<P> These birds forage on the ground or in vegetation; they also fly down from a perch to capture food . While foraging, they frequently spread their wings in a peculiar two - step motion to display the white patches . There is disagreement among ornithologists over the purpose of this behavior, with hypotheses ranging from deceleration to intimidation of predators or prey . </P> <P> Both the male and female of the species reach sexual maturity after 1 year of life . The breeding season occurs in the spring and early summer . The males arrive before the beginning of the season to establish their territories . The males use a series of courtship displays to attract the females to their sites . They run around the area either to showcase their territory to the females or to pursue the females . The males also engage in flight to showcase their wings . They sing and call as they perform all of these displays . The species can remain monogamous for many years, but incidents of polygyny and bigamy have been reported to occur during the bird's lifetime . </P> <P> The northern mockingbird pairs hatch about 2 to 4 broods a year . In one breeding season, the northern mockingbird lays an average of 4 eggs . They hatch after about 11 to 14 days of incubation . After about 10 to 15 days of life, the offspring become independent . </P> <P> Both the male and female are involved in the nest building . The male does most of the work, while the female perches on the shrub or tree where the nest is being built to watch for predators . The nest is built approximately three to ten feet above the ground . The outer part of the nest is composed of twigs, while the inner part is lined with grasses, dead leaves, moss, or artificial fibers . The eggs are a light blue or greenish color and speckled with dots . The female lays three to five eggs, and she incubates them for nearly two weeks . Once the eggs are hatched, both the male and female will feed the chicks . </P>

How many days for mockingbird eggs to hatch