is the state bird of Georgia.

<span class="mw-page-title-main">Woodhouse's scrub jay</span> Species of bird

Woodhouse's scrub jay is a species of scrub jay native to western North America, ranging from southeastern Oregon and southern Idaho to central Mexico. Woodhouse's scrub jay was until recently considered the same species as the California scrub jay, and collectively called the western scrub jay. Prior to that both of them were also considered the same species as the island scrub jay and the Florida scrub jay; the taxon was then called simply the scrub jay. Woodhouse's scrub jay is nonmigratory and can be found in urban areas, where it can become tame and will come to bird feeders. While many refer to scrub jays as "blue jays", the blue jay is a different species of bird entirely. Woodhouse's scrub jay is named for the American naturalist and explorer Samuel Washington Woodhouse.

References

  1. BirdLife International (2016). "Cyanocitta cristata". IUCN Red List of Threatened Species . 2016: e.T22705611A94027257. doi: 10.2305/IUCN.UK.2016-3.RLTS.T22705611A94027257.en . Retrieved 25 June 2022.
  2. "The blue jays are coming! Hide yo kids, hide yo nuts!". Seriously, Science?.
  3. Little Known Fact: Blue Jays are Vicious Carnivores. pedaldrivenprogramming.com (15 Apr 2008)
  4. Coues, Elliot (1890). Key to North American birds (5th ed.). Boston, MA: Estes and Lauriat. p. 326. OCLC   469020022.
  5. "jaybird – definition of jaybird by the Free Online Dictionary, Thesaurus and Encyclopedia" . Retrieved April 20, 2011.
  6. Catesby, Mark (1731). Natural History of Carolina, Florida, and the Bahamas (1st ed.). London: Royal Society House. p. 87.
  7. Linnaeus, C. (1758). Systema Naturae per Regna Tria Naturae, Secundum Classes, Ordines, Genera, Species, cum Characteribus, Differentiis, Synonymis, Locis. Tomus I. Editio Decima, Reformata (in Latin). Vol. 1. Holmiae: Laurentius Salvius. p. 106.
  8. Bonaparte, Charles L. (1838). A geographical and comparative list of the birds of Europe and North America. London: J. Van Voorst. p. 27.
  9. Bulletin of the National History Survey, Issues 4-6. Chicago: Chicago Academy of Sciences. 1900. p. 120.
  10. Sandrock, James (2014). The Scientific Nomenclature of Birds in the Upper Midwest. University of Iowa Press. p. 48. ISBN   978-1609382254.
  11. 1 2 3 Blue Jay, Life History, All About Birds. Cornell Lab of Ornithology
  12. 1 2 3 "ADW: Cyanocitta cristata: INFORMATION". Animal Diversity Web.
  13. Jewell, S. D. (1986). "Weights and wing lengths in Connecticut Blue Jays". Connecticut Warbler. 6 (4): 47–49.
  14. Fisk, E.J. (1979). "Fall and winter birds near Homestead, Florida". Bird-Banding. 50 (3): 224–303. doi:10.2307/4512458. JSTOR   4512458.
  15. 1 2 "Blue Jay". Canadian Wildlife Service. Archived from the original on 2009-02-04. Retrieved 2009-08-09.
  16. 1 2 Madge, Steve; Burn, Hilary (1994). Crows and jays: a guide to the crows, jays and magpies of the world. London: A&C Black. ISBN   978-0-7136-3999-5.
  17. Carpenter, Anita (February 2003). "What Color is a Bluejay?". Wisconsin Natural Resources Magazine. Archived from the original on 2018-07-31. Retrieved 2012-10-21.
  18. Rhymer, Judith M.; Simberloff, Daniel (1996). "Extinction by hybridization and introgression". Annu. Rev. Ecol. Syst. 27: 83–109. doi:10.1146/annurev.ecolsys.27.1.83.
  19. Smith GH (1978). "Range Extension of the Blue Jay into Western North America" (PDF). Bird-Banding. 49 (3): 208–214. doi:10.2307/4512360. JSTOR   4512360.
  20. Tarvin 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.
  21. Livezey, KB (2009). "Range expansion of Barred Owls, part I: chronology and distribution". American Midland Naturalist. 161: 49–56. doi:10.1674/0003-0031-161.1.49. S2CID   86276981.
  22. Livezey, KB (2009b). "Range expansion of Barred Owls, part 2: facilitating ecological changes". American Midland Naturalist. 161 (2): 323–349. doi:10.1674/0003-0031-161.2.323. S2CID   84426970.
  23. Livezey KB (2010). "Killing Barred Owls to Help Spotted Owls II: Implications for Many Other Range-Expanding Species". Northwestern Naturalist. 91 (3): 251–270. doi:10.1898/NWN09-38.1. JSTOR   40983223. S2CID   85425945.
  24. "Blue Jay Cyanocitta cristata BBS Trend Map, 1966 - 2015". USGS. U.S. Department of the Interior. Retrieved 2020-12-09.
  25. 1 2 3 4 5 6 Blue Jay. birds.cornell.edu
  26. 1 2 Henninger, W. F. (1906). "A preliminary list of the birds of Seneca County, Ohio" (PDF). Wilson Bulletin . 18 (2): 47–60.
  27. Animal Speeds. Texas Parks & Wildlife. Retrieved July 1, 2008.
  28. 1 2 "ADW: Cyanocitta cristata: INFORMATION". Animal Diversity Web.
  29. 1 2 3 "Blue Jay". Archived from the original on 2007-05-02.
  30. Clay, William M. (1959). "Blue Jays Attack a Red Bat" (PDF). The Auk. 76 (4): 532. doi:10.2307/4082327. JSTOR   4082327.
  31. "The Truth About Blue Jays – The Free Weekly" . Retrieved 2019-09-08.
  32. Jones, Thony B.; Kamil, Alan C. (1973). "Tool-Making and Tool-Using in the Northern Blue Jay". Science . 180 (4090): 1076–1078. Bibcode:1973Sci...180.1076J. doi:10.1126/science.180.4090.1076. PMID   17806587. S2CID   22011846.
  33. American Rivers Archived 2013-12-18 at the Wayback Machine . tumblr.com
  34. "Blue Jay Cyanocitta cristata". Audubon.org. 13 November 2014.
  35. "Blue jays love peanuts in the shell".
  36. AllAboutBirds.org – Blue Jay The Cornell Lab of Ornithology
  37. "Blue Jay Overview, All About Birds, Cornell Lab of Ornithology".
  38. "Longevity Records Of North American Birds". U. S. Geological Survey: Bird Banding Laboratory. Retrieved 24 December 2012.
  39. "Animal facts: Blue Jay". Canadian Geographic. The Royal Canadian Geographical Society. July 26, 2006. Archived from the original on February 4, 2019. Retrieved February 3, 2019.
  40. George, Philip Brandt. (2003). In: Baughman, Mel M. (ed.) Reference Atlas to the Birds of North America. National Geographic Society, Washington, D.C., p. 279, ISBN   978-0-7922-3373-2
  41. Ingersoll, Ernest (1923). Birds in legend, fable and folklore. New York: Longmans, Green and Co. pp.  166–167. Retrieved 2009-08-08.
  42. Randolph, Vance (2012-07-31). Ozark Magic and Folklore. Courier Corporation. ISBN   978-0-486-12296-0.
  43. "Provincial Bird". Prince Edward Island. 26 May 2015. Retrieved 1 February 2024.