Severnaya Zemlya any traces of land to the north of the wide strait between the Kara Sea and the Laptev Sea that they navigated. The archipelago was not put on the map until the 1913–1915 Arctic Ocean Hydrographic Expedition of icebreakers "Taimyr" and "Vaigach". The chief organiser and first captain of the Vaygach was officer Aleksandr Vasiliyevich Kolchak of the Imperial Russian Navy. The expedition was privately financed and was launched in 1910, being led by Boris Vilkitsky on behalf of the Russian Hydrographic Service. This venture accomplished its goal of exploring the uncharted areas of the continental side of the Northern
Severnaya Zemlya to a survey of prior observations by De Korte, Volkov, and Gavrilo, thirty-two bird species have been observed on Severnaya Zemlya, 17 of which are known to breed on the islands. Eight species are widespread across the archipelago: five of which are colonial seabirds: little auk ("Alle alle"), black-legged kittiwake ("Rissa tridactyla"), black guillemot ("Cepphus grylle"), ivory gull ("Pagophila eburnea"), and glaucous gull ("Larus hyperboreus"); and three species of tundra bird: the snow bunting ("Plectrophenax nivalis"), purple sandpiper ("Calidris maritima"), and brent goose ("Branta bernicla"). The most common mammal on Severnaya Zemlya is the collared lemming ("Dicrostonyx torquatus"), also known