There are three species of Skimmer birds, all in the family Rynchopidae; they are related to the sea gulls, terns and puffins. The African Skimmer is Rynchops flavirostris, the Indian Skimmer in Asia is Rynchops albisollis, and the Black Skimmer is Rynchops niger. The Black Skimmer inhabits most of South America, where it is found in three subspecies. One of these, R. n. niger, extends up into North America as far as the southern coasts including Florida, where it can be found year-round along both the Atlantic and Gulf Coasts.
The Black Skimmer is a strikingly handsome bird. About the size of a Crow, they are boldly patterned with black on top and white underneath, with a long conspicuous bill that is red or orange at the base and black at the tip. During the breeding season the back of the neck is solid black; it is whitish for the rest of the year. The wings are very long, and are black above and white below with a narrow white band running along the rear edge. The legs are red in color, and look absurdly short for such a large bird. Males are a bit bigger than the females.
In Florida, Skimmers are most often seen in saltwater bays and estuaries, though they sometimes venture inland and are occasionally seen at rivers and lakes. They are gregarious birds and hang around in large flocks, spending most of their day lounging on the sand, often in the company of terns and gulls. They seem to be a bit skittish, and it’s not unusual for the entire flock to take off in one chattering mass, for no apparent reason, fly in a big circle, and then land back at the same spot.
If you look closely at the bill, you will notice something odd about it: the lower half of the bill is very much longer than the upper half. This unique arrangement is an adaptation to the Skimmer’s odd method of catching food. When hunting, the Skimmer will glide along at the water surface with its mouth open and the tip of the lower bill submerged in the water. At it flies along, the bird’s submerged bill bumps into fish or shrimp, and instantly snaps it up. Although the birds have binocular vision and can see where they are aiming their bills, they depend mostly on their sense of touch to detect food, and often do most of their hunting at night. (Another unique adaptation is the bird’s vertical eye slits, like a cat, which give it better night vision.)
During nesting season, Skimmers scratch out a simple scrape in the sand and lay five or six mottled eggs that look like rocks. Both parents take turns incubating, and the flock acts together to mob and drive off potential egg predators such as gulls or raccoons. In some areas where the beaches have been developed, the Skimmers have taken to laying their eggs on nearby flat gravel roofs.
The young birds are a mottled brownish color, which helps camouflage them against predators while the adults are away fishing. The parents also use their long wings to shade the hatchlings from the sun. When hatched, the youngsters have normal equal-sized bills, but as the birds grow, the lower bill becomes elongated.
Although the Black Skimmer has a wide range in Florida and is present in large numbers, the population has been noticeably declining. This seems to be due to loss of habitat areas, human disturbance of breeding beaches, and predation on the eggs and hatchlings by domestic dogs. The state of Florida considers the Black Skimmer to be a Species of Special Concern.