Editing Whale (section)

===Intelligence===
{{Main|Cetacean intelligence}}
{{See also|Cetacean surfacing behaviour}}

Whales are known to teach, learn, cooperate, scheme, and grieve.{{sfn|Siebert|2009}} The neocortex of many species of whale is home to elongated [[spindle neurons]] that, prior to 2007, were known only in hominids.{{sfn|Watson|2006|pp=1107–1112}} In humans, these cells are involved in social conduct, emotions, judgement, and theory of mind. Whale spindle neurons are found in areas of the brain that are homologous to where they are found in humans, suggesting that they perform a similar function.{{sfn|Hof|2007|pp=1–31}}

[[File:Whales Bubble Net Feeding-edit1.jpg|thumb|Bubble net feeding]]

[[Brain size]] was previously considered a major indicator of the intelligence of an animal. Since most of the brain is used for maintaining bodily functions, greater ratios of brain-to-body mass may increase the amount of brain mass available for more complex cognitive tasks. [[Allometric]] analysis indicates that mammalian brain size scales at approximately the {{frac|2|3}} or {{frac|3|4}} exponent of the body mass. Comparison of a particular animal's brain size with the expected brain size based on such allometric analysis provides an [[encephalization quotient|encephalisation quotient]] that can be used as another indication of animal intelligence. [[Sperm whale]]s have the largest brain mass of any animal on Earth, averaging {{convert|8000|cm3|in3}} and {{convert|7.8|kg|lbs}} in mature males, in comparison to the average human brain which averages {{convert|1450|cm3|in3}} in mature males.{{sfn|NOAA Fisheries|2013}} The [[brain-to-body mass ratio]] in some odontocetes, such as belugas and narwhals, is second only to humans.{{sfn|Mind Matters|2008}}

Small whales are known to engage in complex play behaviour, which includes such things as producing stable underwater [[toroid]]al air-core [[vortex]] rings or "[[bubble ring]]s". There are two main methods of bubble ring production: rapid puffing of a burst of air into the water and allowing it to rise to the surface, forming a ring, or swimming repeatedly in a circle and then stopping to inject air into the [[Helix|helical]] vortex currents thus formed. They also appear to enjoy biting the vortex-rings, so that they burst into many separate bubbles and then rise quickly to the surface.{{sfn|Deep Ocean}} Some believe this is a means of communication.{{sfn|Griffin|2015}} Whales are also known to produce bubble-nets for the purpose of foraging.{{sfn|Wiley et al.|2011|pp=575–602}}

Larger whales are also thought, to some degree, to engage in play. The [[southern right whale]], for example, elevates their tail fluke above the water, remaining in the same position for a considerable amount of time. This is known as "sailing". It appears to be a form of play and is most commonly seen off the coast of [[Argentina]] and [[South Africa]]. [[Humpback whale]]s, among others, are also known to display this behaviour.{{sfn|Leighton et al.|2007|pp=17–21}}

{{anchor|Reproduction}}