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
6 - Explaining variation in reproductive skew among male langurs: effects of future mating prospects and ecological factors
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 partitioning of reproduction in a group, or reproductive skew, is affected by multiple ecological, genetic, and population parameters. The ways in which these factors interact to determine reproductive skew have been formally modeled, but few attempts have been made to assess the utility of skew theory in advancing our understanding of primate social systems and observed levels of skew. In the study presented here, I demonstrate how reproductive skew among male Hanuman langurs (Semnopithecus entellus) can be calculated using paternity data. In contrast to expectations, skew was found to increase with the number of males in a group. In a further analysis, I estimated skew for 21 populations of Asian langurs and investigated the ecological and population factors influencing variation in this parameter. The results lend support to model predictions that future mating prospects, as measured in chances of individual survival and number of potential mates, can be a significant predictor of skew. Furthermore, increased population density positively affected skew, which may reflect ecological constraints on dispersal for subordinates. These results suggest that skew theory may offer a useful framework for understanding the effects of multiple factors determining variation in reproductive skew.
Introduction
One of the key aims of studies in evolutionary biology, behavioral ecology, and primatology is to analyze the factors influencing variation in individual fitness and associated behavioral traits (e.g. Clutton-Brock & Harvey 1979, Krebs & Davies 1993). The interactions between key genetic and ecological parameters and features of animal societies were formally modeled in the late 1970s in the pioneering work of Sandra Vehrencamp, who developed a model of the degree to which fitness can be biased among group members (Vehrencamp 1979, 1983a, 1983b).
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- Information
- Reproductive Skew in VertebratesProximate and Ultimate Causes, pp. 134 - 164Publisher: Cambridge University PressPrint publication year: 2009
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