The secret and baffling life of the blue jay

I wake every morning to a few birds swooping around the oak tree and shrubs lining the fence in my backyard. One of the most common residents is Cyanocitta cristata, or the blue jay. It may well be that these brilliant colored birds are the only ones I recognize in my early morning daze. The blue jay is white-breasted with blue feathers. It has a distinguishing blue crest, black collar, and black beak, with plumage that does not vary with sex or season. As I pour myself a cup of coffee, my roommate and I watch the magnificent-looking bird perch on a tree branch, then swoop down and chase off a smaller bird.

Like all members of the corvid family (crows and ravens), the blue jay has a fairly complicated social system. However, in comparison to other New Word jays it is relatively simple. As Racine and Thompson discuss, for the most part, blue jays are monogamous and so the breeding pair forms the cornerstone of the social structure. However, blue jays are not territorial and so it is not uncommon to find multiple pairs of jays sharing the same feeding ground. Oddly enough, blue jays will form large flocks toward the end of breeding season (late summer). Many jays from the northern US will migrate south during the winter. However, there is a small group that stays throughout the year. In a bird sanctuary in central Massachusetts, Racine and Thompson found that groups of blue jays form stable groups during the winter. Banded jays returned to the same feeding station over successive winters. Further, the offspring of known banded jays also returned to the same feeding station. Racine and Thompson speculate that the group bonding extends beyond feeding behavior. Even with alternative feeding stations, the same jays returned to the original location. The migratory patterns on blue jays are not well understood. Stewart found in his meta-analysis of over 8,000 recaptured blue jays in banding stations in the Atlantic Flyway (Florida, Massachusetts, New Jersey, and New York), there is no one defining factor determining which jays migrate south and which stay in their nesting area. As he discusses, the migration pattern of the blue jay is under dispute. Some ornithologists asserting that young jays predominantly migrate in hopes of having better luck finding food during the winter months, but other ornithologists claiming that older and younger jays migrate at equal rates.

Males are almost exclusively the dominant members of the breeding pair. Tarvin and Woolfendon’s four-year study looking at the dominance behavior of blue jays in south-central Florida found that of 316 interactions between males and females, less than 1% were won by the female. In general, males are larger than females and this difference in body size may be responsible for their unwavering victories. However, the authors noted that in this study, the males were only 5% bigger in most of the measured characteristics. They attribute the dominance to the males more aggressive nature. Males are more likely, in general, to be involved in interactions. Interestingly enough, immediately before breeding season (March), males became markedly less aggressive and females became more aggressive. The authors attribute this to “nesting phenology” and a shift in the energy demands as females needed to consume more nutrients for the nesting season. This did not shift the dominance, though, and females were still subordinate to males. It is very hard for me to see this hierarchy from my window, though, because from a distance, male and female blue jays look exactly the same. In fact, many professional ornithologists cannot even tell the difference without an up-close inspection!

One of the most interesting aspects of the blue jay is its resourcefulness. One study found that blue jays raised in a lab at the University of Massachusetts were able to make and use a tool to gather food. First, a single jay used pieces of newspaper lining the bottom of the cage to gather food pellets, otherwise out of reach with its beak. When presented with a paper clip, plastic bag tie, feather, and straw grass, the bird was able to successfully use these as tools to gather the out-of-reach food pellet. When the researches presented the other jays in the colony with the same materials, they found that 6 out of the 8 blue jays were able to use tools to gather food in the same manner. Fascinating!

Blue jays have a variety of calls and have been known to imitate other bird’s calls. Lofton and Clench report two such examples in Florida and Texas, respectively. In each case, a blue jay imitated a red-shouldered hawk in an effort to con other birds out of their food. The blue jay perched near a feeding bird and mimicked the hawk’s call. The bird feeding heard the call, thought a hawk was nearby, and flew away. The blue jay then swooped down and ate the food left by the bird. It is not know if Jays developed this unique ability mainly as a protective measure to warn others that a hawk is in close proximity or solely as a manipulative devise. Either way, it is very clever.

Typically, I only think of squirrels as collecting and storing nuts. Apparently, birds do this too. Johnson discusses the blue jay’s active role in distributing nuts. As a conservative estimate, he cites that 5-6% of a nut crop may be dispersed by jays. In fact, many researches consider the blue jay as primarily responsible for the widespread dispersal of certain beech trees after the glacial period in the eastern US. Blue jays routinely collect nuts and acorns and cache them in the ground for a later date when food is scarce. A single jay may cache many thousand nuts each year. Jays will forget about the food they stored and the nuts germinate and grow, extending the tree population up to several hundred meters per year. Blue jays are odd amongst birds that practice this behavior because they will transport the nuts several thousand meters!

My high school mascot was a blue jay and I used to think it was rather weak in comparison to large mammals and birds of prey. Now, though, I have gained a newfound respect for the blue jay. Although not always highly regarded by ornithologists because of their domineering behavior and mimicry calls (which can be confusing if you are actually looking for a hawk!), the blue jay leads an interesting, but not well-understood life. I used to admire them only for their beautiful blue plumage. Now, I am going to pay much more attention to the finer points of their behavior as I watch them flying around in my backyard while drinking my morning coffee.


Stewart PA. 1982. Migration of Blue jays in eastern North America. North American Bird Bander 7:107-112.

  • This paper describes the migrations patterns of blue jays from north to south. It discusses possible reasons why most blue jays are partly migratory.

Racine RN and Thompson NS. 1983. Social organization of wintering blue jays. Behaviour 87:237-255.

  • This paper discusses the group formation of blue jays during the fall and winter months as opposed to mating pairs in the spring and summer.

Tarvin KA and Woolfenden GE. 1997. Patterns of dominance and aggressive behavior in blue jays at a feeder. Condor 99:434-444.

  • This paper discusses a study conducted on the dominance behaviors among blue jays. I mainly pulled from the male-female interactions section.

Jones, T.B. and Kamil, A.C. 1973. Tool-making and tool-using in the northern blue jay. Science 180, p. 1076-1078.

  • This paper describes a case of blue jays using tools in the lab to gather food outside of their cage.

Lofton, RW. 1991. Blue jay imitates hawk for kleptoparasitism. Fla. Field Nat. l9(2): 55. 1991.

  • This paper and next describe case reports of blue jays imitating birds of prey in order to scare birds and steal their food.

Clench, MH. 1991. Another case of blue jay kleptoparasitism. Fla. Field Nat. 19(4): 109-110.

Johnson, W.C. and Webb, T. III. 1989. The role of blue jays (Cyanocitta cristata) in the postglacial dispersal of fagaceous trees in eastern North America. Journal of Biogeography16: 561–571.

  • This paper talks about the integral part blue jays play in spreading acorns and nuts of certain tree species while they cache food.

Table from University of South Florida study (Tarvin & Woolfenden, 1997) on dominance relationships in blue jays. Males are almost exclusively dominant over the females. However, males are also much more often involved in interactions with both females and other males.

Figure from University of Massachusetts study on blue jay tool use (Jones & Kamil, 1973) depicting the frequency of tool use as a function of time (food deprivation). Circles represent type of behavior (solid is paper manipulation, divided is thrusting the paper through the cage). Line type denotes presence of food (food is present outside the cage with solid lines, no food pellets were present with dashed line). Blue jays become most resourceful when food is present and they are hungry.

Blue jay using paper as a tool to gather food outside the cage (Jones & Kamil, 1973)

A map of the blue jay’s distribution throughout the United States: yellow is summer-only, blue is winter-only, and green is year-round.

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15 Responses to The secret and baffling life of the blue jay

  1. cory says:

    were raising a baby blue jay here in CA, this bird is awesome but very time consuking, weve had it since it was about 7 weeks old and it is now about 15 weeks, learning to fly and socialize. Indeed these birds are very smart and very loving im looking for more information on their social abilities

  2. Geochelone carbonari says:

    Most of the time, I have 3 distinct blue jays,, I know each one by their call, this morning, had 7 and the calls, were different,, two of them, were calling back and forth, with the same cue,, then, I saw the Coopers` Hawk,, January 21st, 2015

    Geochelone Carbonari,, Project Feeder Watch 2015 participant

  3. Johnnie Hall says:

    I have seen a blue jay at my platform feeder picking up a sunflower seed then placing it under his toes while he uses his beak to break it open and eat the heart. I have not seen any other birds doing this. The cardinals seem to have the ability to break open the sunflower seed with their beaks without having to place it under their toes and hammer it open.

  4. Pete Czar says:

    I have been cultivating a relationship with three Blue Jays, feeding them roasted peanuts. One I call Eli ( After Eli Manning, because Eli Manning lifts his leg just before the snap), well Eli the Jay sits on a branch puffs out his/her breast feathers, I give a chirping sound and he flies over and grabs the peanut from my fingers, pretty cool huh? Also I always thought there was a Red Tailed Hawk around, and thinking what a dummy announcing it’s presence, when I discovered that a Jay was making the sound. I know this because it was 5-6 ft away.

  5. Kim says:

    My cat is a rather avid hunter and will hunt all birds, much to my dismay. He has caught full grown grackles (and brought them in the house alive). That was interesting, to say the least. Got it out, and it survived. One thing he has never caught is a blue jay. They protect not only their own, they will gang up on my cat to protect ANY bird or rodent he has caught. I always know when he has caught something. They shriek very loudly and attack him. Now that fall has come to Long Island, I noticed that the scabs on my cats ears have healed. Meaning the blue jays have all gone. I’m sorry to see this because now the rest of the bird population should watch out. They are extremely smart and will be missed. Just not by my cat.

  6. Andree Dubreuil trois-rivieres, quebec says:

    I have hundreds. of such storries,, blue jays.. are very intelligent birds.. and,, 8 years later,, convinced me.. that, the same subjects, were indeed the same.. How.. we underestimate,, their cues,, and how,, humans,, underestimate,, their observations,, and their notions,, of attachement..
    Science, bird cams, and tags,, will never leap,, and that link,, ever..

  7. Joe Papp says:

    nice little write up. enjoyed reading it. thanks!

  8. Susan Dunsford says:

    Nice reading. I have a peanut wreath for jays and squirrels. The jays will come and off-load three or four peanuts letting them drop to the ground. Then will take a final peanut and fly off to eat it ignoring the ones on the ground…which the squirrels then come and eat. Can’t figure out this behavior. I have had peanut plants sprout in my raised beds.

    • Mary Jensen says:

      How did you make your peanut wreath? I have two Jays and a very fat squirrel living here and would love to provide a wreath. I have a hanging basket that my husband made for me and I load it up with roasted peanuts. It would be fun to see them picking at the wreath

  9. Kim Scott says:

    I just watched one blue jay regurgitate a milky fluid into another jay’s open mouth. They were were about 8 inches away from each other, perched on tree branches less than 20 feet away from me. A bit landed on the bird, which it immediately appeared to eat too. It is way too early for very young up North here. We are on the far of the yellow (summer) area of distribution map above, on the Alberta/BC border. Our blue jays are here year round, and we still have over a foot on snow. I am still looking for information on this feeding behaviour.

  10. quito says:

    I just watched a blue jay washing sunflower seeds from commercial bird food. I leave trays of water for the small birds to wash and drink from. The jays have started to drink from it now but today one brought a mouthful of S.F.Seeds and dropped five of them in the feeder intentionally and took a moutful of water then picked up a seed one at a time then dropped a few more in and repeated. Then took a larger gulp and lifted his head back and opened his croup and washed the seeds down whole.
    I have found no other references to this behavior…have you?

  11. quito says:

    re: jay washing seeds. please reply by email

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