Editing Behavioral ecology (section)

==Sexual conflict==
[[Sexual conflict]], in some form or another, may very well be inherent in the ways most animals reproduce.<ref>{{cite journal | last1 = Parker | first1 = G. A. | year = 2006 | title = Sexual conflict over mating and fertilization: An overview | journal = Philosophical Transactions of the Royal Society B | volume = 361 | issue = 1466| pages = 235–259 | doi=10.1098/rstb.2005.1785 | pmid=16612884 | pmc=1569603}}</ref>  Females invest more in offspring prior to mating, due to the differences in gametes in species that exhibit anisogamy, and often invest more in offspring after mating.<ref name ="Davies209-220">Davies N, Krebs J, and West S. (2012). An Introduction to Behavioral Ecology, 4th Ed. Wiley-Blackwell; Oxford: pp. 209–220.{{ISBN?}}</ref>  This unequal investment leads, on one hand, to intense competition between males for mates and, on the other hand, to females choosing among males for better access to resources and good genes.  Because of differences in mating goals, males and females may have very different preferred outcomes to mating.

Sexual conflict occurs whenever the preferred outcome of mating is different for the male and female.  This difference, in theory, should lead to each sex evolving adaptations that bias the outcome of reproduction towards its own interests.  This sexual competition leads to sexually antagonistic coevolution between males and females, resulting in what has been described as an [[evolutionary arms race]] between [[male]]s and [[female]]s.<ref>Parker, G. (1979). "Sexual selection and sexual conflict." In: ''Sexual Selection and Reproductive Competition in Insects'' (eds. M.S. Blum and N.A. Blum). Academic Press, New York: pp. 123–166.{{ISBN?}}</ref><ref>{{cite journal | last1 = Chapman | first1 = T. | year = 2003 | title = Sexual Selection | journal = Trends in Ecology and Evolution | volume = 18 | pages = 41–47 | doi=10.1016/s0169-5347(02)00004-6|display-authors=etal}}</ref>

===Conflict over mating===
[[File:Panorpa communis V.jpg|thumb|upright|left|[[Panorpa communis|Male scorpionfly]]]]
Males' reproductive successes are often limited by access to mates, whereas females' reproductive successes are more often limited by access to resources.  Thus, for a given sexual encounter, it benefits the male to mate, but benefits the female to be choosy and resist.<ref name="Davies209-220"/>  For example, male [[small tortoiseshell]] butterfly compete to gain the best territory to mate.<ref name="Baker" />  Another example of this conflict can be found in the Eastern carpenter bee, ''[[Eastern carpenter bee|Xylocopa virginica]]''.  Males of this species are limited in reproduction primarily by access to mates, so they claim a territory and wait for a female to pass through.  Big males are, therefore, more successful in mating because they claim territories near the female nesting sites that are more sought after.  Smaller males, on the other hand, monopolize less competitive sites in foraging areas so that they may mate with reduced conflict.<ref>{{cite journal | last1 = Skandalis | first1 = Dimitri A. | last2 = Tattersall | first2 = Glenn J. | last3 = Prager | first3 = Sean | last4 = Richards | first4 = Miriam H. | year = 2009 | title = Body Size and Shape of the Large Carpenter Bee, ''Xylocopa virginica'' (L.) (Hymenoptera: Apidae) | journal = Journal of the Kansas Entomological Society | volume = 82 | issue = 1| pages = 30–42 | doi = 10.2317/JKES711.05.1 | s2cid = 73520512 }}</ref> Another example of this is ''[[Sepsis cynipsea]],'' where males of the species mount females to guard them from other males and remain on the female, attempting to copulate, until the female either shakes them off or consents to mating.<ref>{{cite journal | last1 = Blanckenhorn | first1 = W.U. | last2 = Mühlhäuser | first2 = C. | last3 = Morf | first3 = C. | last4 = Reusch | first4 = T. | last5 = Reuter | first5 = M. | year = 2000 | title = Female choice, female reluctance to mate and sexual selection on body size in the dung fly ''Sepsis cynipsea'' | journal = Ethology | volume = 106 | issue = 7| pages = 577–593 | doi = 10.1046/j.1439-0310.2000.00573.x }}</ref> Similarly the neriid fly ''[[Derocephalus angusticollis]]'' demonstrates mate guarding by using their long limbs to hold onto the female as well as push other males away during copulation.<ref>{{Cite journal|last=Bonduriansky|first=Russell|date=2006|title=Convergent evolution of sexual shape dimorphism in Diptera|journal=Journal of Morphology|language=en|volume=267|issue=5|pages=602–611|doi=10.1002/jmor.10426|pmid=16477603|s2cid=15548020|issn=1097-4687}}</ref> Extreme manifestations of this conflict are seen throughout nature.  For example, the male ''[[Panorpa]]'' scorpionflies attempt to force copulation.  Male scorpionflies usually acquire mates by presenting them with edible nuptial gifts in the forms of salivary secretions or dead insects.  However, some males attempt to force copulation by grabbing females with a specialized abdominal organ without offering a gift.<ref>{{cite journal | last1 = Thornhill | first1 = R. | year = 1980 | title = Rape in Panorpa scorpionflies and a general rape hypothesis | journal = Animal Behaviour | volume = 28 | pages = 52–59 | doi=10.1016/s0003-3472(80)80007-8| s2cid = 53167007 }}</ref> [[Forced copulation]] is costly to the female as she does not receive the food from the male and has to search for food herself (costing time and energy), while it is beneficial for the male as he does not need to find a nuptial gift.

In other cases, however, it pays for the female to gain more matings and her social mate to prevent these so as to guard paternity.  For example, in many socially monogamous birds, males follow females closely during their fertile periods and attempt to chase away any other males to prevent extra-pair matings.  The female may attempt to sneak off to achieve these extra matings.  In species where males are incapable of constant guarding, the social male may frequently copulate with the female so as to swamp rival males' sperm.<ref>{{cite book|last1=Birkhead|first1=Tim|last2=Moller|first2=A.|year=1992|title=Sperm Competition in Birds: Evolutionary Causes and Consequences|publisher=Academic Press|location=London|oclc=25578404}}{{ISBN?}}{{Page needed|date=July 2021}}</ref>

[[File:Gallus gallus female - Kaeng Krachan.jpg|thumb|Female [[red junglefowl]] in Thailand]]

Sexual conflict after mating has also been shown to occur in both males and females.  Males employ a diverse array of tactics to increase their success in [[sperm competition]]. These can include removing other male's sperm from females, displacing other male's sperm by flushing out prior inseminations with large amounts of their own sperm, creating [[copulatory plug]]s in females' reproductive tracts to prevent future matings with other males, spraying females with anti-aphrodisiacs to discourage other males from mating with the female, and producing sterile parasperm to protect fertile eusperm in the female's reproductive tract.<ref name="Davies209-220"/> For example, the male spruce bud moth (''[[Zeiraphera canadensis]])'' secretes an accessory gland protein during mating that makes them unattractive to other males and thus prevents females from future copulation.<ref>{{Cite journal|url=http://www.nrcresearchpress.com/doi/abs/10.1139/z94-284|doi = 10.1139/z94-284|title = Interactions between body size and mating history influence the reproductive success of males of a tortricid moth, Zeiraphera canadensis|year = 1994|last1 = Carroll|first1 = Allan L.|journal = Canadian Journal of Zoology|volume = 72|issue = 12|pages = 2124–2132|url-access = subscription}}</ref> The [[Parnassius smintheus|Rocky Mountain parnassian]] also exhibits this type of sexual conflict when the male butterflies deposit a waxy genital plug onto the tip of the female's abdomen that physically prevents the female from mating again.<ref>{{cite book|last1=Shepard|first1=Jon|last2=Guppy|first2=Crispin|title=Butterflies of British Columbia: Including Western Alberta, Southern Yukon, the Alaska Panhandle, Washington, Northern Oregon, Northern Idaho, and Northwestern Montana|date=2011|publisher=UBC Press|isbn=978-0-7748-4437-6|url=https://books.google.com/books?id=il6rJ7glHNQC&q=parnassius+smintheus+sphragis&pg=PA53|access-date=13 November 2017|language=en}}</ref> Males can also prevent future mating by transferring an anti-Aphrodiasic to the female during mating. This behavior is seen in butterfly species such as ''[[Heliconius melpomene]]'', where males transfer a compound that causes the female to smell like a male butterfly and thus deter any future potential mates.<ref>{{Cite journal|last1=Schulz|first1=Stefan|last2=Estrada|first2=Catalina|last3=Yildizhan|first3=Selma|last4=Boppré|first4=Michael|last5=Gilbert|first5=Lawrence E.|date=2008-01-01|title=An antiaphrodisiac in ''Heliconius melpomene'' butterflies|journal=Journal of Chemical Ecology|language=en|volume=34|issue=1|pages=82–93|doi=10.1007/s10886-007-9393-z|pmid=18080165|s2cid=22090974|issn=0098-0331}}</ref> Furthermore, males may control the strategic allocation of sperm, producing more sperm when females are more promiscuous.  All these methods are meant to ensure that females are more likely to produce offspring belonging to the males who uses the method.<ref name="Davies209-220"/>

Females also control the outcomes of matings, and there exists the possibility that females choose sperm (cryptic female choice).<ref name="Davies209-220"/>  A dramatic example of this is the [[feral]] [[fowl]] ''[[Gallus gallus]]''.  In this species, females prefer to copulate with dominant males, but subordinate males can force matings.  In these cases, the female is able to eject the subordinate male's sperm using cloacal contractions.<ref>{{cite journal | last1 = Pizzari | first1 = T. | last2 = Birkhead | first2 = T. | year = 2000 | title = Female feral fowl eject sperm of subdominant males | journal = Nature | volume = 405 | issue = 6788| pages = 787–789 |bibcode = 2000Natur.405..787P | doi=10.1038/35015558 | pmid=10866198| s2cid = 4406792 }}</ref>