Editing Vervet monkey (section)

== Behaviour ==

===Social behaviour===
[[File:Vervet monkeys grooming.JPG|thumb|left|A vervet monkey grooms another in Gaborone, Botswana]]
[[File:Vervet monkey (Chlorocebus pygerythrus rufoviridis) juvenile, Semliki Wildlife Reserve.jpg|thumb|right|Juvenile ''C. p. rufoviridis'', [[Uganda]]]]
When males reach sexual maturity, they move to a neighboring group.<ref>{{cite journal|last1=Pasternak|first1=G.|last2=Brown|first2=L.|last3=Kienzle|first3=S.|last4=Fuller|first4=A.|last5=Barrett|first5=L.|last6=Henzi|first6=P.|title=Population ecology of vervet monkey in a high latitude, semi-arid riparian woodland|journal=Koedoe|date=2013|volume=55|issue=1|doi=10.4102/koedoe.v55i1.1078|doi-access=free|hdl=10500/8791|hdl-access=free}}</ref> Often, males move with a brother or peer, presumably for protection against aggression by males and females of the resident group. Groups that had previously transferred males show significantly less aggression upon the arrival of another male. In almost every case, males migrate to adjacent groups. This obviously increases benefits in regard to distance traveled, but also reduces the amount of genetic variance, increasing the likelihood of [[inbreeding]].<ref name="dispersal">{{cite journal| last = Cheney| first = D. L.|author2=Seyfarth, R. M. | title = Nonrandom dispersal in free-ranging vervet monkeys: social and genetic consequences| journal = [[The American Naturalist]]| volume =122| issue =3| pages =392–412| date =September 1983| jstor =2461023| doi = 10.1086/284142 | s2cid = 84820877}}</ref>

Females remain in their groups throughout life. Separate [[Dominance hierarchy|dominance hierarchies]] are found for each sex. Male hierarchies are determined by age, tenure in the group, fighting abilities, and allies, while female hierarchies are dependent on maternal social status. A large proportion of interactions occurs between individuals that are similarly ranked and closely related. Between unrelated individuals, female competition exists for grooming members of high-ranking families, presumably to gain more access to resources. These observations suggest individual recognition is possible and enables discrimination of genetic relatedness and social status. Interactions between different groups are variable, ranging from highly aggressive to friendly. Furthermore, individuals seem to be able to recognise cross-group vocalisations, and identify from and to which monkey each call is intended, even if the call is made by a subadult male, which is likely to transfer groups. This suggests the members within a group are actively monitoring the activity of other groups, including the movement of individuals within a group.<ref name="individuals">{{cite journal| last = Cheney| first = D. L.|author2=Seyfarth, R. M. | title =Recognition of individuals within and between groups of free-ranging vervet monkeys| journal = [[American Zoologist]]| volume =22| issue =3| pages =519–529| date =1982| jstor= 3882575| doi=10.1093/icb/22.3.519| doi-access =free}}</ref>

Within groups, aggression is directed primarily at individuals that are lower on the hierarchy. Once an individual is three years or older, it is considerably more likely to be involved in conflict. Conflict often arises when one group member shows aggression toward a close relative of another. Further, both males and females may redirect aggression towards individuals in which both had close relatives that were previously involved in a conflict. This suggests complex recognition not only of individuals, but also of associations between individuals. This does not suggest recognition of other's individual kinship bonds is possible, but rather that discrimination of social relationships does occur.<ref name="socialally">{{cite journal| last = Cheney| first = D. L.|author2=Seyfarth, R. M. | title =The recognition of social alliances by vervet monkeys|journal = [[Animal Behaviour (journal)|Animal Behaviour]]| volume =34| issue = 6| pages =1722–1731| date =1986| doi = 10.1016/S0003-3472(86)80259-7| s2cid = 53184485| doi-access = free}}</ref>
[[File:Vervet monkeys Kruger.jpg|thumb|upright|Female and juvenile, [[Kruger Park]], [[South Africa]]]]

=== Alarm calls and offspring recognition ===
Vervet monkeys have four confirmed [[predator]]s: leopards, eagles, pythons, and baboons. The sighting of each predator elicits an acoustically distinct alarm call.<ref name="alarm">{{cite journal| last = Seyfarth| first = R. M. |author2=Cheney, D. L |author3=Marler, P.| title =Vervet monkey alarm calls: semantic communication in a free-ranging primate|journal = [[Animal Behaviour (journal)|Animal Behaviour]]| volume =28 | issue = 4| pages =1070–1094| date =1980| doi = 10.1016/S0003-3472(80)80097-2| s2cid = 53165940 }}</ref> As infants, vervets learn to make the variety of calls from observation alone, without explicit tutelage. In experimentation with unreliable signalers, individuals became habituated to incorrect calls from a specific individual. Though the response was lessened for a specific predator, if an unreliable individual gives an [[alarm call]] for a different predator, group members respond as if the alarm caller is, in fact, reliable. This suggests vervet monkeys are able to recognize and to respond to not only the individual calling, but also to the semantics of what the individual is communicating.<ref name="fakealarm">{{cite journal| last = Cheney| first = D. L.|author2=Seyfarth, R.M. | title =Assessment of meaning and the detection of unreliable signals by vervet monkeys|journal = [[Animal Behaviour (journal)|Animal Behaviour]]| volume =36| issue = 2| pages =477–486| date =1988| doi = 10.1016/S0003-3472(88)80018-6| s2cid = 53167785}}</ref> Vervet monkeys are thought to have up to 30 different alarm calls. In the wild, they have been seen giving a different call when seeing a human being approaching, leading researchers to believe that vervet monkeys may have a way of distinguishing between different land and flight predators.<ref>{{cite book|last1=Estes|first1=Richard Despard|title=The behaviour guide to African mammals|date=2012|publisher=University of California press|location=London England|edition=20th Anniversary}}</ref>

Mothers can recognise their offspring by a scream alone. A juvenile scream elicits a reaction from all mothers, yet the juvenile's own mother has a shorter latency in looking in the direction of the scream, as well as an increased duration in her look. Further, mothers have been observed to help their offspring in conflict, yet rarely aid other juveniles. Other mothers evidently can determine to which mother the offspring belongs. Individuals have been observed to look towards the mother whose offspring is creating the scream.<ref name="vocalrecog">{{cite journal| last = Cheney| first = D. L.|author2=Seyfarth, R. M. | title =Vocal recognition in free-ranging vervet monkeys|journal = [[Animal Behaviour (journal)|Animal Behaviour]]| volume =28| issue = 2| pages =362–367| date =1980| doi = 10.1016/S0003-3472(80)80044-3| s2cid = 53258798}}</ref>

=== Kin relationships ===
Siblings likely provide the prevailing social relationships during development. Within social groups, mother-offspring and sibling interactive units are distinct groups. The sibling interactions are heavily supportive and friendly, but do have some competition. Contests primarily involve postweaning resource allocation by the common mother. For example, siblings have conflict over grooming time allocated by their mother. Offspring are usually not born in extremely close time proximity due to the interbirth period of the mother. This time can be reduced by use of an [[Alloparenting|allomother]]. The clarity of the familial and sibships within a group may act as a form of alliance, which would come at relatively low cost in regards to grooming. Other alliances are shown through conflict with aggressive individuals that have acted against a closely related sibling.<ref name="sibships">{{cite journal| last = Lee| first = P.C.| title =Sibships: cooperation and competition among immature vervet monkeys|journal =[[Primates (journal)|Primates]]| volume =28| issue =1| pages =47–59| date =1987| doi = 10.1007/BF02382182| s2cid = 21449948}}</ref>
[[Image:Vervet monkey and baby.jpg|thumb|left|Vervet monkey female with a baby]]

Allomothering is the process when another individual besides the mother cares for an infant. In groups of vervet monkeys, infants are the target of a tremendous amount of attention. Days after an infant is born, every member of the group inspects the infant at least once by touching or sniffing. While all group members participate in infant caretaking, [[juvenile (organism)|juvenile]] females that cannot yet [[menstruate]] are responsible for the majority of allomothering. The benefit is mutual for the mother and allomother. Mothers that use allomothers are able to shorten their interbirth periods, the time between successive births. At the same time, allomothers gain experience in rearing infants, and had more success in raising their own offspring. Juvenile females discriminate in preference for the infant they choose to allomother, and usually choose siblings or infants of high-ranking individuals. When a mother allows her juvenile daughter to become an allomother for a newborn sibling, the mother decreases her own investment in the infant, while increasing the chances of successful rearing of her immature daughter.<ref name="allomother">{{cite journal| last = Fairbanks| first = L. A.| title =Reciprocal benefits of allomothering for female vervet monkeys|journal = [[Animal Behaviour (journal)|Animal Behaviour]]| volume =40| pages =553–562| date =1990| doi = 10.1016/S0003-3472(05)80536-6| issue = 3| s2cid = 53193890}}</ref>

Grandmothers and grandchildren share one-quarter of their genes, so they should be more likely to form affiliative relationships than unrelated members in a group. Not only do infants approach their grandmothers more often than unrelated members, but they also prefer their grandmothers compared to other adult female kin, not including their own mothers. Additional research has shown grandmothers show no preference over the sex of their grandchild. Interest in the grandchild spurred from the rank of the grandmother within a group. Higher-ranking grandmothers showed more interest in caring for their grandchildren when compared to low-ranking grandmothers. The presence of grandmothers has been associated with a decrease in mortality of infants.<ref name="grandmothers">{{cite journal| last = Fairbanks| first = L. A.| title =Vervet monkey grandmothers: interactions with infant grandoffspring| journal = [[International Journal of Primatology]]| volume =9| issue =5|pages =426–441| date =1988| doi=10.1007/bf02736218| s2cid = 6784648}}</ref>

=== Spite ===

[[Spite (sentiment)|Spite]]ful actions are extremely rare in the animal kingdom. Often, an indirect benefit is gained by the individual acting 'spitefully', or by a close relative of that individual. Vervet monkeys have been observed to destroy a competitor's food source rather than consume or steal it themselves. While energy is being lost on destroying the food, an advantage is obtained by the individual due to an increase in competitive gain. This would be pertinent for a male that could be displaced within his group by [[immigrating]] males.<ref name="spite">{{cite journal| last = Horrocks| first = J.|author2=Hunte, W. | title ='Spite'; a constraint on optimal foraging in the vervet monkey ''Cercopithecus aethiops sabaeus'' in Barbados| journal = [[American Zoology]]| volume =21| page =939| date =1981}}</ref>

=== Reproduction ===
Female vervets do not have external signs indicating [[estrus]], thus elaborate social behaviors involving reproduction do not occur. Typically, a female gives birth once a year, between September and February, after a [[gestation period]] around 165 days. Usually, only one infant is born at a time, though twins can occur rarely. A normal infant weighs {{convert|300–400|g|oz}}.<ref name="Skinner1990"/>