Whose funny valentine? - courtship behavior of the frigate-bird

National Wildlife, Feb-March, 1995 by Tui De Roy

When it comes to courtship, the male magnificent frigatebird gets all puffy

Come late winter, the male frigatebird's fancy turns to courtship in a flamboyant way. From his coastal perch in a low bush or tree, he inflates his red throat pouch, or gular sac, until it resembles a large red balloon. Then he turns it skyward to attract females hovering overhead, spreads and shakes his wings and makes a whinnying sound to complete the valentine show.

The largest of the five frigatebird species is the magnificent frigatebird shown here. With a wingspread aS wide as 8 feet, the 3-pound creature has the greatest wing area in proportion to its weight of any bird on Earth. As a result, it is a powerful acrobatic flier, adept at both bursts of high speed and idle gliding.

Frigatebirds are named in honor of their piratical behavior, after the eighteenth-century seafaring war vessels called frigates. Soaring majestically through the sky, a frigatebird will abruptly swoop down and harass another seabird into giving up its catch, then plunge to scoop up the fish or squid before it hits the water. However, a frigatebird does not depend entirely on thievery. It catches most of its food by snatching flyingfish from the air and by skimming the ocean surface to catch other prey.

Because their plumage is not waterproof, frigatebirds rarely alight on the water around the coastal tropical islands of the western Atlantic and the Pacific where they breed. In the United States, the birds range in the Florida Keys, on the coast of Southern California and occasionally along the Gulf Coast. A slightly smaller species, the great frigate, nests in the Hawaiian Islands.

After the male's display attracts a mate, the pair builds a nest in a coastal bush or tree. There, the female, which nests only once every other year, lays a single white egg. The resulting chick remains dependent on its mother for food for nearly two years. The male, meanwhile, has long since moved on to new horizons, hoping to attract another mate with his valentine performance.