Skimmers are Tern-like birds having a very strangely developed bill. The lower mandible is much longer than the upper and very thin, the upper edge being as sharp as the lower. The lower mandible is rounded at the end while the upper is more pointed. Young Skimmers are said to have both mandibles of the same length, the abnormal development not appearing until after flight. Skimmers are very graceful birds, and, as implied by their name, they skim over the surface of the water, rising and falling with the waves, and are said to pick up their food by dropping the lower mandible below the surface, its thin edge cutting the water like a knife. There are four species of Skimmers, only one of which is found in North America.

80. Black Skimmer. Rynchops nigra.

Range.--The South Atlantic and Gulf Coasts, breeding from New Jersey southward. The Black Skimmer is about eighteen inches in length, and besides the remarkable bill is a bird of striking plumage; the forehead, ends of the secondaries, tail feathers and under parts are white; the rest of the plumage is black and the basal half of the bill is crimson. Skimmers nest in large communities, the same as do the Terns, laying their eggs in hollows in the sand. They are partially nocturnal in their habits and their hoarse barking cries may be heard after the shadows of night have enveloped the earth. Fishermen call them by the names of "Cut-water" and "Sea Dog." The nesting season commences in May and continues through June and July. They lay from three to five eggs, having a creamy or yellowish buff ground, blotched with black, chestnut and lilac. Size 1.75 × 1.30. Data.--Cobb's Is., Va., June 8, 1894. Three eggs laid in a hollow on the beach. No nest.