Black skimmer  (Rynchops niger)

The largest of the three skimmer species (4), the black skimmer is an unmistakable bird, best known for its remarkable beak (2) (5). As in all skimmers, this unusual structure is long and deep, with flattened, blade-like mandibles, and the lower mandible is longer than the upper (2) (3) (5) (6). The beak of the black skimmer is bright red at the base and black at the tip, and the upper mandible is slightly downcurved (2) (3) (5). Together with the bright red legs, it provides a colourful contrast to the white underparts and sides of the head, and the black upperparts and cap (3) (5) (6). The eye is somewhat invisible within the black feathering on the head (5), and the body appears unusually front-heavy due to the long beak and large head (2). The wings are long, narrow and pointed (5) (7), and the tail, which is white with a dark central streak, is slightly forked (2) (3) (5). The legs are short, with webbed toes (5) (7).

The male black skimmer is significantly larger than the female, with a longer beak, but is similar in colouration (2) (4) (5) (8). Non-breeding adults have a white collar on the neck, and somewhat browner upperparts, while immature birds are browner and more mottled than adults, with a duller beak (2) (3) (5). Three subspecies of black skimmer are recognised. Rynchops niger cinerascens and Rynchops niger intercedens are larger than Rynchops niger niger, and vary in the colour and markings on the wing linings and tail (2) (5) (6). The black skimmer has a relaxed and buoyant flight (2) (3) (5), and calls with an unusual, dog-like nasal “yip” (3) (5) (7).