Black Sea–Caspian Steppe Black Sea–Caspian Steppe The Black Sea-Caspian Steppe is an informal name for that part of the Eurasian Steppe that extends south between the Black and Caspian Seas. It is usually treated as part of the Pontic-Caspian steppe which includes the area north of the Black and Caspian Seas, but there is some reason to treat it as a distinct place. Its natural boundaries are the Sea of Azov and Black Sea on the west, the Caucasus Mountains on the south and the Caspian Sea on the east. Its northern boundary may be taken as the triangle formed by the lower
Caspian tern Caspian tern The Caspian tern ("Hydroprogne caspia") is a species of tern, with a subcosmopolitan but scattered distribution. Despite its extensive range, it is monotypic of its genus, and has no accepted subspecies. The genus name is from Ancient Greek "hudros", "water", and Latin "progne", "swallow". The specific "caspia" is from Latin and, like the English name, refers to the Caspian Sea. It is the world's largest tern with a length of , a wingspan of and a weight of . Adult birds have black legs, and a long thick red-orange bill with a small black tip. They have a