The length of males is up to 21 m(15 m average), females – 12 m. Males weigh up to 58 tons (35 tons average). Newborns are 4 m long and weigh up to 1 ton.
It lives in almost all seas except for the circumpolar ones. The sperm whale is considered to be the most widespread species on Earth after humans and killer whales.
In the waters of the Commander Islands the sperm whale rests on the shelf edge. Photograph by Eugene Mamaev
The main part of their ration make up the cephalopods (squids), to a lesser extent, fish. While feeding they can dive to depths of 3200 m, but usually from 400 to 800 m. Duration of their immersion lasts for over an hour, normally up to 45 minutes. After the emersion they stay on the surface for 10 to 15 minutes. Life expectancy is up to 70 years or more. If you see it in the sea you can easily distinguish it from other species thanks to a lush fountain, directed at an angle to the horizon. During the immersion the sperm whale raises its tail high.
During the period of active whaling it was one of the main objects of prey. Migratory paths of sperm whales are poorly investigated. It is known, that males may remain in the high latitudes for several years before coming back to the southern waters for breeding.
The world population is about 360 000 individuals.
The species is written down in the IUCN Red List.
It was first noticed in the fauna of the Commander Islands by Leonhard Stejneger due to a beached animal in the late 19th century.
In the waters of the Commander Islands the sperm whale is a common species and presents all year round, but their number significantly increases in spring and reaches its peak in August-September. This is the best time to observe them. Mainly adult males spend their summer here (females with cubs also occasionally appear in these waters). They are registered on nearly the entire perimeter of the Commander Islands, but the largest concentrations are observed in the northern extremity of Bering Island and along the eastern shelf edge near the southern part of Medny Island at depths of 400 to 1000 m. The number of sperm whales off the coast of the Commander Islands is not known exactly, but probably within 100 or more individuals. Concentrations of up to 9 animals at once have been observed. Migrations of sperm whales off the Commander Islands’ coast have not been studied.
