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
Bowhead whale whales" were confirmed to be from bowhead whales. The bowhead whale has a large, robust, dark-coloured body and a white chin/lower jaw. The whale has a massive triangular skull, which it uses to break through the Arctic ice to breathe. Inuit hunters have reported bowheads surfacing through of ice. The bowhead also has a strongly bowed lower jaw and a narrow upper jaw. Its baleen is the longest of that of any whale, at , and is used to strain tiny prey from the water. The bowhead whale has paired blowholes, at the highest point of the head, which can