Unit 7
Sociosexual Behaviour: Male Strategies

By now it might appear to you that males have it pretty easy compared to females; free from the constraints of pregnancy, lactation, and, in some cases, any parental investment in offspring, the life of a typical male primate seems to be all about finding a female and occasionally getting something to eat, right? Not exactly! If life were so easy for males we probably would not observe the significant differences in mortality between males and females, in which males typically suffer higher rates than females across all stages of life, and tend to die younger than females. Yet we do see this trend across almost all primate species studied. Males face challenges to their survival and reproductive success just like females. However, due to the evolutionary principles underlying the biology and life history of male mammals, these challenges are often different from those faced by females, and as a result, male strategies for dealing with these challenges also differ from (and are often at odds with) those of females. In this unit, we explore some of these strategies. If female reproductive success is limited by access to energetic resources, then the main limiting factor for males is access to ovulating females. Males, then, must compete for access to females, and this sets up complex dynamics between males in different types of grouping patterns. This unit looks at the ecology of male relationships and the social dynamics among males in different societies and grouping patterns. We explore the nature of male competition, the dynamics of rank acquisition and maintenance, and the fates of males who transfer between different groups.

Objectives

When you have completed Unit 7, you should be able to

1. explain what the main limiting resource is for males and why it is important to understanding competition among males.
2. explain why males of some primate species involve infants during aggressive interactions.
3. describe the social dynamics among males in patrilocal societies during the different stages of their life histories.
4. describe the social dynamics among males who disperse from their natal group during the different stages of their life histories.
5. explain the concepts of rank and dominance, the various ways it is acquired and maintained among males, and its proposed function in males.
6. describe the dynamics among males that are peripheral to a breeding group (e.g., males in an all-male group or who are unattached).
7. discuss the concept and proposed function(s) of male baboon “friendships” with female baboons.

Viewing Assignments

In preparation for the final examination, you must watch at least four videos of the five options listed in Units 6 through 11. Each unit gives you two video options, so that by the end of Unit 11 you should have watched four videos from these five options:

The New Chimpanzees or The Nut-Cracking Chimpanzees of Tai Forest
Family of Chimps or Primate/Human Interaction
Can Chimpanzees Talk or Ape Genius
Gremlins: Faces in the Forest or 3 Monkeys
The Rain Forest Imperative or Gorillas in the Midst of Man

It does not matter the order in which you watch your video options, but the viewing assignments for each unit offer you a guide. Remember, completing a viewing assignment differs from watching a video for pleasure. You should consider watching each video twice: once to get an overview, and once to make notes. Study questions or instructions for viewing are supplied for each video; be certain that you read them over before you begin watching, and keep them in mind as you complete the assignment and make your notes.

Unit 7 Viewing Assignment

Watch one of the videos listed below.

Zeller, Anne
1997  Primate/Human Interaction. 11 min. Watertown, MA:
Documentary Educational Resources.

This short video presents many examples of visual communication and body language used by primates in their interactions with humans. It can also serve as a basis for a discussion on the general relationships between humans and primates from a conservation perspective.

If you choose this video, then in preparation for the examination, be certain that you can answer the questions given below.

1. What behaviours suggest nervousness and ambivalence among baboons?
2. How do blue monkeys use the environment to reduce anxiety?
3. What are eyelid flickers, and what is their function?
4. What typical behaviours between humans and primates are more likely to result in flight or aggression on the part of the primates?
5. What is the best way to communicate amiable intentions towards primates? Why?

or

Haanstra, Bert
n.d.  Family of Chimps. New York: Filmmakers Library.

This video features the best known group of captive chimpanzees in the world. All features of chimpanzee social behaviour are presented, but the focus is on group interaction, social learning, and problem solving abilities.

If you choose this video, then in preparation for the examination, be certain that you can answer the questions given below.

1. Provide examples of variations in behaviour between group members.
2. Provide examples of social learning.
3. What kinds of tools are used, and what are they used for?
4. Provide examples of problem solving.
5. Describe infant development and the role of alloparenting.
6. Describe individual rearing styles of play behaviour and mothering.
7. What is a play face? How is it done?
8. What behaviours indicate close bonds between males?
9. How and why do males cooperate with each other?
10. Provide examples of body language among chimpanzees.

Alternative Reading Assignment

If you cannot complete the viewing assignment before the final examination, you must do the alternative reading assignment instead. You may combine the reading with viewing assignments so that you have a total of four video and reading combinations. For example, you can watch three videos and do one reading assignment for the final examination. Or, if you cannot watch any videos, then you must complete four reading assignments from the five options presented in Units 6-11. The reading materials can be ordered from the library. Be sure you can answer the questions below each assignment.

Unit 7 Alternative Reading Assignment

If you cannot complete the viewing assignments, you must do the alternative assignment below.

Smuts, Barbara
1998  Chapter Five, What Are Friends For? In The Primate
Anthology: Essays on Primate Behavior, Ecology, and
Conservation from Natural History. Ciochon, Russell L. and
Richard A. Nisbett, eds. Pp. 36-43. Upper Saddle River, NJ:
Prentice-Hall.

In preparation for the examination, be sure that you can answer the questions below.

1. In this essay, author and baboon researcher Barbara Smuts is interested in why female baboons mate with particular males during their short periods of estrus. What aspects of baboon behaviour does Smuts focus on to give her insights into why females prefer certain males during these relatively short (but crucial) periods of their lives?
2. How does Smuts define heterosexual “friendships” in baboons? What does she use to measure this particular social bond?
3. What factors seemed to influence which male and female baboons paired up in friendships?
4. Which males are more likely to have female “friends”?
5. What does “presenting” (placing rump in front of the face of another individual) mean in baboon society? Is it a sexual invitation?
6. What are the two main advantages for females in having male “friends”?
7. What is the main advantage for a male in having a female friend?
8. How can Smuts’ research on baboon friendships inform our theories concerning the evolution of relationships between early human males and females?