Editing Orca (section)

==Characteristics==
[[File:Typical killer whale markings.png|thumb|right|Different angle views of a typical female orca's appearance]]
Orcas are the largest extant members of the dolphin family. Males typically range from {{cvt|6|to|8|m}} long and weigh in excess of {{cvt|6|t}}. Females are smaller, generally ranging from {{cvt|5|to|7|m}} and weighing about {{cvt|3|to|4|t}}.{{sfn|Baird|2002|p=129}} Orcas may attain larger sizes as males have been recorded at {{cvt|9.8|m}} and females at {{cvt|8.5|m}}.<ref name="Heyning1988"/> Large males can reach a weight of over {{cvt|10|t}}.<ref>{{cite book |last1=Webber |first1=Marc A. |last2=Jefferson |first2=Thomas Allen |last3=Pitman |first3=Robert L. |title=Marine Mammals of the World: A Comprehensive Guide to Their Identification |date=28 July 2015 |publisher=Academic Press |isbn=978-0-12-409592-2 |page=189 |url=https://books.google.com/books?id=sc-cBAAAQBAJ |language=en}}</ref><ref>{{cite journal |last1=Anderson |first1=Robert |last2=Waayers |first2=Robyn |last3=Knight |first3=Andrew |title=Orca Behavior and Subsequent Aggression Associated with Oceanarium Confinement |journal=Animals |date=August 2016 |volume=6 |issue=8 |pages=49 |doi=10.3390/ani6080049 |doi-access=free |pmid=27548232 |pmc=4997274 |language=en |issn=2076-2615}}</ref> Calves at birth weigh about {{cvt|180|kg}} and are about {{cvt|2.4|m}} long.<ref>{{cite magazine|last=Olsen|first=Ken|date=2006|magazine=National Wildlife|volume=44|issue=6|pages= 22–30|title=Orcas on the edge|issn=0028-0402}}</ref><ref>{{cite magazine|last=Stewart|first=Doug|date=2001|magazine=National Wildlife|volume=39 |issue=1|pages=54–59|title=Tales of two orcas|issn=0028-0402}}</ref> The skeleton of the orca is typical for an oceanic dolphin, but more robust.<ref name="Heyning1988">{{cite journal | last1 = Heyning | first1 = J. E. | last2 = Dahlheim | first2 = M. E. | year = 1988 | title = ''Orcinus orca'' | url = http://www.science.smith.edu/msi/pdf/i0076-3519-304-01-0001.pdf | journal = Mammalian Species | issue = 304 | pages = 1–9 | doi = 10.2307/3504225 | url-status = dead | archive-url = https://web.archive.org/web/20120118134712/http://www.science.smith.edu/msi/pdf/i0076-3519-304-01-0001.pdf | archive-date = January 18, 2012 | df = mdy-all | jstor = 3504225 | s2cid = 253914153 }}</ref> They can also reach speeds of up to 56 km/h (35 mph)<ref>{{Cite web |title=Killer Whale (Orcinus orca) {{!}} U.S. Fish & Wildlife Service |url=https://www.fws.gov/species/killer-whale-orcinus-orca#:~:text=fastest,%2056%20km/h |access-date=2025-03-10 |website=www.fws.gov |language=en}}</ref>

With their distinctive pigmentation,<ref name="Heyning1988"/> adult orcas are rarely confused with any other species.{{sfn|Carwardine|2001|p=20}} When seen from a distance, juveniles can be confused with [[false killer whale]]s or [[Risso's dolphin]]s.<ref>{{cite web|url=http://wildwhales.org/other-species/ |title=Wild Whales|publisher=Vancouver Aquarium |access-date=March 23, 2012|url-status=dead|archive-url=https://web.archive.org/web/20120405040406/http://wildwhales.org/other-species/|archive-date=April 5, 2012}}</ref> The orca is mostly black but with sharply bordered white areas. The entire lower jaw is white and from here, the colouration stretches across the underside to the genital area; narrowing and expanding some, and extending into lateral flank patches close to the end. The tail fluke (fin) is also white on the underside, while the eyes have white oval-shaped patches behind and above them, and a grey or white "saddle patch" exists behind the dorsal fin and across the back.<ref name="Heyning1988"/><ref name=Perrin2/> Males and females also have different patterns of black and white skin in their genital areas.{{sfn|Ford|Ellis|Balcomb|2000|p=45}} In newborns, the white areas are yellow or orange coloured.<ref name="Heyning1988"/><ref name=Perrin2>{{cite book|editor-first1=William F.|editor-last1=Perrin|editor-first2=Bernd |editor-last2= Wursig|editor-first3=J. G. M. 'Hans' |editor-last3=Thewissen|title=Encyclopedia of Marine Mammals|year=2009|publisher=Academic Press|isbn=978-0-08-091993-5|last=Ford|first=John K. B. |contribution=Killer Whale|pages=550–556}}</ref> Antarctic orcas may have pale grey to nearly white backs.{{sfn|Carwardine|2001|p=20}} Some Antarctic orcas are brown and yellow due to [[diatoms]] in the water.<ref name="Pitman2003"/> Both [[albino]] and [[melanistic]] orcas have been documented.<ref name="Heyning1988"/>

[[File:Orca sexual dimorphism.png|thumb|right|Adult males' pectoral fins, dorsal fin, and flukes are larger than females'. Image shows sexual dimorphism between them.]]
Orca [[pectoral fin]]s are large and rounded, resembling paddles, with those of males significantly larger than those of females. [[Dorsal fin]]s also exhibit [[sexual dimorphism]], with those of males about {{cvt|1.8|m}} high, more than twice the size of the female's, with the male's fin more like an elongated [[isosceles triangle]], whereas the female's is more curved.<ref>[https://web.archive.org/web/20110721045535/http://www.acsonline.org/factpack/KillerWhale.htm Orca (Killer whale)]. American Cetacean Society. Retrieved January 2, 2009</ref> In the skull, adult males have longer lower jaws than females, as well as larger [[External occipital crest|occipital crest]]s.{{sfn|Heptner|Nasimovich|Bannikov|Hoffmann|1996|p=681}} The snout is blunt and lacks the beak of other species.<ref name="Heyning1988"/> The orca's teeth are very strong, and its jaws exert a powerful grip; the upper teeth fall into the gaps between the lower teeth when the mouth is closed. The firm middle and back teeth hold prey in place, while the front teeth are inclined slightly forward and outward to protect them from powerful jerking movements.{{sfn|Heptner|Nasimovich|Bannikov|Hoffmann|1996|p=683}}

Orcas have good eyesight above and below the water, excellent hearing, and a good sense of touch. They have exceptionally sophisticated [[Animal echolocation|echolocation]] abilities, detecting the location and characteristics of prey and other objects in the water by emitting clicks and listening for echoes,{{sfn|Carwardine|2001|pp=30–32}} as do other members of the dolphin family. The mean body temperature of the orca is {{cvt|36|to|38|C}}.<ref name="seaworld1">{{cite web|url=http://www.seaworld.org/animal-info/info-books/killer-whale/adaptations.htm |title=Killer Whales&nbsp;— Adaptations for an Aquatic Environment |publisher=Seaworld.org |access-date=September 14, 2013 |url-status=dead |archive-url=https://web.archive.org/web/20130904021401/http://www.seaworld.org/animal-info/info-books/killer-whale/adaptations.htm |archive-date=September 4, 2013 }}</ref><ref>N. W. Kasting, S. A. L. Adderly, T. Safford, K. G. Hewlett (1989). "Thermoregulation in Beluga (''Delphinapterus luecas'') and Killer (''Orcinus orca'') Whales"</ref> Like most marine mammals, orcas have a layer of insulating [[blubber]] ranging from {{cvt|7.6|to|10|cm}} thick beneath the skin.<ref name="seaworld1"/> The pulse is about 60 heartbeats per minute when the orca is at the surface, dropping to 30 beats/min when submerged.<ref name="Spencer, Gornall & Poulter (1967)">{{cite journal |last1=Spencer |first1=M. P. |last2=((Gornall 3rd)) |first2=T. A. |last3=Poulter |first3=T. C. |date=1967 |title=Respiratory and cardiac activity of killer whales |journal=Journal of Applied Physiology |volume=22 |issue=5 |pages=974–981 |doi=10.1152/jappl.1967.22.5.974|pmid=6025756 }}</ref>

An individual orca can often be identified from its dorsal fin and saddle patch. Variations such as nicks, scratches, and tears on the dorsal fin and the pattern of white or grey in the saddle patch are unique. Published directories contain identifying photographs and names for hundreds of North Pacific animals. Photographic identification has enabled the local population of orcas to be counted each year rather than estimated, and has enabled great insight into life cycles and social structures.{{sfn|Obee|Ellis|1992|pp=1–27}}