sheathbill

noun

1. either of two white sea birds, Chionis alba or C. minor, of the colder parts of the Southern Hemisphere: so called from the horny sheath covering the base of the upper bill.

noun

1. either of two pigeon-like shore birds, Chionis alba or C. minor, of antarctic and subantarctic regions, constituting the family Chionididae: order Charadriiformes. They have a white plumage and a horny sheath at the base of the bill