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Cyanocitta cristatablue jay

By Jake Frysinger

Ge­o­graphic Range

Blue jays are na­tive to the Nearc­tic re­gion. They are com­mon in south­ern Canada and in the United States, east of the Rocky Moun­tains. (San­ford 1984)

Habi­tat

Blue jays pre­fer mixed wood­lands, par­tic­u­larly those with clear­ings. They are also com­mon in sub­ur­ban areas and city parks. (Reilly 1968)

Phys­i­cal De­scrip­tion

Blue jays are bright blue on top and whitish gray on the belly and chin. They have a gray-blue, feather crested head, which they can raise and lower. The feath­ers on their wings and tails are bright blue with white and black bands. Blue jays also have a col­lar of black feath­ers across the throat and con­tin­u­ing around the head. Their bills, legs, feet, and eyes are black. Males are just a lit­tle larger, on av­er­age, than fe­males. Total body length ranges from 22 to 30 cm. (Reilly 1968)

  • Sexual Dimorphism
  • male larger
  • Range mass
    65 to 109 g
    2.29 to 3.84 oz
  • Range length
    22 to 30 cm
    8.66 to 11.81 in

Re­pro­duc­tion

Blue jays form long-last­ing, monog­a­mous pair bonds. These bonds usu­ally last until one of the pair dies.

Blue jays build loose and un­tidy nests of barks, twigs, leaves, and grasses in trees and shrubs. The fe­male lays three to six eggs at a time. These can be blue, green, or yel­low, with brown or grey spots. The eggs must be in­cu­bated for 17 to 18 days. This is usu­ally done by fe­male, but in some cases males share in the in­cu­ba­tion. Males pro­vide food for fe­males dur­ing in­cu­ba­tion. Young fledge after 17 to 21 days and leave their natal range about 2 months after fledg­ing. Blue jays may breed in their first year after hatch­ing. (Zims 1956, Reilly 1968)

  • Breeding interval
    In the north, only one brood per year may be produced. In southern regions, however, Blue Jays may raise two broods each year.
  • Breeding season
    Blue Jays breed from March through July.
  • Range eggs per season
    3 to 6
  • Average eggs per season
    4
    AnAge
  • Average time to hatching
    17 days
  • Average time to hatching
    17 days
    AnAge
  • Range fledging age
    17 to 21 days
  • Average time to independence
    3 months
  • Average age at sexual or reproductive maturity (female)
    1 years
  • Average age at sexual or reproductive maturity (male)
    1 years

Both males and fe­males feed their nestlings. Young are able to feed them­selves three weeks after they leave the nest, but stay with their par­ents for around two months after fledg­ing.

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • protecting
      • male
      • female
  • pre-weaning/fledging
    • provisioning
      • male
      • female
    • protecting
      • male
      • female

Lifes­pan/Longevity

The old­est blue jay stud­ied by re­searchers in the wild lived to be 17 years and 6 months old, most blue jays live to about 7 years old. One cap­tive fe­male lived for 26 years and 3 months.

  • Range lifespan
    Status: wild
    17.5 (high) years
  • Range lifespan
    Status: captivity
    26.25 (high) years
  • Average lifespan
    Status: wild
    7 years
  • Average lifespan
    Status: wild
    210 months
    Bird Banding Laboratory

Be­hav­ior

Blue jays are very ag­gres­sive and noisy birds,dri­ving other birds away from food sources and their ter­ri­to­ries. In the win­ter, Blue jays hide far more food than they can eat, per­haps to re­move food from their ter­ri­to­ries to dis­cour­age in­trud­ers. They are also par­tially mi­gra­tory, and in the fall they can be seen trav­el­ing in flocks of more than a hun­dred birds. (San­ford 1984)

Com­mu­ni­ca­tion and Per­cep­tion

Blue jays use bob­bing mo­tions when court­ing and when fight­ing. A sig­nal of sub­mis­sion may be the "body-fluff" when the bird crouches down and fluffs up its feath­ers, hold­ing the crest erect.

Blue jays have many calls. The one that is prob­a­bly most fa­mil­iar is the "jay" call for which it is named. This prob­a­bly at­tracts other jays to join a flock or serves as an alarm call. An­other call sounds like a rusty pump han­dle, and an­other sounds like a bell. Blue jays also make rat­tling sounds. In the spring you can hear very soft singing.

Food Habits

Blue jays are om­niv­o­rous. They feed on fruits, nuts, seeds, in­sects, mice, frogs, and will rob other nests for small song­birds and bird eggs. To eat nuts, blue jays hold them with their feet and then crack the shell with their bill. Blue jays in cap­tiv­ity have been known to fash­ion tools in order to get at foods. Blue jays will also steal foods from other birds by fright­en­ing them into drop­ping what they have. They cache foods, such as seeds, for later use. (Reilly 1968)

  • Animal Foods
  • birds
  • mammals
  • amphibians
  • reptiles
  • eggs
  • insects
  • terrestrial non-insect arthropods
  • Plant Foods
  • seeds, grains, and nuts
  • fruit

Pre­da­tion

Blue jays will ac­tively de­fend their nests against preda­tors. Both par­ents will at­tack and chase hawks, fal­cons, rac­coons, cats, snakes, squir­rels, and even hu­mans away from their nests. Adult blue jays are often preyed on by var­i­ous species of hawks, owls, and fal­cons. Nestlings are preyed upon by squir­rels, cats, snakes, Amer­i­can crows, other jays, rac­coons, opos­sums, and birds of prey, such as hawks.

Ecosys­tem Roles

Be­cause they hide seeds and nuts and some­times for­get to find and eat them, these birds prob­a­bly help plants dis­perse their seeds.

  • Ecosystem Impact
  • disperses seeds

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Blue jays are ac­tive and bold birds, mak­ing it easy to ob­serve their fas­ci­nat­ing be­hav­iors.

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There are no di­rect neg­a­tive ef­fects of blue jays on hu­mans, al­though they may act as a reser­voir for West Nile virus.

Con­ser­va­tion Sta­tus

Blue jay pop­u­la­tions are on the rise, and they are often very com­mon where they occur. The range is ex­pand­ing west­ward. Pop­u­la­tions may have suf­fered some­what in pre­vi­ous cen­turies as their wooded habi­tats were cleared and may suf­fer where epi­demics of West Nile virus af­fect bird pop­u­la­tions. Blue jays are corvids, which seem par­tic­u­larly sus­cep­ti­ble to this virus. (Reilly 1968)

Other Com­ments

Blue jays have been cho­sen as the mas­cot for many sports teams, in­clud­ing the Toronto Blue Jays, a pro­fes­sional base­ball team.

(Reilly 1968)

Con­trib­u­tors

Tanya Dewey (ed­i­tor), An­i­mal Di­ver­sity Web.

Jake Frysinger (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

acoustic

uses sound to communicate

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

diurnal
  1. active during the day, 2. lasting for one day.
endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

migratory

makes seasonal movements between breeding and wintering grounds

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

omnivore

an animal that mainly eats all kinds of things, including plants and animals

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

stores or caches food

places a food item in a special place to be eaten later. Also called "hoarding"

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

visual

uses sight to communicate

Ref­er­ences

Reilly, Edgar M. Jr. 1968. The Audubon Il­lus­trated Hand­book of Amer­i­can Birds. Mc­Graw-Hill, New York. pp.307-308.

San­ford, William F. 1984. Aca­d­e­mic Amer­i­can En­cy­lo­pe­dia. Grolier In­cor­po­rated, Con­necti­cut. p.343.

Zim, Her­bert S. and Ira N. Gabriel­son. 1956. Birds: A guide to the most fa­mil­iar Amer­i­can birds. Golden Press, New York. pp.76, 142.

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Classification

  • Kingdom Animalia animals
  • Phylum Chordata chordates
  • Subphylum Vertebrata vertebrates
  • Class Aves birds
  • Order Passeriformes perching birds
  • Family Corvidae crows and jays
  • Genus Cyanocitta blue jays
  • Species Cyanocitta cristata blue jay