Book contents
- Frontmatter
- Contents
- List of contributors
- Foreword
- Preface
- Part I Reproductive skew theory
- Part II Testing assumptions and predictions of skew models
- 3 Reproductive skew in female-dominated mammalian societies
- 4 The effects of heterogeneous regimes on reproductive skew in eutherian mammals
- 5 Social skew as a measure of the costs and benefits of group living in marmots
- 6 Explaining variation in reproductive skew among male langurs: effects of future mating prospects and ecological factors
- 7 The causes and consequences of reproductive skew in male primates
- 8 Sociality and reproductive skew in horses and zebras
- 9 Reproductive skew in avian societies
- 10 Reproductive skew in cooperative fish groups: virtue and limitations of alternative modeling approaches
- 11 Reproductive skew in primitively eusocial wasps: how useful are current models?
- Part III Resolving reproductive conflicts: behavioral and physiological mechanisms
- Part IV Future directions
- Taxonomic index
- Subject index
8 - Sociality and reproductive skew in horses and zebras
from Part II - Testing assumptions and predictions of skew models
Published online by Cambridge University Press: 02 February 2010
- Frontmatter
- Contents
- List of contributors
- Foreword
- Preface
- Part I Reproductive skew theory
- Part II Testing assumptions and predictions of skew models
- 3 Reproductive skew in female-dominated mammalian societies
- 4 The effects of heterogeneous regimes on reproductive skew in eutherian mammals
- 5 Social skew as a measure of the costs and benefits of group living in marmots
- 6 Explaining variation in reproductive skew among male langurs: effects of future mating prospects and ecological factors
- 7 The causes and consequences of reproductive skew in male primates
- 8 Sociality and reproductive skew in horses and zebras
- 9 Reproductive skew in avian societies
- 10 Reproductive skew in cooperative fish groups: virtue and limitations of alternative modeling approaches
- 11 Reproductive skew in primitively eusocial wasps: how useful are current models?
- Part III Resolving reproductive conflicts: behavioral and physiological mechanisms
- Part IV Future directions
- Taxonomic index
- Subject index
Summary
Summary
The outcome of competition for resources or mates often leads to individual differences in reproductive success. In populations of equids, such as those of horses and zebras, skewed distributions of reproduction emerge because a limited number of individuals achieve disproportionate gains. For both sexes, skew results fromdifferences in rank, age, and degree of social stability, although skew is generally greater formales than for females. Adultmale horses and zebras typically establish “harem” groups by bonding with a number of mature females. Although the number of females that dominants bond with can be quite variable, potentially high levels of skew are rarely reached because subordinate males adopt alternative mating tactics that exact concessions from partners, whether they are dominant stallions or other subordinates. Successful breeding females also rely on support from subordinates to minimize feeding competition by keeping group size small, and this, too, reduces skew among females. The conflict of interest between the sexes arising over differences in optimal group size, along with the tendency for females to leave groups when sexually harassed, induces, but limits, the aggression that males direct towards females. Thus female concessions can shape both female and male levels of skew, but they also can be modulated bymale behavior. Thus it appears that for equids the level of skewthat emerges depends on key phenotypic traits and how their distribution among individuals constrains reproduction, as well as on how social relationships within and between the sexes affect the ability of a small number of individuals to monopolize resources involved in reproduction.
Inequality is a pervasive feature of virtually all societies, as is the attempt by the disadvantaged to attenuate it.
- Type
- Chapter
- Information
- Reproductive Skew in VertebratesProximate and Ultimate Causes, pp. 196 - 226Publisher: Cambridge University PressPrint publication year: 2009
- 24
- Cited by