Editing Night monkey (section)

=== Pair-bonded social animals (social monogamy) ===
Night monkeys are socially monogamous—they form a bond and mate with one partner. They live in small groups consisting of a pair of reproductive adults, one infant and one to two juveniles.<ref name="Fernandez-Duque-2012">{{Cite journal|last=Fernandez-Duque|first=E.|date=January 2012|title=Owl monkeys ''Aotus'' spp in the wild and in captivity|journal=International Zoo Yearbook|volume=46|issue=1|pages=80–94|doi=10.1111/j.1748-1090.2011.00156.x|issn=0074-9664|hdl=11336/101658|hdl-access=free}}</ref> These species exhibit mate guarding, a practice in which the male individual will protect the female he is bonded to and prevent other conspecifics from attempting to mate with her.<ref name="Wartmann-2014">{{Cite journal|last1=Wartmann|first1=Flurina M.|last2=Juárez|first2=Cecilia P.|last3=Fernandez-Duque|first3=Eduardo|date=2014-07-04|title=Erratum to: Size, Site Fidelity, and Overlap of Home Ranges and Core Areas in the Socially Monogamous Owl Monkey (''Aotus azarae'') of Northern Argentina|journal=International Journal of Primatology|volume=35|issue=5|pages=940|doi=10.1007/s10764-014-9787-z|issn=0164-0291|doi-access=free}}</ref>&nbsp; Mate guarding likely evolved as a means of reducing energy expenditure when mating. As night monkey territories generally have some edge overlap, there can be a large number of individuals coexisting in one area which may make it difficult for a male to defend many females at once due to high levels of interspecific competition for mates.<ref>{{Cite journal|last=Fernandez-Duque|first=Eduardo|date=March 2016|title=Social monogamy in wild owl monkeys ( Aotus azarae ) of Argentina: the potential influences of resource distribution and ranging patterns: Monogamy in Owl Monkeys|journal=American Journal of Primatology|language=en|volume=78|issue=3|pages=355–371|doi=10.1002/ajp.22397|pmc=5398412|pmid=25931263}}</ref> Night monkeys form bonded pairs and the energy expenditure of protecting a mate is reduced.<ref name="Wartmann-2014" /> Pair bonding may also be exhibited as a result of food distribution. In the forest, pockets of food can be dense or very patchy and scarce. Females, as they need energy stores to support reproduction are generally distributed to areas with sufficient food sources.<ref name="Fernandez-Duque-2015">{{Cite journal|last=Fernandez- Duque|first=E|date=2015|title=Love in the time of Monkeys|journal=Natural History|volume=122|jstor=}}</ref> Males will therefore also have to distribute themselves to be within proximity to females, this form of food distribution lends itself to social monogamy as finding females may become difficult if males have to constantly search for females which may be widely distributed depending on food availability that year.<ref name="Fernandez-Duque-2015" />

However, while this does explain social monogamy, it does not explain the high degree of paternal care which is exhibited by these primates. After the birth of an infant, males are the primary carrier of the infant, carrying offspring up to 90% of the time.<ref name="Fernandez-Duque-2012" /> In addition to aiding in child care, males will support females during lactation through sharing their foraged food with lactating females.<ref name="Wolovich-2008">{{Cite journal|last1=Wolovich|first1=Christy K.|last2=Evans|first2=Sian|last3=French|first3=Jeffrey A.|date=March 2008|title=Dads do not pay for sex but do buy the milk: food sharing and reproduction in owl monkeys (''Aotus'' spp.)|journal=Animal Behaviour|volume=75|issue=3|pages=1155–1163|doi=10.1016/j.anbehav.2007.09.023|s2cid=36121485|issn=0003-3472}}</ref> Generally, food sharing is not observed in nature as the search for food requires a great degree of energy expenditure, but in the case of night monkey males, food sharing confers offspring survival advantages. As lactating females may be too weak to forage themselves, they may lose the ability to nurse their child, food sharing therefore ensures that offspring will be well feed.<ref name="Wolovich-2008" /> The act of food sharing is only observed among species where there is a high degree of fidelity in paternity. Giving up valuable food sources would not confer an evolutionary advance unless it increased an individual's fitness; in this case, paternal care ensures success of offspring and therefore increases the father's fitness.<ref name="Wolovich-2008" />