Editing Night monkey (section)

=== Nocturnality ===
The family ''Aotidae'' is the only family of nocturnal species within the suborder [[Simian|Anthropoidea]]. Whereas other divisions of primates, including [[Strepsirrhini]] and [[Tarsier|Tarsiidae]], include many nocturnal and cathemeral species, the anthropoids possess very few nocturnal species and therefore it is highly likely that the ancestors of the family ''Aotidae'' did not exhibit nocturnality and were rather diurnal species.<ref name="Ankel-Simons-2008">{{Cite journal|last1=Ankel-Simons|first1=F.|last2=Rasmussen|first2=D.T.|date=2008|title=Diurnality, nocturnality, and the evolution of primate visual systems|journal=American Journal of Physical Anthropology|volume=137|issue=S47|pages=100–117|doi=10.1002/ajpa.20957|pmid=19003895|issn=0002-9483|doi-access=free}}</ref> &nbsp;The presence of nocturnal behavior in ''Aotidae'' therefore exemplifies a derived trait; an evolutionary adaptation that conferred greater fitness advantages onto the night monkey.<ref name="Ankel-Simons-2008" /> &nbsp;Night monkey share some similarities with nocturnal prosimians including low basal metabolic rate, small body size and good ability to detect visual cues at low light levels.<ref name="Wright-1989">{{Cite journal|last=Wright|first=Patricia C.|date=November 1989|title=The nocturnal primate niche in the New World|journal=Journal of Human Evolution|volume=18|issue=7|pages=635–658|doi=10.1016/0047-2484(89)90098-5|bibcode=1989JHumE..18..635W |issn=0047-2484}}</ref> Their responses to olfactory stimulus are intermediate between those of the prosimians and diurnal primate species, however the ability to use auditory cues remains more similar to diurnal primate species than to nocturnal primate species.<ref name="Wright-1989" /> This provides further evidence to support the hypothesis that nocturnality is a derived trait in the family ''Aotidae''.

As the ancestor of ''Aotidae'' was likely diurnal, selective and environmental pressures must have been exerted on the members of this family which subsequently resulted in the alteration of their circadian rhythm to adapt to fill empty niches.<ref name="Ankel-Simons-2008" /> Being active in the night rather than during the day time, gave ''Aotus'' access to better food sources, provided protection from predators, reduced interspecific competition and provided an escape from the harsh environmental conditions of their habitat.<ref name="Fernández-Duque-2010">{{Cite journal|last1=Fernández-Duque|first1=Eduardo|last2=de la Iglesia|first2=Horacio|last3=Erkert|first3=Hans G.|date=2010-09-03|title=Moonstruck Primates: Owl Monkeys (''Aotus'') Need Moonlight for Nocturnal Activity in Their Natural Environment|journal=PLOS ONE|volume=5|issue=9|pages=e12572|doi=10.1371/journal.pone.0012572|pmid=20838447|pmc=2933241|issn=1932-6203|bibcode=2010PLoSO...512572F|doi-access=free}}</ref> To begin, resting during the day allows for decreased interaction with diurnal predators. Members of the family ''Aotidae,'' apply the predation avoidance theory, choosing very strategic covered nests sites in trees.<ref name="Savagian-2017">{{Cite journal|last1=Savagian|first1=Amanda|last2=Fernandez-Duque|first2=Eduardo|date=2017-01-04|title=Do Predators and Thermoregulation Influence Choice of Sleeping Sites and Sleeping Behavior in Azara's Owl Monkeys (''Aotus azarae azarae'') in Northern Argentina?|journal=International Journal of Primatology|volume=38|issue=1|pages=80–99|doi=10.1007/s10764-016-9946-5|s2cid=9881118|issn=0164-0291}}</ref> These primates carefully choose areas with sufficient foliage and vines to provide cover from the sun and camouflage from predators, but which simultaneously allow for visibility of ground predators and permit effective routes of escape should a predator approach too quickly.<ref name="Fernández-Duque-2010" /><ref name="Aquino-1986" /> Activity at night also permits night monkeys to avoid aggressive interactions with other species such as competing for food and territorial disputes; as they are active when most other species are inactive and resting.<ref name="Fernández-Duque-2010" />

Night monkeys also benefit from a nocturnal life style as activity in the night provides a degree of protection from the heat of the day and the thermoregulation difficulties associated.<ref name="Savagian-2017" /> Although night monkey, like all primates are endothermic, meaning they are able to produce their own heat, night monkeys undergo behavioural thermoregulation in order to minimize energy expenditure.<ref name="Savagian-2017" /> During the hottest points of the day, night monkeys are resting and therefore expending less energy in the form of heat. As they carefully construct their nests, night monkeys also benefit from the shade provided by the forest canopy which enables them to cool their bodies through the act of displacing themselves into a shady area.<ref name="Savagian-2017" /> Additionally, finding food is energetically costly and completing this process during the day time usually involves the usage of energy in the form of calories and lipid reserves to cool the body down. Foraging during the night when it is cooler, and when there is less competition, supports the optimal foraging theory; maximize energy input while minimizing energy output.<ref name="Savagian-2017" />

While protection from predators, interspecific interactions, and the harsh environment propose ultimate causes for nocturnal behavior as they increase the species fitness, the proximate causes of nocturnality are linked to the environmental effects on circadian rhythm.<ref name="Fernandez-Duque-2003">{{Cite journal|last=Fernandez-Duque|first=Eduardo|date=2003-09-01|title=Influences of moonlight, ambient temperature, and food availability on the diurnal and nocturnal activity of owl monkeys (''Aotus azarai'')|journal=Behavioral Ecology and Sociobiology|volume=54|issue=5|pages=431–440|doi=10.1007/s00265-003-0637-9|bibcode=2003BEcoS..54..431F |s2cid=32421271|issn=0340-5443|hdl=11336/50695|hdl-access=free}}</ref> While diurnal species are stimulated by the appearance of the sun, in nocturnal species, activity is highly impacted by the degree of moon light available. The presence of a new moon has correlated with inhibition of activity in night monkeys who exhibit lower levels of activity with decreasing levels of moon light.<ref name="Fernandez-Duque-2003" /> Therefore, the lunar cycle has a significant influence on the foraging and a nocturnal behaviors of night monkey species.<ref name="Fernandez-Duque-2003" />