Unit 5
Sociosexual Behaviour
and Dominance Hierarchies

In this unit, we review two areas of primate behaviour that have caused much discussion among primatologists over the last three decades. We first look at the variation of sociosexual behaviours, and their ecological and social correlates. We continue with a discussion of the hotly debated concept of dominance as a useful parameter for describing and predicting social relations within and between sexes. We conclude this section with a discussion of the ecological correlates of dominance, and the relationship between sociosexual behaviour, dominance, and reproductive strategies.

Objectives

When you have completed Unit 5, you should be able to

1. enumerate and describe the different biological and social components of sociosexual behaviour.
2. describe the variations in sociosexual behaviour found among primates.
3. describe the variations in male and female roles in sociosexual behaviour.
4. explain the relationship between the biological and social aspects of sexual behaviour and ecological variables.
5. explain the relationship between aggression and dominance.
6. explain the functions of dominance.
7. describe the different methods used to measure dominance.
8. describe the different ways males and females obtain their dominance rank.
9. explain the relationship between ecological variables and dominance hierarchies.

Viewing Assignment

If you wish to complete your next viewing assignment now, you may choose any of the videos listed in Units 2 or 3, or the video listed below. Note that you must have completed three viewing assignments or three alternative reading assignments before you take the midterm examination.

Zeller, Anne

1997 Sifakas of Madagascar. Watertown, MA: Documentary Educational Resources.

This video is a comparative study of two sifaka species of Madagascar. The detailed information on behaviour allows an understanding of the adaptive strategies of two closely related species. Particular emphasis is given to the diet, physical characteristics, and unusual form of locomotion.

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

1. What two species are presented in this video?
2. What distinguishing physical characteristics do these species possess?
3. What types of social groups do they form?
4. What type of environment do they inhabit?
5. How does diet change between seasons?
6. How is the body used to communicate? Provide examples.
7. What is the function of the caecum?
8. How and why is scent marking used in these species?
9. What types of affiliative behaviours are common in these species?
10. What is the mode of locomotion on the ground and why does it differ from the mode of locomotion in trees?

Note: Once you have completed the viewing assignment to your satisfaction, please return the video to the Athabasca University Library as soon as possible: the number of copies is limited, and other students will need it.