Male and female pigeons are difficult to distinguish as both are similar in coloration. Female pigeons, though, have a tendency to hold their tail higher and waddle when walking, and are somewhat smaller in size. Despite gregarious traits, individuals have been known to live apart from any flock. Pigeons are monogamous and mate for life, but with the disappearance of a mate, they may choose another. Although breeding may occur in all seasons of the year, peak reproduction occurs in the spring and fall.
Male pigeons are more aggressive and strut.
In a mating display, males fluff up their neck ruff, drag their tail on the ground, and make loud, cooing noises. While the male selects the nest site, both sexes are involved in nest construction. Nests consist of twigs and grasses and are often located on building ledges and rafters or in eaves, steeples, and vents. Clutch size is generally one to two and the incubation period is 17-19 days. Newly-hatched pigeons or squabs are fed a substance called pigeon milk, which is produced inside the crop of both parents.