Editing Dolphin (section)

===Reproduction and sexuality{{anchor|Reproductive_system}}===
{{See also|Bottlenose dolphin#Reproduction|Dusky dolphin#Social behavior and reproduction|Short-beaked common dolphin#Reproduction}}
[[File:cmglee Horniman dolphin skin skeleton.jpg|thumb|A skin-skeletal preparation<!-- of what?! -->.]]

Dolphin [[copulation (zoology)|copulation]] happens belly to belly; though many species engage in lengthy [[foreplay]], the actual act is usually brief, but may be repeated several times within a short timespan.<ref name=Silva>{{cite web|first1=J. Jr. |last1=Silva |first2=F. |last2=Silva |first3=I. |last3=Sazima |year=2005 |url=http://mardecetaceos.net/media_files/download/04spinner-dolphin.pdf |title=Rest, nurture, sex, release, and play: diurnal underwater behaviour of the spinner dolphin at Fernando de Noronha Archipelago, SW Atlantic – Mating behaviour |access-date=March 16, 2014 |url-status=dead |archive-url=https://web.archive.org/web/20140316211613/http://mardecetaceos.net/media_files/download/04spinner-dolphin.pdf |archive-date=March 16, 2014 }}</ref> The [[gestation period]] varies with species; for the small [[tucuxi dolphin]], this period is around 11 to 12 months,<ref>CMS [http://www.cms.int/reports/small_cetaceans/data/S_fluviatilis/s_fluviatilis.htm Sotalia fluviatilis – Reproduction] {{Webarchive|url=https://web.archive.org/web/20130520100257/http://www.cms.int/reports/small_cetaceans/data/S_fluviatilis/s_fluviatilis.htm |date=May 20, 2013 }}, article. Retrieved March 16, 2013.</ref> while for the orca, the gestation period is around 17 months.<ref>[http://marinebio.org/species.asp?id=84 Orcas (Killer Whales), Orcinus orca – Life History], Marinebio.org. Retrieved March 16, 2014.</ref> Typically dolphins give birth to a single calf, which is, unlike most other mammals, born tail first in most cases.<ref name="Simmonds2007">{{cite book|last=Simmonds|first=Mark|title=Whales and Dolphins of the World|url={{google books |plainurl=y |id=TQxyo8O5KD8C|page=32}}|year=2007|publisher=New Holland Publishers|isbn=978-1-84537-820-2|page=32}}{{Dead link|date=March 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> They usually become sexually active at a young age, even before reaching [[sexual maturity]].<ref name=Silva/> The age of sexual maturity varies by species and sex.<ref>{{Cite book
|title=Reproductive Parameters of Dolphins
|author1=W. Perrin |author2=S. Reilly |year=1984|url=http://swfsc.noaa.gov/publications/CR/1984/8470.PDF}}</ref>

Dolphins are known to display [[Animal co-opted sexual behavior|non-reproductive sexual behavior]], engaging in [[Animal sexual behavior#Autoeroticism or masturbation|masturbation]],<ref>{{Cite book |last1=Würsig |first1=Bernd |url=https://books.google.com/books?id=mfjYEAAAQBAJ&pg=PA164 |title=Sex in Cetaceans: Morphology, Behavior, and the Evolution of Sexual Strategies |last2=Orbach |first2=Dara N. |date=2023-09-25 |publisher=Springer Nature |isbn=978-3-031-35651-3 |language=en}}</ref> stimulation of the genital area of other individuals using the [[rostrum (anatomy)|rostrum]] or flippers, and [[Homosexual behavior in animals|homosexual contact]].<ref name=Silva/><ref>{{Cite book
|title=Homosexual Behaviour in Animals – an Evolutionary perspective.
|author1=Volker Sommer |author2=Paul L. Vasey |year=2006
|chapter=Chapter 4
|chapter-url={{google books |plainurl=y |id=KXM3F59y1jkC}}}}</ref><ref>{{Cite book
|title=Biological Exuberance – Animal Homosexuality and Natural Diversity
|author=Bruce Bagemihl
|url={{google books |plainurl=y |id=0xpi2NI-Dz4C}}
|year=1999}}</ref>

Various species of dolphin have been known to engage in sexual behavior including copulation with dolphins of other species, and occasionally exhibit [[Cross-species sex|sexual behavior towards other animals]], including humans.<ref>{{Cite news|url=http://www.huffingtonpost.com/2012/09/06/frisky-dolphin-tries-to-get-busy-divers_n_1862148.html|title=SCARY VIDEO: Dolphin Gets Too Frisky With Scuba Divers|first1=David|last1=Moye|date=September 7, 2012|newspaper=HuffPost|access-date=December 30, 2016}}</ref><ref>{{Cite book |author1=Amy Samuels |title=Cetaceans that are typically lonely and seek human company |author2=Lars Bejder |author3=Rochelle Constantine |author4=Sonja Heinrich |year=2003 |pages=266–268 |chapter=chapter 15 Marine Mammals: Fisheries, Tourism and Management Issues |author-link3=Rochelle Constantine |access-date=December 17, 2006 |chapter-url=http://whitelab.biology.dal.ca/lb/Samuels%20Bejder%20et%20al%202003.pdf}}</ref> Sexual encounters may be violent, with male bottlenose dolphins sometimes showing aggressive behavior towards both females and other males.<ref>{{cite journal|last=Scott|first=Erin|author2=Mann, Janet |author3=Watson-Capps, Jana |author4=Sargeant, Brooke |author5= Connor, Richard |s2cid=4502911|title=Aggression in bottlenose dolphins: Evidence for sexual coercion, male-male competition, and female tolerance through analysis of tooth-rake marks and behaviour|journal=Behaviour|year=2005|volume=142|issue=1|pages=21–44|doi=10.1163/1568539053627712}}</ref> Male dolphins may also work together and attempt to herd females in [[Estrus#Estrus|estrus]], keeping the females by their side by means of both physical aggression and intimidation, to increase their chances of reproductive success.<ref>{{Cite book
|title=Two levels of alliance formation among male bottlenose dolphins
|author1=R. Connor |author2=R. Smolker |author3=A. Richards |year=1992|url=http://www.pnas.org/content/89/3/987.full.pdf}}</ref>