Exploring Primate Social Structures and Mating Systems

ANT 251 0 02, 003, & 004 Dr. Clarke Life- The Primates Hamadryas baboon ( Papio hamadryas ): • What type of social organization do we find among P. hamadryas? On the arid steppes of Africa, the hamadryas baboon is a social animal that lives in groups led by a single dominant male and a harem, or group of two or more females and their young. This social structure, known as a multilevel society, has four levels. • P. hamadryas have a polygynous mating system (female defense or harem style). Please list three characteristics of this type of system. The polygyny threshold model explains polygyny, or the mating of one male of a species with many females. Females might improve their biological fitness by mating with a guy who already has a partner. Even with two females on the territory, the female makes this decision despite the presence of other males because the selected male's genetics, territory, food supply, or other critical attributes outperform those of his competitors. • Describe the social hierarchy of P. hamadryas .

A unique four-level social structure known as a multilevel society is seen in the Hamadryas baboon. With one male and up to ten females in tiny groups known as "harems," which the men lead and protect, most social contact takes place. One common feature of a harem is a younger male "follower" who may be someone's relative. Japanese macaque ( Macaca fuscata ): • Describe the social hierarchy of this species and how it relates to the hot springs. In Japanese macaque communities, there is a significant social hierarchy, with various advantages for higher-ranking individuals, such as early access to food. Daughters inherit their mother's social standing, while younger siblings often outrank their elder siblings in the social order.

• Macaques are a female philopatric species. What sort of inter-female relationships might you expect to see? Philopatry is an organism's proclivity to remain in or routinely return to a certain location. There are several reasons of philopatry, but natal philopatry, in which animals return to their birthplace to procreate, may be the most prevalent. Animals that return to the same region to reproduce despite not having been born there, as well as migratory species that display site fidelity by repeating stopovers, staging areas, and wintering grounds, are examples of recent utilization. • M. fuscata live in multi-male/multi-female groups and they have a promiscuous mating system. Do you expect to see male investment in offspring? Why or why not? If it is the usual for men in a community to sire kids with more than one female, and each man is more or less equally successful in fathering children, the mating system is really promiscuous. Western gorilla ( Gorilla gorilla ):

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

• Describe the social hierarchy for G. gorilla . Gorilla groups are hierarchical, with the dominant male serving as the leader. The dominant male is in charge of defending the group and mating with the females. Within a colony, gorillas engage in social behaviors such as grooming, playing, and communicating through vocalizations and body language1. Gorillas utilize vocalizations to express emotions such as happiness, sadness, pain, or fear. • G. gorilla have a polygynous mating system. What are the costs and benefits for male gorillas in this type of system? • Costs: Because the sex ratio at birth is 50:50, a large number of men are left without a group of females. Males will sometimes establish bachelor groups, which are informal groupings of immature males who move and eat together until each male is able to take over a group of females. • Benefits: In some areas, researchers have documented groups with two silverbacks. In these cases, an adult son of the dominant male remains in the group to help protect it against take-overs by unrelated males.

Spectral tarsier ( Tarsius tarsier ): • Based on your knowledge from class/readings what type of social organization do the majority of tarsier species live in? Tarsiers have a complex social structure. They can live in monogamous pairs or in alloparental family groupings. Tarsiers are arboreal clingers and leapers, and olfactory and auditory communication are the most vital due to their nocturnal lifestyle.

• How do tarsiers communicate with each other? What reasons do they have to communicate? Tarsier pairs engage in complicated duet sounds, which are most likely to occur around daybreak when the tarsiers prepare to sleep. Scientists think the tarsier couple is informing other tarsiers in the vicinity about their pair connection. The duo may also be used to negotiate territory disputes. Phayre’s leaf monkey ( Trachypithecus phayrei ): • Why are infant leaf monkeys’ bright orange? Leaf monkey infants are orange to help moms find them as they wander the jungle. The orange tint allows them to blend in with their environment and hide from predators.

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

• Describe the social system of T. phayrei , especially in relation to infant care. The Phayre's langur often forms multi-male and multi-female groups with a dominant male alpha present. All-male, one-male, and one-female groupings have also been seen, albeit these are less common. Within the species and within groups, there is a high level of territoriality. Ring-tailed lemur ( Lemur catta ):

• Ring-tailed lemurs live in fairly large groups up to 30 individuals). Please give two factors that can influence group size. Males tend to shift groups when they attain sexual maturity at the age of three, whilst females stay their whole lives in their natal group. These groups are female dominant, a feature shared by lemurs, which means the females have preferred access to food and a say in who they mate with. Males and females both have a dominance hierarchy. • Explain how male and female ring-tailed lemurs use scent as a means of communication. Ring-tailed lemurs have powerful smell glands and use their distinct odor as a form of communication and even as a weapon. Lemurs mark their territory with scent, alerting anybody who can smell them of their presence. During mating season, male lemurs compete for supremacy by outstinking one another.

Bornean orangutan ( Pongo pygmaeus ): • Based on your knowledge from class/readings what type of mating system does this species have? List three characteristics that characterize this system. Bornean orangutans' mating systems can be classed as polygynous with subtleties. It's more of an intrasexual rivalry amongst flanged males. During times of food plenty, females have increased ovarian function.

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Questions for Life Primates

Related Documents