Editing Sexual selection (section)

=== Male intrasexual competition ===

[[File:Susa group, mountain gorilla.jpg|thumb|upright=0.8|Male [[mountain gorilla]], a species with very large males<ref>{{cite book |last1=Williamson |first1=E. A. |last2=Butynski |first2=T. M. |year=2013 |title=Mammals of Africa |volume=2. Primates |editor1=Butynski, T. M. |editor2=Kingdon, J. |editor3=Kalina, J. |isbn=9781408189962 |location=London, New Delhi, New York, Sydney |publisher=Bloomsbury |pages=45–53 |chapter=''Gorilla beringei'' eastern gorilla |chapter-url=https://books.google.com/books?id=B_07noCPc4kC&pg=RA1-PA45}}</ref>|alt=Photograph of a large male gorilla]]

{{Main|Male intrasexual competition}}

Male–male competition occurs when two males of the same species compete for the opportunity to mate with a female. Sexually dimorphic traits, size, sex ratio,<ref name="Weir 2012">{{Cite journal |last=Weir |first=Laura K. |date=2012-11-22 |title=Male–male competition and alternative male mating tactics influence female behavior and fertility in Japanese medaka (Oryzias latipes) |journal=Behavioral Ecology and Sociobiology |volume=67 |issue=2 |pages=193–203 |doi=10.1007/s00265-012-1438-9 |s2cid=15410498 }}</ref> and the social situation<ref name="Proctor-2012">{{Cite journal |last1=Proctor |first1=D. S. |last2=Moore |first2=A. J. |last3=Miller |first3=C. W. |date=2012-03-09 |title=The form of sexual selection arising from male–male competition depends on the presence of females in the social environment |journal=Journal of Evolutionary Biology |volume=25 |issue=5 |pages=803–812 |doi=10.1111/j.1420-9101.2012.02485.x |pmid=22404372 |s2cid=594384 }}</ref> may all play a role in the effects male–male competition has on the reproductive success of a male and the mate choice of a female. Larger males tend to win male–male conflicts.<ref>{{Cite journal |last=Otronen |first=Merja |date=1984-08-01 |title=Male contests for territories and females in the fly Dryomyza Anilis |journal=Animal Behaviour |volume=32 |issue=3 |pages=891–898 |doi=10.1016/S0003-3472(84)80167-0 |s2cid=53188298 }}</ref> Males take many risks in such conflicts, so the value of the resource must be large enough to justify those risks.<ref name="Nelson-Flower 2015">{{Cite journal |last1=Nelson-Flower |first1=Martha J. |last2=Ridley |first2=Amanda R. |date=2015-09-24 |title=Male–male competition is not costly to dominant males in a cooperatively breeding bird |journal=Behavioral Ecology and Sociobiology |volume=69 |issue=12 |pages=1997–2004 |doi=10.1007/s00265-015-2011-0 |bibcode=2015BEcoS..69.1997N |s2cid=15032582 |issn=0340-5443}}</ref><ref name="Luo 2016">{{Cite journal |last1=Luo |first1=Zhenhua |last2=Li |first2=Chenliang |last3=Wang |first3=Hui |last4=Shen |first4=Hang |last5=Zhao |first5=Mian |last6=Gu |first6=Qi |last7=Liao |first7=Chunlin |last8=Gu |first8=Zhirong |last9=Wu |first9=Hua |display-authors=3 |date=2016-02-23 |title=Male–male competition drives sexual selection and group spawning in the Omei treefrog, Rhacophorus omeimontis |journal=Behavioral Ecology and Sociobiology |volume=70 |issue=4 |pages=593–605 |doi=10.1007/s00265-016-2078-2 |bibcode=2016BEcoS..70..593L |s2cid=13912038 |issn=0340-5443}}</ref> [[Winner and loser effects]] further influence male behaviour.<ref name="Zeng 2018">{{Cite journal |last1=Zeng |first1=Yang |last2=Zhou |first2=Feng-Hao |last3=Zhu |first3=Dao-Hong |date=2018-06-26 |title=Fight outcome briefly affects the reproductive fitness of male crickets |journal=Scientific Reports |volume=8 |issue=1 |pages=9695 |doi=10.1038/s41598-018-27866-4  |pmc=6018733 |pmid=29946077 |bibcode=2018NatSR...8.9695Z }}</ref> Male–male competition may also affect a female's ability to select the best mates, and therefore decrease the likelihood of successful reproduction.<ref name="Cayuela 2016">{{Cite journal |last1=Cayuela |first1=Hugo |last2=Lengagne |first2=Thierry |last3=Kaufmann |first3=Bernard |last4=Joly |first4=Pierre |last5=Léna |first5=Jean-Paul |date=2016-06-24 |title=Larval competition risk shapes male–male competition and mating behavior in an anuran |journal=Behavioral Ecology |volume=27 |issue=6 |pages=arw100 |doi=10.1093/beheco/arw100 |doi-access=free }}</ref>