Dolphin Killer whales have the second largest brain mass of any animal on earth, next to the sperm whale. The brain to body mass ratio in some is second only to humans. Self-awareness is seen, by some, to be a sign of highly developed, abstract thinking. Self-awareness, though not well-defined scientifically, is believed to be the precursor to more advanced processes like meta-cognitive reasoning (thinking about thinking) that are typical of humans. Research in this field has suggested that cetaceans, among others, possess self-awareness. The most widely used test for self-awareness in animals is the mirror test in which a mirror
Bowhead whale organ provides a mechanism of cooling for the whale (which is normally protected from the cold Arctic waters by or more of fat). During physical exertion, the whale must cool itself to prevent hyperthermia (and ultimately brain damage). It is believed that this organ becomes engorged with blood, causing the whale to open its mouth to allow cold seawater to flow over the organ, thus cooling the blood. Bowhead whales are not social animals, typically travelling alone or in small pods of up to 6. They are able to dive and remain submerged underwater for up to an hour. The