North Pacific right whale
The Northeast Pacific subpopulation, which summers in the southeastern Bering Sea and Gulf of Alaska. A western subpopulation that summers in the Sea of Okhotsk between the Kuril Islands and Sakhalin Island.
The North Pacific right whale (Eubalaena japonica) is a very large, robust baleen whale species that is now extremely rare and endangered. The Northeast Pacific subpopulation, which summers in the southeastern Bering Sea and Gulf of Alaska, may have no more than 50 animals. A western subpopulation that summers in the Sea of Okhotsk between the Kuril Islands and Sakhalin Island appears to number in the low hundreds of animals. Prior to commercial whaling in the North Pacific (i.e. pre-1835) the populations in the North Pacific probably were over 20,000 animals. The taking of right whales in commercial whaling has been prohibited by one or more international treaties since 1935. Between 1962 and 1968, illegal Soviet whaling killed 529 right whales in the Bering Sea and Gulf of Alaska as well as 132 right whales in the Sea Okhotsk.
The International Union for the Conservation of Nature categorizes the species as "Endangered". It categorizes the Northeast Pacific subpopulation as "Critically Endangered". According to the Center for Biological Diversity, the North Pacific right whale is the most endangered whale on Earth.
North Pacific Right whales are very large and can reach from 15 to 18.3 m (49 to 60 ft) in length as adults, larger than the North Atlantic Right Whale.Typical body mass is from 50,000–80,000 kg (110,000–180,000 lb). There is one record of a 19.8 m (65 ft) whale. They are much larger than gray or humpback whales.
Like right whales in other oceans, North Pacific right whales feed primarily on copepods, mainly the species Calanus marshallae. They also have been reported off Japan and in the Gulf of Alaska feeding on copepods of the genus Neocalanus with a small quantity of euphausiid larvae, Euphausia pacifica.
Adults normally start reproducing when 5–10 years old and reach their full length after 20–30 years. In the smallest balaenopterid, the minke whale, 3 m (9.8 ft) calves are born after a 10-month pregnancy and weaning lasts until it has reached about 5–5.5 m (16.5–18 ft) after 6–7 months.Unusual for a baleen whale, female minkes (and humpbacks) can become pregnant immediately after giving birth; in most species, a 2– to 3-year calving period is the norm. In right whales, the calving interval is usually 3 years.
Like the other Eubalaena species, North Pacific Right Whales are known to interact with other cetacean species. Several observations of North Pacific Right Whales to interact with groups or solitary Humpback Whales have been recorded in both Eastern and Western North Pacific. A record of a pair of Gray Whales were seen showing signs of aggression towards a Right Whale and chasing it off California, 1998,while a sub-adult Right Whale was seen swimming in a group of critically endangered Western Gray Whales with social behaviors demonstrated in inshore water (Piltun Bay region) of Sakhalin's northeast coast in 2012.