Toothed whale brain size with the expected brain size based on such allometric analysis provides an encephalisation quotient that can be used as another indication of animal intelligence. Sperm whales have the largest brain mass of any animal on earth, averaging and in mature males, in comparison to the average human brain which averages in mature males. The brain to body mass ratio in some odontocetes, such as belugas and narwhals, is second only to humans. Dolphins are known to engage in complex play behaviour, which includes such things as producing stable underwater toroidal air-core vortex rings or "bubble rings". Two main
Subsistence hunting of the bowhead whale say that one cannot live without the other. According to the Iñupiat, the whale is the center of their diet, culture, and spirit. This makes them dependent on the complex system of sharing and celebrating the whale, and leads them to pray to any killed bowhead whale in thanks for the life it has given to them. For the Iñupiat, subsistence hunting and fishing are important and viable economic strategies, which provide food and raw materials for the whole group. When hunters bring whales back to the community, about 65–70 people drag the whale onto the ice, where they work