Immature birds have brownish black bodies, black and gray bills, and dusky colored heads and tails.
White coloring begins to appear when the birds approach four years of age. Attract lifelong mates by calling, chasing and diving at one another. Nest is made of sticks and lined with grass, feathers, pine needles and moss. Females lay 1-3 eggs anytime from late October through early December. Eggs hatch after an incubation period of 35 days.