Editing Cetacean surfacing behaviour (section)

=== Breaching and lunging === <!--'Breach' seems to link here, regardless of classification-->
<gallery widths="190" heights="180">
File:Anim1091 - Flickr - NOAA Photo Library.jpg|Humpback whale spinner-breaching
File:Dwarf sperm whale (NOAA Pitman).jpg|[[Dwarf sperm whale]] breaching
File:Killerwhales jumping.jpg|[[Orca]]s double-breaching off the south side of [[Unimak Island]], [[Alaska]]
File:Hector'sDolphinsCloudyBay 21Feb2012 AnjanetteBaker.tif|[[Hector's Dolphin]]s off [[Cloudy Bay]], New Zealand
</gallery>
[[File:Humpback juvenile breach sequence.jpg|right|thumb|[[Humpback whale]] breach sequence]]
A ''breach'' or a ''lunge'' is a leap out of the water, also known as cresting. The distinction between the two is fairly arbitrary: cetacean researcher [[Hal Whitehead]] defines a breach as any leap in which at least 40% of the animal's body clears the water, and a lunge as a leap with less than 40% clearance.<ref name="Hal">{{Citation|title=Publications List|author=Whitehead Lab|url=http://whitelab.biology.dal.ca/labpub.htm|access-date=2015-05-25}}</ref> Qualitatively, a breach is a genuine jump with an intent to clear the water, whereas a lunge is the result of a fast upward-sloping swim that has caused the whale to clear the surface of the water unintentionally. This latter "lunging" behaviour is often a result of feeding in [[rorqual]]s.<ref name="Ware2011">{{Citation|title=Shallow and deep lunge feeding of humpback whales in fjords of the West Antarctic Peninsula|first1=C.|last1=Ware|first2=A. S.|last2=Friedlaender|first3=D. P.|last3=Nowacek|year=2011|journal=Marine Mammal Science|volume=27|issue=3|pages=587–605|doi=10.1111/j.1748-7692.2010.00427.x|bibcode=2011MMamS..27..587W }}</ref> The right, humpback, and sperm whales are the most widely observed jumpers. However other [[baleen whale]]s such as [[Fin whale|fin]], [[Blue whale|blue]], [[Minke whale|minke]], [[Gray whale|gray]] and [[Sei whale|sei]] whales also breach. [[Oceanic dolphin]]s, including the [[orca]], are very common breachers and are in fact capable of lifting themselves completely out of the water very easily, although there is little distinction between this and [[#Porpoising|porpoising]]. Some non-cetacean marine creatures also exhibit breaching behavior, such as several shark species and rays of the genera ''[[Manta ray|Manta]]'' and ''[[Mobula]]''.<ref>{{Cite web|url=http://www.malbertphoto.com/mobulas1.html|title=The Flying Mobulas of the Sea of Cortez|author=Paul and Michael Albert|date=26 June 2005|url-status=dead|archive-url=https://web.archive.org/web/20130504035343/http://www.malbertphoto.com/mobulas1.html|archive-date=4 May 2013}}</ref>

Two techniques are used by cetaceans in order to breach. The first method, most common in sperm and humpback whales, is conducted by swimming vertically upwards from depth, and heading straight out of the water.<ref name="Dodo">{{citation|title=This is how whales break through the surface of the water|author=The Dodo|access-date=2015-05-25|url=https://www.thedodo.com/whales-breach-underwater-gifs-736758901.html|url-status=dead|archive-url=https://web.archive.org/web/20150525104940/https://www.thedodo.com/whales-breach-underwater-gifs-736758901.html|archive-date=2015-05-25}}</ref> The other more common method is to travel close to the surface and parallel to it, and then jerk upwards at full speed with as few as 3 tail strokes to perform a breach.<ref name="Dodo" /><ref name="CB">{{Citation|title=Breaching|publisher=Conscious Breath Adventures|url=http://consciousbreathadventures.com/breaching/|access-date=2015-05-25}}</ref> In all breaches the cetacean clears the water with the majority of its body at an acute angle, such as an average of 30° to the horizontal as recorded in sperm whales.<ref>{{citation|title=Sperm whales: social evolution in the ocean|author=Hal Whitehead|year=2003|publisher=[[University of Chicago Press]]|page=[https://archive.org/details/spermwhalessocia0000whit/page/179 179]|isbn=978-0-226-89517-8|url=https://archive.org/details/spermwhalessocia0000whit/page/179}}</ref> The whale then turns to land on its back or side, and less frequently may not turn but "belly flop" instead. In order to achieve 90% clearance, a humpback needs to leave the water at a speed of eight metres per second or {{convert|29|km/h}}. For a {{convert|36|MT|ST}} animal, this results in a [[momentum]] of 288 thousand [[newton second]]s. Despite its energetic cost, breaching is often carried out in series. The longest recorded sustained series was by a humpback near the [[West Indies]] totaling 130 leaps in less than 90 minutes.<ref>{{cite web|url=http://www.animalcorner.co.uk/marine/whales/whale_behaviour.html|title=Whale Behaviour|date=26 February 2015 |publisher=Animal Corner}}</ref> Repeated breaches tire the animal, so less of the body clears the water each time.<ref name="Whitehead2003">{{Citation |title=Sperm Whales: Social Evolution in the Ocean |first=Hal |last=Whitehead |page=181|isbn=978-0-226-89517-8|url=https://books.google.com/books?id=TKXdCli7nI0C&pg=PA181 |year=2003|publisher =University of Chicago Press|location=Chicago}}</ref>

Ultimately, the reasons for breaching are unknown; however, there is evidence to support a range of hypotheses. Whales are more likely to breach when they are in groups, suggesting that it is a non-verbal signal to other group members during social behaviour. Scientists have called this theory [[signalling theory|"honest signalling"]]. The immense cloud of bubbles and underwater disturbance following a breach cannot be faked; neighbours then know a breach has taken place. A single breach costs a whale only about 0.075% of its total daily energy intake, but a long series of breaches may add up to a significant energy expenditure.<ref name="Whitehead2003" /> A breach is therefore a sign that the animal is physically fit enough to afford energy for this acrobatic display, hence it could be used for ascertaining dominance, courting or warning of danger.<ref name="Dodo" /> It is also possible that the loud "smack" upon re-entering is useful for stunning or scaring prey, similar to [[#Lobtailing and slapping|lobtailing]]. As breaching is often seen in rough seas it is possible that a breach allows the whale to breathe in air that is not close to the surface and full of spray, or that they use breaching to communicate when the noise of the ocean would mask acoustic signals.<ref name="USCB">{{Citation|title=Why do whales and other sea mammals breach?|author=USCB ScienceLine|url=http://scienceline.ucsb.edu/getkey.php?key=682}}</ref> Another widely accepted possible reason is to dislodge parasites from the skin.<ref name="USCB" /> The behaviour may also be more simply a form of play.<ref name="USCB" />