COMPARATIVE BLOG

SOCIALITY AND MATING PATTERNS

LEMURS

1.    Lemurs are found in Madagascar, in the treetops of the rainforest, in the desert and on the Comoros Islands.
2.   Ringtail lemurs live in groups of male and females of about 11-17. When a group gets too large, usually 15-25, with too many females, the lemurs will break apart and form two smaller groups. In the lemur family females are usually dominant. Usually, a group of lemurs will have one female who is the leader and controls their movement, and who has first choice in food and mates. They do not begin reproducing until about 2.5-4 years old. Females are usually sexually active for one or two days a year and tend to give birth to one child. However, lemurs in captivity tend to break these trends an
3. Ringtail lemurs’ reproductive success is very dependent on environmental conditions, as is their sociality. For instance, in years of drought infant mortality rates are around 80% but normally the rates are around 37%.

*http://pin.primate.wisc.edu/factsheets/entry/ring-tailed_lemur/behav

Spider monkeys

1.             Spider monkeys can often be found in the tropical rain forests of Central and South America and additionally further north in Mexico.
2.       Spider monkeys are social and gather in large groups, however they usually break apart into small sub groups, led by females, in order to gather food and to sleep. A female spider monkey’s period of sexual receptivity lasts for about 8 to 10 days with periods between peaks of sexual receptivity lasting 15-17 days.
3.        The reason that spider monkeys break into smaller sub groups is because of seasonal fruit shortages. Thus, to avoid competition and in order to gain more food per member, the spider monkeys break into smaller groups. When food opportunities are at their scarcest the sub groups are at their smallest and when opportunities are at their peak, groups are largest. One of the reasons that the spider monkeys continue to socialize in larger groups is for increased mating opportunities and for protection. If there are no males in a female’s subgroup then she will lead her group to the calls of neighboring males. Therefore, sociality and mating patterns depend heavily on the spider monkey’s food opportunities in their environment. 

*         *http://animals.nationalgeographic.com/animals/mammals/spider-monkey/#

           *http://pin.primate.wisc.edu/factsheets/entry/black_spider_monkey/behav

Baboon

1.     Baboons almost exclusively live in Africa or Arabia. They generally prefer savanna and other semi-arid habitats, though some live in tropical forests.

2.     Baboons live in groups known as “troops.” These troops usually consist of 15-150 baboons. While females tend to stay in the same group almost their entire lives, males often venture out and change groups several times, starting when they reach puberty between the ages of six and nine. Females in a group tend to all be related and are close to each other but males, since they venture out, are usually competitive for access to females. Male and female baboons often form close friendships with each other that consist of frequent, relaxed grooming sessions, traveling and foraging together, sleeping never each other, defense from aggressive predators, and support in caring for infants. Male and female baboons reach sexual maturity between 4 and 6 years of age. They are sexually promiscuous, often having several mates. Baboons often form mating consorts, in which males and sexually receptive females stay close to one another during the duration that the female is receptive. The male will stay close to the female and will fend off any other males who try to mate with her, resulting is severe fights. Females are involved in consorts with an average of three to four males and ranging up to nine different males during the period of her fertility.

3.     Because the females stay with the same groups their entire lives they form a hierarchal relationship but are still very close. But because the males are constantly moving groups in order to prevent mating with their own offspring, they are constantly at competition with each other for new mates and other resources.

*http://animals.nationalgeographic.com/animals/mammals/baboon/

*http://pin.primate.wisc.edu/factsheets/entry/olive_baboon/behav

Gibbon

1. Gibbons are found in the dense forests of southern Asia, and rarely descend down from the trees.
2. Gibbons usually live in serious monogamous pairs with up to four offspring. However, some gibbons are known to live in all male groups or all female groups. Though there is no definite leader, females usually take the lead in group progressions. Despite most gibbons being monogamous, when it comes to reproduction some of them are polygamous. However, frequency of copulation remains highest with their pair mates. Mating occurs ever month but most conceptions occur during the dry season.
3.  Because they live almost exclusively in the trees Gibbons are endangered and are having a hard time adapting to the loss of their forest. 

*http://animals.nationalgeographic.com/animals/mammals/gibbon/

*http://pin.primate.wisc.edu/factsheets/entry/lar_gibbon/behav

Chimpanzee

1. Chimpanzees habitat African rain forests, woodlands and grasslands.
2. Chimpanzees live in social communities of several dozen animals. Males are dominant over females and tend to remain in their communities while adolescent females tend to emigrate. Males tend to be more closely related which results in them having closer bonds than the female chimpanzees. The communities usually break off into small groups for hunting. Mating occurs throughout the year and both males and females are promiscuous. The number of estrous females is directly related to food abundance, because of the energy required for ovulation and mating.
3. Being in a group allows them to hunt more and gain more food. This allows the females to be ready to mate more frequently and produce more offspring.   

 *http://animals.nationalgeographic.com/animals/mammals/chimpanzee/

*http://pin.primate.wisc.edu/factsheets/entry/chimpanzee/behav

It seems that environment does play a key role in the sociality and mating patterns of these primates. It's interesting that the female tends to be the leader in all the groups except for the chimpanzees. As long as these primate stick to their social norms  and continue to hunt and gather their food it will allow them to have more reproductive opportunities and adapt to future environments.