Blue Jay - Reproduction

Reproduction

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 (9.8 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.

Blue Jays are not very picky about nesting locations. If no better place is available - e.g. in a heavily deforested area - they will even use places like the large mailboxes typical of the rural United States. 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.

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 17–21 days after hatching.

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. Blue jays have been recorded to live for more than 26 years in captivity and one wild jay was found to have been around 17 and a half years old. A more common lifespan for wild birds that survive to adulthood is around 7 years. Beyond predation and the occasional collision with man-made objects, a common cause of mortality in recent decades has been the West Nile Virus, which corvids as a whole seem especially subceptible to. However, despite several major local declines, overall Blue Jays have not seemed to have been depleted by the disease.