This book aims to reconcile theoretical models of population dynamics with what is currently known about the population dynamics of large mammalian herbivores. It arose from a working group established at the National Center for Ecological Analysis and Synthesis at the University of California, Santa Barbara, to address the need for models that better accommodate environmental variability, especially for herbivores dependent on changing vegetation resources. The initial chapter reviews findings from definitive long-term studies of certain other ungulate populations, many based on individually identifiable animals. Other chapters cover climatic influences, emphasising temperate versus tropical contrasts, and demographic processes underlying population dynamics, more generally. There are new assessments of irruptive population dynamics, and of the consequences of landscape heterogeneity for herbivore populations. An initial review of candidate population models is followed up by a final chapter outlining how these models might be modified to better accommodate environmental variability.
The contents provide a foundation for resolving problems of diminishing large mammal populations in Africa, over-abundant ungulate populations elsewhere, and general consequences of global change for biodiversity conservation. This book will serve as a definitive outline of what is currently known about the population dynamics of large herbivores.
Norman Owen-Smith has a special interest in the behavioural and population ecology of large mammalian herbivores. After obtaining his PhD for a study of white rhinos through the University of Wisconsin, he held appointments at the universities of Pretoria and Zimbabwe before settling into a position at the University of the Witwatersrand, where he headed the Centre for African Ecology.
Contributors Preface 1 Definitive case studies Norman Owen-Smith and Jason P. Marshal 1.1 Red deer on Rum 1.2 Soay sheep on Hirta 1.3 Roe deer in France 1.4 Bighorn sheep in Alberta 1.5 Kudu in Kruger 1.6 Wildebeest in Serengeti 1.7 Moose on Isle Royale 1.8 Elk in North Yellowstone 1.9 Overview Acknowledgments References 2 The suite of population models Norman Owen-Smith 2.1 Models of density dependence 2.2 Autoregressive time-series models 2.3 Age- or stage-structured models 2.4 Trophic interaction models 2.5 Physiological or metaphysiological models 2.6 Models accommodating spatial structure 2.7 Individual-based models 2.8 Overview Acknowledgments References 3 Climatic influences: temperate-tropical contrasts Norman Owen-Smith 3.1 Temperate environments 3.2 Tropical and subtropical environments 3.3 Effects of predation and hunting 3.4 Overall assessment Acknowledgments References 4 Demographic processes: lessons from long-term, individual-based studies Jean-Michel Gaillard, Tim Coulson and Marco Festa-Bianchet 4.1 Life history of large herbivores: a brief review 4.2 Differential contributions of demographic parameters to population growth 4.3 Climatic variation, density-dependence,andindividual variability 4.4 Conclusions:howcanfutureanalysesof largeherbivoredemography deal with complex demographic processes? Acknowledgments References 5 Irruptive dynamics and vegetation interactions John E. Gross, Iain J. Gordon and Norman Owen-Smith 5.1 Models of herbivore-vegetation interactions 5.2 Examples of irruptive dynamics 5.3 Effects of irruptions on vegetation 5.4 Changing perspectives 5.5 Synthesis 5.6 Implications for conservation and management Acknowledgments References 6 How does landscape heterogeneity shape dynamics of large herbivore populations? N. Thompson Hobbs and Iain J. Gordon 6.1 What is spatial heterogeneity? 6.2 How does spatial heterogeneity influence ungulate population dynamics? 6.3 Mechanisms explaining the influence of spatial heterogeneity on population dynamics 6.4 Influences from high-quality resources 6.5 Influences from buffer resources 6.6 Global change and access to heterogeneity by large herbivores 6.7 Conclusions: the importance of spatial context for population dynamics Acknowledgments References 7 Towards an ecology of population dynamics Norman Owen-Smith 7.1 Phenomenological descriptors 7.2 Time series elaborations 7.3 Environmental structure 7.4 Population structure 7.5 Adaptive responses and environmental contexts 7.6 Summary and conclusions Acknowledgments References Index