Sheathbills: Chionidae

Physical characteristics: Black-faced sheathbills range from 15 to 16.1 inches in length (38 to 41 centimeters) and from 19 to 32 ounces (540 to 900 grams) in weight. They have a wingspan, distance from wingtip to wingtip, of 29.1 to 31.1 inches (74 to 79 centimeters). They have black bills, black sheaths, and black carbuncles on their faces. The feathers are all white.

Geographic range: Black-faced sheathbills are found on a handful of subantarctic islands in the Indian Ocean. These include Marion, Prince Edward, Crozet, Kerguelen, Heard, and McDonald Islands.

Habitat: Black-faced sheathbills are found in the colonies of penguins and other seabirds, typically on rocky or sandy beaches. They may also occupy meadows and bogs close to shore.

Diet: Black-faced sheathbills eat the eggs, chicks, and excrement of seabirds. They also steal food that seabird parents bring back for their chicks. Black-faced sheathbills may also eat dead seal pups and seal milk. If these aren't available, they eat algae and invertebrates.

Behavior and reproduction: Black-faced sheathbills do not migrate, but remain in one place throughout the year. Pairs defend their territories from other sheathbills all year round. Black-faced sheathbills are most often associated with colonies of king penguins. Black-faced sheathbills are monogamous, with a single male breeding with a single female. The female lays two to three eggs in December or January, with breeding at the same time as that of the seabirds among which they live. Chicks hatch after twenty-seven to thirty-three days.

Black-faced sheathbills and people: Black-faced sheathbills have little interaction with people. They sometimes eat food scraps left by humans near research stations or eat human excrement.

Conservation status: Black-faced sheathbills are not considered threatened. ∎