Gray jays reside in coniferous and deciduous forests, specifically, in spruce (Picea), aspen (Populus), fir (Abies), and sugar maple (Acer saccharum)-dominated forests. Gray jays are dependent on these trees for safety as well as reproduction. Gray jays also thrive around permanent waterbodies, from small ponds to the Great Lakes. In the summer, gray jays typically live at elevations from 2,618 m to 3,048 m. In winter, individuals live at lower elevations in the eastern and western United States. Gray jays are not found in elevations below 600 m. At their lowest elevations, gray jays are found in spruce bogs. (BirdLife International, 2012; Strickland and Ouellet, 2011; Waite, 1991)
Gray jays are birds that weigh between 62-82 grams. Sexes are similar in size and color, which consists of dark and light gray, black, tan, and white. This short-billed species grows to adults that have black legs and white auriculars, which are the feathers located in the ‘cheek’ area that cover the ear canal. This species resembles common blue jays (Cyanocitta cristata), but gray jays are smaller and darker.
Their adult wingspan averages 45 centimeters. From their head to the tip of their tail, on average, their length is 29.21 centimeters. If these birds are located towards the eastern United States, their color will be slightly paler than birds from the Rocky Mountains.
Gray jay’s breast (ventral) feathers are short, and plentiful. In comparison, their dorsal feathers are very fine towards their heads and smooth on their wings. The smooth texture of their wings allows flight with less energy investment.
The hatchling’s first molt is completed between April and May and takes two weeks to complete. Although adults in this species are tri-colored, as young they are uniformly dark gray, almost black. Their coloring will resemble that of adults by May to August. Their ventral feathers turn to a lighter brown-cream color and their dorsal feathers turn a dusty gray color. (BirdLife International, 2012; Strickland and Ouellet, 2011; Waite, 1192)
Gray jays are monogamous birds that do not typically separate until their mate dies or disappears. After the loss of their mate, both the males and females will find another life-long partner. Few birds under various studies have ‘divorced’ after single breeding periods. Newly paired birds can join together during any part of the year, regardless of season. They have one breeding season that lasts from late February to early May.
Male-female courtship feedings occur during initial meetings, about 14 days before the first egg is laid. Mating is usually initiated by females through tail shaking motions, which is then mimicked by the males. Males also emit ‘whisper’ songs, which are soft whistles, to attract females. (BirdLife International, 2012; Ibarzabal, et al., 2004; Waite, 1192)
Males choose the site of the nests, and take the initial steps in construction. Nests are located at high elevations, are 10-15 cm tall, with an outer rim diameter of 14-16 cm. The initial building of the nest begins as early as February, three to four weeks before the first egg is laid by the females. Even though the males begin the construction on the nest, females are also very active in the preparation for new young by helping gather building materials, along with solely finishing the soft matting on the surface of the nest. This soft matting is composed of various hair from white-tailed deer (Odocoileus virginianus) and snowshoe hares (Lepus americanus). This hair bed creates an insulated environment that will protect the young from possible harsh climates. Females are found sitting on an empty nest for days before laying the first egg.
The eggs are laid, one per day, between the months of late February to March. This allows the young to avoid starvation, to develop skills, and to steadily adapt to winter climates through their first summer. In a breeding season, females will lay 2-4 green-gray eggs. Incubation periods for a single clutch typically are 18-19 days. Females begin the incubation period when the first egg is laid, and continue until all eggs are hatched. At the seven-day mark, the eggs weigh 5-6 grams.
At hatching, it will take between four and nine hours for the entire clutch to hatch. Female birds will assist their young with hatching by eating pieces of the eggshells. The chicks will weigh between 4.5-7 grams, with beak lengths (nostril to tip) between 3.0 and 4.0 millimeters.
Immediately after hatching, downy feathers cover the birds’ bodies. During the first two weeks after hatching, the new birds will gain 40 grams gradually. The down that covers their bodies turns to gray-purple feathers on day four of life. Although the hatchlings now have feathers, they still cannot fly. Their flight feathers begin to appear on day nine after hatching. The new birds begin to leave the nest around 17-23 days of age, walking on branches only a few days before. Young are independent between days 55 and 66. After leaving the nest, they will stay in their parents’ territory until they find a mate for themselves. The age that males and females reach sexual maturity is 1-2 years. (BirdLife International, 2012; Lehner and Farley, 1990; Waite, 1192; Walter, 1961)
Before hatching, both male and female mates gather materials to make insulated nests in order to keep their young warm in temperatures that can reach -34°C. Also in preparation for their young, both the males and females collect and store food throughout the year for winter. When the females are incubating the eggs, it is the males’ job to bring females food. Approximately 18-19 days after laying the eggs, females will begin breaking the egg shells to help the young break out of the eggs. Females will also clear any liquid out of the eggs so that the hatchlings do not inhale any fluid into their lungs.
After the eggs hatch, males bring food back to the nest for the females, who then create a brown paste-like food that eventually is fed to the hatchlings. The male parents will try to feed the young, but females soon take over to avoid any feeding by males. Both parents will take care of the nest after the young have hatched by cleaning out fecal sacs, along with jabbing at the nest with their beaks to loosen twigs and branches. This process helps to accommodate the growing birds.
While the females keep the hatchlings warm, males protect the nest by warding off predators with pecking. If a predator approaches the nest, the female birds will also protect the hatchlings to the best of their ability.
During the fledgling stage of life, both parents are significantly less involved, and education from parents is virtually non-existent. (BirdLife International, 2012; Ibarzabal, et al., 2004; Sechley, et al., 2014; Waite, 1192; Waite, 1991)
According to records on North American birds, gray jays live to be a maximum age of 19.2 years (wild). Juveniles, in their fledgling stage, have a 52% mortality rate per year in their natal territory. When forced out of their natal territory, in early June, juvenile gray jays have an 85% mortality rate per year. Upon reaching adulthood, the mortality rate significantly decreases to about 20% per year, due to their capability to protect themselves. Adults are more likely to die during the months of May through October than in winter months. No information has been recorded about gray jays’ mortality in captivity. (BirdLife International, 2012; Clapp, et al., 1983)
Gray jays hunt for food on the ground, and sleep in trees. They spend 95% of their day hunting and storing food. They catch their prey by walking on the ground at a fast pace. They can also forage by walking, flying, and running. On the forest floor, gray jays also spend much time sunbathing to stay warm during cold winters.
During the other 5% of the day, if they are not breeding, their time is spent in the trees like spruce (Picea) and balsam fir (Abies balsamea). Gray jays sleep closer to the trunk of the tree, and tuck their heads under their wings to stay warm. Gray jays are considered diurnal because they are active during the day and sleep at night.
Before mating, gray jays will live with other non-mating gray jays. Upon finding a mate, the pair will rarely part, and will push other gray jays out of their territory. This territoriality is to reduce competition for food. Food scarcity is most common at the start of winter, when grays jays are finding mates. Gray jays do not migrate to find mates and find their mates in their parent’s territory. The only time gray jays migrate is from moving from the outside of the forest to the inside during winter months. They do this because the center of the forest provides a barrier of trees from the cold climates. There have been few records of them migrating altitudinally, as well.
When displaying territorial behavior, gray jays lower their heads and run at other birds, like blue jays (Cyanocitta cristata). Gray jays also will threaten their own mates. The reasoning behind this is to force the other mate to give them food. (BirdLife International, 2012; Ibarzabal, et al., 2004; Sechley, et al., 2014; Waite, 1192; Waite, 2001; Walter, 1980; BirdLife International, 2012; Ibarzabal, et al., 2004; Sechley, et al., 2014; Strickland and Ouellet, 2011; Waite, 1192; Waite, 2001; Walter, 1980)
Gray jays in Canada have reported territories of 27 to 137.5 hectares. Strickland and Ouellet (2011) reported territories may be smaller (15.8 - 23.2 ha reported) if food is artificially supplemented. This number corresponded to about half of their typical territory in that region. (Strickland and Ouellet, 2011)
Communication by gray jays varies widely, and can signal warnings of danger or be used for mate attraction. Adult communications include screaming (high pitched, long tones) when the bird is in danger, and chatter (short tones) which is used around terrestrial predators. They also use alarm whistles around aerial predators, and social notes, which are two-parted whistles used to find a mate. The sounds that the gray jay makes varies between soft and loud chirps dependent on the situation. They also snap their bills around intruders to the nest and their territory.
Gray jays' vision is sufficient to spot food in the winter months, when food is scarce. When gray jays spot their food, they swoop down and grab it with their beaks. If the food is over one quarter of their body weight, they will transfer it from their beaks to their feet in order to fly. This motion uses their sense of balance when flying. Gray jays' sense of smell is fairly weak.
A trait that gray jays are known for is their mimicry. They are known to mimic owls, hawks, crows, and blue jays (Cyanocitta cristata). The mimicry adaptation is to intimidate potential predators by sounding like a predator themselves.
As nestlings, this species makes a distinct, high-pitched “chep” noise as a begging call. This noise changes by day five post-hatching, when the pitch changes to more hoarse and adult-like. By two weeks after hatching, the bird has fully developed louder adult calls. (BirdLife International, 2012; Lehner and Farley, 1990; Sieving and Wilson, 1999; Walter, 1980)
Gray jays are omnivores, foraging on berries, arthropods, worms, carrion, nestling birds, eggs, and some small mammals (including shrews, voles, and juvenile bats). They will snatch flying insects and even tear apart wasp’s nests. Gray jays eat small salamanders and toads, venturing into shallow water to forage. They also consume fungi. They've been known to use bird feeders provided by humans. They search for their food by perching on tree stumps and branches; when they have spotted their prey, they will swoop down and grab the item.
In preparation for winter, gray jays will practice caching behavior in August and September. This caching behavior consists of gray jays encasing their food in their sticky saliva and sticking the bundle to tree branches to preserve it during the winter months. Because gray jays consume little to no food in the winter, they use as little energy as possible. Reports of individuals caching >1000 items in a day are not uncommon. If they are unable to store enough food before winter, they will move to a slightly warmer location, which is towards the interior of the forest, where they are provided with more shelter from trees. Based on an average weight of 75 g, the average need for calories per day is 47 kcals for gray jays in Alaska. Gray jays in warmer climates or during warmer seasons need more calories per day. Their water supply is rarely limiting, drinking water from lakes in the summer, and getting water from snow in harsh winters. (BirdLife International, 2012; Lehner and Farley, 1990; Strickland and Ouellet, 2011)
Known predators of hatchling gray jays are red squirrels (Tamiasciurus hudsonicus) and broad-winged hawks (Buteo platypterus). Adult gray jay predators are northern goshawks (Accipiter gentilis), spotted owls (Strix occidentalis), peregrine falcons (Falco peregrinus), merlins (Falco columbarius), and red-tailed hawks (Buteo jamaicensis).
Adaptions found in gray jays are contoured feathers on their heads that make them appear larger than they really are. When confronted by a predator, their contour feathers stand up. Male gray jays also use their beaks to attack predators by pulling on the attackers’ feathers or fur. They also intimidate their attacker by hopping around them in circles while displaying their contour feathers, occasionally hopping towards them in a threatening motion.
Along with physical adaptations, gray jays also emit warning signals to one another. A loud whistle (long, soft tone) is given when an aerial predator is located, resulting in more cautious behavior by gray jays. When a predator is terrestrial, very loud chatter sounds (short, loud chirps) are emitted by gray jays to threaten the predator. They've also been known to mimic the calls of some predators as an intimidation technique.
Gray jays have also developed a defense mechanism by mobbing large predators. This mobbing consists of very loud screeching (high pitched chirps) while multiple male gray jays fly directly at the approaching predator. This behavior is directed towards harassment of the predator, and also functions in distracting the predators from harming young. This technique typically is used during early spring when young have just hatched and are incapable of defending themselves. This defense mechanism is commonly used on broad-winged hawks (Buteo platypterus), because this species is known for attacking and eating young gray jays.
Another predator adaption by gray jays is their color. Gray jays are light gray to charcoal gray and white, which allows them to blend in with bare trees and snow during the winter months. (BirdLife International, 2012; Lehner and Farley, 1990; Waite and Field, 2000; Waite, 1990)
Gray jays are hosts for parasites of protozoans (Leucocytozoon, Trypanosoma, Haemoproteus, Plasmodium), hippoboscid flies (Ornithomya bequarti) and one species of louse (Machaerilaemus cyanocittae).
On a negative note, Stickland and Oullet (2011) state that gray jays may be the the most significant species that spreads eastern dwarf mistletoe (Arceuthobium pusillum). This plant parasitizes black spruce Picea mariana and can be detrimental to spruce health. Therefore, their role as a seed disperser is painted in a negative light. (BirdLife International, 2012; Strickland and Ouellet, 2011)
A positive economic impact of gray jays is recreational and educational bird watching. Bird watching trips include travel, photography, and further study, and this industry is one of the fastest growing industries in North America. In Canada alone, at least 13.1% of the population took specialized trips to birdwatch. Bird watching expenditures are estimated to generate greater than 20 billion dollars each year. (Hvenegaard, et al., 1989)
There are no known negative economic effects of gray jays on humans.
The IUCN Red List classifies gray jays as a species of "Least Concern." Due to their population size, gray jays have no special status on the US Federal List, CITES, or the State of Michigan List. Gray jays are protected under the Migratory Bird Treaty Act, which means it is illegal for anyone to take, posses, import, export, transport, sell, purchase, barter, any bird protected.
Threats on gray jays include a warming climate, which will cause a significant shift in boreal forests. This shift will require gray jays to move their range northward. In addition to this threat, traps set to catch other animals are killing gray jays. In a 1950s study in which traps were set for furbearers, 292 gray jays were killed. However, a change in bait the second year of the study decreased mortality by >90%.
Breann Mullen (author), Radford University, Alex Atwood (editor), Radford University, Marisa Dameron (editor), Radford University, Karen Powers (editor), Radford University, Tanya Dewey (editor), University of Michigan-Ann Arbor.
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.
uses sound to communicate
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.
Referring to an animal that lives in trees; tree-climbing.
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.
a wetland area rich in accumulated plant material and with acidic soils surrounding a body of open water. Bogs have a flora dominated by sedges, heaths, and sphagnum.
an animal that mainly eats meat
flesh of dead animals.
uses smells or other chemicals to communicate
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.
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.
parental care is carried out by females
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
an animal that mainly eats fruit
An animal that eats mainly plants or parts of plants.
An animal that eats mainly insects or spiders.
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).
parental care is carried out by males
imitates a communication signal or appearance of another kind of organism
Having one mate at a time.
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
an animal that mainly eats all kinds of things, including plants and animals
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
an animal that mainly eats dead animals
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
associates with others of its species; forms social groups.
places a food item in a special place to be eaten later. Also called "hoarding"
uses touch to communicate
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).
uses sight to communicate
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