Elephants and Savanna Woodland Ecosystems E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Serie: Conservation Science and Practice
• Sprache: Englisch

Seitenzahl: 604

Veröffentlichungsjahr: 2014

Beschreibung

During the nineteenth century, ivory hunting caused a substantial decrease of elephant numbers in southern Africa. Soon after that, populations of many other large and medium-sized herbivores went into steep decline due to the rinderpest pandemic in the 1890s. These two events provided an opportunity for woodland establishment in areas previously intensively utilized by elephants and other herbivores. The return of elephants to currently protected areas of their former range has greatly influenced vegetation locally and the resulting potential negative effects on biodiversity are causing concern among stakeholders, managers, and scientists.

This book focuses on the ecological effects of the increasing elephant population in northern Botswana, presenting the importance of the elephants for the heterogeneity of the system, and showing that elephant ecology involves much wider spatiotemporal scales than was previously thought. Drawing on the results of their research, the authors discuss elephant-caused effects on vegetation in nutrient-rich and nutrient-poor savannas, and the potential competition between elephants on the one hand and browsers and mixed feeders on the other.

Ultimately this text provides a comprehensive review of ecological processes in African savannas, covering long-term ecosystem changes and human-wildlife conflicts. It summarises new knowledge on the ecology of the sub-humid African savanna ecosystems to advance the general functional understanding of savanna ecosystems across moisture and nutrient gradients.

Leseprobe

Table of Contents

Cover

Conservation Science and Practice Series

Previously published

Title Page

Copyright

List of Contributors

Foreword

Preface

Part I: The Chobe Ecosystems

Chapter 1: Introduction

References

Chapter 2: The Chobe Environment

Geomorphology

Soils

Climate

Flora and vegetation in the Chobe savanna

The mammal community

Human impact

Closing remarks

References

Chapter 3: Elephant-Mediated Ecosystem Processes in Kalahari-Sand Woodlands

Large herbivore biomass density and the contribution of elephants

How can a dystrophic ecosystem support so many elephants?

An elephant ecosystem

Interactions between keystone and foundation species maintain regional biodiversity

References

Part II: The Substrate

Chapter 4: Historical Changes of Vegetation in the Chobe Area

Vegetation in the Chobe area before the decline in elephants

Elephants, germs, livestock and logging

Vegetation changes on the alluvium and on the sand

Elephants and the Chobe woodlands

References

Chapter 5: Vegetation: Between Soils and Herbivores

Habitat types

Plant communities, species diversity and structure of vegetation

Abiotic and biotic variables related to the present vegetation

Life-form and species distribution

Seed-bank of woody species

Concluding remarks

References

Part III: The Agent

Chapter 6: Guns, Ivory and Disease: Past Influences on the Present Status of Botswana's Elephants and their Habitats

Introduction

Pre- and post-colonial hunting of elephants in southern Africa

Disease and ecological transformation: the rinderpest panzootic arrives in 1896

Recovery of Botswana's elephant population in the 20th century

Overview

References

Chapter 7: The Chobe Elephants: One Species, Two Niches

Sexual size-dimorphism and social organization

Sex differences in the use of plant parts

Browsing height stratification

Sex differences in the use of food patches

Sexual segregation at the habitat scale

Implications for management and further research

References

Chapter 8: Surface Water and Elephant Ecology: Lessons from a Waterhole-Driven Ecosystem, Hwange National Park, Zimbabwe

A brief description of Hwange National Park

Movement patterns reveal the dry-season trade-off between foraging and drinking

Evidence that water defines key-resource areas: population-level processes

Beyond water, habitats and social interactions

Surface-water driven management of elephants and savanna ecosystems

Acknowledgements

References

Part IV: Controllers

Chapter 9: Soil as Controller of and Responder to Elephant Activity

The soils

Soil as a controller of elephant activities and impact

Soil controls the vegetation

Mammal communities and soil

Soil as a responder to elephant activities

Large herbivores and fire

References

Chapter 10: Impala as Controllers of Elephant-Driven Change within a Savanna Ecosystem

Introduction

Impala and seedlings

Seedling predation across eastern and southern African savannas

Impala prevent woodland regeneration

A guild-based approach to predicting the effects of ungulates on tree establishment

Cascading effects of an ecosystem controller

References

Chapter 11: Buffalo and Elephants: Competition and Facilitation in the Dry Season on the Chobe Floodplain

Introduction

Spatial and temporal overlap between elephant and buffalo in Chobe

Interference competition

Buffalo as a controller of elephant grazing

References

Part V: Responders

Chapter 12: Plant–Herbivore Interactions

A partially migratory system

Plant characteristics vary with resource availability and herbivory

Large herbivores feed selectively in response to plant traits

Plant responses to large herbivores

Herbivore responses to plant responses

Interactions between elephants, plants and ungulates

References

Chapter 13: Elephants and the Grazing and Browsing Guilds

How this chapter was compiled

Grazing and browsing ungulates in the Chobe environment

Historical changes in abundance and foraging of some grazing and browsing ungulates

The grazing, the mixed feeding and the browsing guilds

Elephants and the grazing and the browsing guild

References

Chapter 14: Cascading Effects on Smaller Mammals and Gallinaceous Birds of Elephant Impacts on Vegetation Structure

Medium-sized mammals and gallinaceous birds: large-scale habitat selection and diversity

Gallinaceous birds: selection of cover within high-density habitats

Small mammals

Discussion

Conclusion

References

Chapter 15: The Chobe Riverfront Lion Population: A Large Predator as Responder to Elephant-Induced Habitat Heterogeneity

Introduction

Habitat heterogeneity and population regulation in carnivores

The lion riverfront population

Elephant impact and the lion riverfront population

Conclusion

References

Part VI: Elephants in Social-Ecological Systems

Chapter 16: Human Dimensions of Elephant Ecology

History of human-elephant conflict (HEC) and coexistence

Elephants as threats to humans and their crops

Management and mitigation of HEC

Humans as threats to elephants

Elephant macroeconomics – ivory and tourism

Elephant microeconomics – community-based conservation initiatives

Attitudes and conflicts

Conclusions and recommendations

References

Chapter 17: Elephants and Heterogeneity in Savanna Landscapes

Elephant drinking sites, transition zones, and population regulation

Available area, distance between waterpoints, and elephant overpopulation

Are elephants agents of landscape heterogeneity or homogeneity?

Conclusion

References

Index

Supplemental Images

End User License Agreement

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Guide

Cover

Table of Contents

Preface

Part I: The Chobe Ecosystems

Chapter 1: Introduction

List of Illustrations

Figure 1.1

Figure 2.1

Figure 2.2

Figure 2.3

Figure 3.1

Figure 4.1

Figure 4.2

Figure 5.1

Figure 5.2

Figure 6.1

Figure 6.2

Figure 6.3

Figure 7.1

Figure 7.2

Figure 8.1

Figure 8.2

Figure 8.3

Figure 9.1

Figure 9.2

Figure 10.1

Figure 10.2

Figure 10.3

Figure 10.4

Figure 12.1

Figure 12.2

Figure 14.1

Figure 15.1

Figure 15.2

Figure 15.3

Figure 15.4

List of Tables

Table 2.1

Table 2.2

Table 5.1

Table 7.1

Table 9.1

Table 9.2

Table 9.3

Table 11.1

Table 11.2

Table 11.3

Table 11.4

Table 13.1

Table 13.2

Table 14.1

Table 14.2

Table 14.3

Table 14.4

Table 14.5

Table 14.6

Table 15.1

Table 15.2

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Elephants and Savanna Woodland Ecosystems

A Study from Chobe National Park, Botswana

Edited by

Christina Skarpe, Johan T. du Toit and Stein R. Moe

This edition first published 2014 © 2014 by John Wiley & Sons, Ltd

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Library of Congress Cataloging-in-Publication Data

Elephants and savanna woodland ecosystems : a study from Chobe National Park, Botswana / edited by Christina Skarpe, Johan T. du Toit and Stein R. Moe.

pages cm

Includes bibliographical references and index.

ISBN 978-0-470-67176-4 (cloth)

1. Elephants– Botswana– Chobe National Park. 2. Grassland ecology– Botswana– Chobe National Park. 3. Chobe National Park (Botswana) I. Skarpe, Christina, 1946- editor of compilation. II. Du Toit, Johan T., editor of compilation. III. Moe, Stein R., 1960- editor of compilation.

QL737.P98E443 2014

599.67096883– dc23

2013046029

A catalogue record for this book is available from the British Library.

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Cover image: Front cover: Elephants Loxodonta africana browsing on Croton megalobotrys.

Photo: Stein R. Moe.

Back cover: Alerted impala ram and a group of bull elephants, Mababe, Botswana.

Photo: Christina Skarpe.

Cover design by Design Deluxe

1 2014

List of Contributors

Per Arild Aarrestad

Norwegian Institute for Nature Research, Trondheim, Norway

Kathy A. Alexander

Department of Fisheries and Wildlife Conservation, Virginia Tech, Blacksburg, USA

Harry P. Andreassen

Faculty of Applied Ecology and Agricultural Sciences, Hedmark University College, Evenstad, Norway

Roger Bergström

Gropgränd 2A, Uppsala, Sweden

Simon Chamaillé-Jammes

Centre d'Ecologie Fonctionnelle et Evolutive, Montpellier, France

Kjell Danell

Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden

Johan T. du Toit

Department of Wildland Resources, Utah State University, Logan, Utah, USA

Øystein Flagstad

Norwegian Institute for Nature Research, Trondheim, Norway

Hervé Fritz

Laboratoire de Biométrie et Biologie Evolutive, Villeurbanne, France

Peter G.H. Frost

Science Support Service, Wanganui, New Zealand

Duncan J. Halley

Norwegian Institute for Nature Research, Trondheim, Norway

Håkan Hytteborn

Department of Plant Ecology and Evolution, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden

Department of Biology, Norwegian University of Science and Technology, Realfagbygget, Trondheim, Norway

Craig Jackson

Department of Biology, Norwegian University of Science and Technology, Realfagbygget, Trondheim, Norway

Thor Larsen

Norwegian University of Life Sciences, Aas, Norway

Hillary Madzikanda

Scientific Services, Zimbabwe Parks and Wildlife Management Authority, Causeway, Harare, Zimbabwe

Shimane Makhabu

Department of Basic Sciences, Botswana College of Agriculture, Gaborone, Botswana

Gaseitsiwe Masunga

Okavango Research Institute, University of Botswana, Maun, Botswana

Stein R. Moe

Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, Aas, Norway

Rapelang Mojaphoko

Ministry for Environment, Wildlife and Tourism, Botswana

Sekgowa S. Motsumi

Department of International Environment and Development Studies, Norwegian University of Life Sciences, Aas, Norway

Department of Environmental Affairs, Gaborone, Botswana

Gosiame Neo-Mahupeleng

Poso House, Gaborone, Botswana

Norman Owen-Smith

Centre for African Ecology, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa

A. H. M. Raihan Sarker

Department of Biology, Norwegian University of Science and Technology, Realfagbygget, Trondheim, Norway

Susan Ringrose

PO Box HA 65 HAK Maun, Botswana

Tuulikki Rooke

Research and Assessment Department, Swedish Environmental Protection Agency, Stockholm, Sweden

Eivin Røskaft

Department of Biology, Norwegian University of Science and Technology, Realfagbygget, Trondheim, Norway

Lucas Rutina

Okavango Research Institute, University of Botswana, Maun, Botswana

Thato B. Sejoe

Department of International Environment and Development Studies, Norwegian University of Life Sciences, Aas, Norway

P.O. Box 1826, Gaborone, Botswana

Christina Skarpe

Faculty of Applied Ecology and Agricultural Sciences, Hedmark University College, Evenstad, Norway

Sigbjørn Stokke

Norwegian Institute for Nature Research, Trondheim, Norway

Jon E. Swenson

Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, Aas, Norway

Cyril Taolo

Department of Wildlife and National Parks, Gaborone, Botswana

Marion Valeix

Laboratoire de Biométrie et Biologie Evolutive, Villeurbanne, France

Mark E. Vandewalle

CARACAL, Kasane, Botswana

Märtha Wallgren

Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, Uppsala, Sweden

Per Wegge

Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, Aas, Norway

Foreword

Norman Owen-Smith

Centre for African Ecology, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, South Africa

After a long journey through the dry Kalahari sand woodlands stretching over northern Botswana, a spectacular sight confronts one on arrival at the Chobe River. The emerald landscape of meadows and water on the associated floodplain is thronged by elephants, buffaloes and hippos, alongside numerous smaller ungulates and birds. This is a prime example of a megaherbivore-dominated ecosystem, lacking only the rhinos that were once also there. However, the very largest of these herbivores has been disrupting the structure and diversity of the riparian woodland, to the consternation of wildlife managers, tourist operators and visitors. The Chobe River front has attained notoriety for the woodland devastation wrought by the elephant concentrations there. Gaunt trunks of dead trees stand amongst battered shrubs above a sparse herbaceous cover. Should not something be done about the elephants to rectify this situation? Along with Tsavo National Park in Kenya, the state of woodland destruction at Chobe is commonly invoked as justification for culling elephants to alleviate the vegetation transformation and its ramifications for biodiversity.

This was the context for the BONIC project, established as an institutional collaboration involving the Norwegian Institute for Nature Research, the Norwegian University of Life Sciences, and the Botswana Department of Wildlife and National Parks. Its aim was to advance local capacity to address this and other problems in the management of Botswana's rich wildlife resource, through research and training. The expectation was that participating wildlife ecologists from the far north, untainted by the polarised standpoints about the management of elephants that prevail within African countries, would be openly receptive to the prospect of culling elephants if ecologically justified. After all, Norway has persisted in harvesting of whales, despite international criticism. The crucial research needed was to interpret the impacts that elephants were obviously having on riparian woodlands within the context of other ecosystem components and processes. Hence studies were focused not merely on the elephants, but also on their effects on soil properties and tree regeneration, the consequences of woodland transformation for other browsers and grazers, and ramifying influences on predators, small mammals and even some groups of birds. The chapters of this book document the findings from this comprehensive suite of studies, summarising or elaborating numerous papers that have appeared in scientific journals as well as the contents of several unpublished theses.

Surprisingly to some, these studies did not find adverse consequences of the obvious elephant impacts on vegetation for any animal species, apart from bushbuck, which have declined in abundance from earlier times when the bush cover was much thicker. The stumbling block for restoration of the woodlands lies in the high local abundance of impala, a much smaller herbivore that is a mixed grazer-browser. Exclosure plots demonstrated that their browsing of tree seedlings is so thorough that very few of these seedlings have much chance of escaping towards tree height. Moreover, rather than competing for browse, elephants favour different woody species from those utilized by browsing ruminants. This finding reinforces the suggestion that megaherbivore extinctions largely through human hunting had negative consequences for post-Pleistocene large mammal diversity worldwide (Owen-Smith, 1987, 1989). The disturbing impacts that mammoths, mastodons and other very large herbivores must have had on woodlands and forests would have brought more browse within the reach of smaller browsers, while increasing the extent of meadows for grazers. Hence the largest herbivores can facilitate the coexistence of smaller species through these mechanisms, rather than competing with them for shared vegetation resources.

Nevertheless, the extent of the woodland destruction along the Chobe River front is regrettable negative scenically. However, happenings in the more distant past have probably contributed to this situation. After the extirpation of the elephants, browsing antelope became decimated by rinderpest, allowing unfettered growth by trees. Are the Chobe woodlands merely reverting to the messy state that had prevailed when herbivores from elephants size down had all been hugely abundant? But expanded human pressures are an exacerbating influence, funnelling elephants into a narrow section of river front between Kasane town and villages within the Kachikau enclave, and blocking movements across the international border into Namibia.

Fundamental questions remain about how riparian woodlands can withstand the elephant concentrations that develop along Africa's “pristine” rivers during the dry season. Seasonal elephant densities even greater than those near the Chobe River have become established along the Linyanti River to the west, following the drying of the Savuti Channel and other water sources in the interior. Will the vegetation transformation there progress towards the state prevalent along the Chobe? Or be averted by the wider scope that elephants have for movement in the Linyanti region? Research is in progress to assess this trend and where it might eventually lead.

Elephants and their impacts on trees have drawn most of my attention. But the chapters in this book encompassing broader ecosystem ecology will be more widely valuable as a counterpoint to the renowned studies undertaken in the grassland ecosystem prevalent in the Serengeti region of Tanzania. Most of Africa is very different in aspect from Serengeti, having vast areas of fairly well wooded savanna occupying nutrient deficient soils of granitic or Aeolian origin. In these parts the very largest grazers and browsers assume dominance of the herbivore biomass rather than the “plains game” typical of the East African plateau. Botswana is an amazingly diverse country, with dry savanna woodlands juxtaposed with the wetlands of the Okavango Delta and abutting Kalahari semi-desert in the south. Interspersed are localities where the concentration of herbivores and predators rival those in the Serengeti ecosystem. There are huge challenges in managing Botswana's rich wildlife legacy, not least because of the continuing expansion of the elephant population, approaching 150,000 animals at the time of writing. A major contribution of the BONIC programme was its fostering of local wildlife scientists equipped with the qualifications to take responsibility for this custodianship. Regional planning is well advanced for Chobe National Park to become a component of the vast Kavango-Zambezi Transfrontier Conservation Area stretching from Botswana through adjoining parts of Namibia, Zimbabwe, Zambia and Angola. The findings from the BONIC studies will help inform this ambitious development in its aim of promoting the coexistence of people and wildlife.

References

Owen Smith, N. (1987) Late Pleistocene extinctions: the pivotal role of megaherbivores.

Paleobiology

13

, 351–362.

Owen Smith, N. (1989) Megafaunal extinctions: the conservation message from 11 000 years BP.

Conservation Biology

3

, 405–412.

Preface

The common image of an African savanna, held by people living far from savanna environments, is a landscape of short-cropped grass and scattered Acacia trees that is teeming with medium-sized grazing ungulates such as plains zebra, Equus quagga, and blue wildebeest, Connochaetes taurinus. This is an image based largely on the Serengeti-Mara ecosystem in Tanzania and Kenya, well known from extensive popular science publications, films and TV programs, as well as seminal scientific publications. The woodland savannas of Chobe National Park in Botswana, the focus for this book, present a very different image. Whereas mean annual rainfall is about the same in large areas of Serengeti and Chobe, most other ecological conditions are different. Instead of the nutrient-rich volcanic soils of the Serengeti savannas, the Chobe woodlands grow on nutrient-deficient Kalahari sand and instead of scattered fine-leafed Acacia trees, the Chobe woodlands consist primarily of large, broad-leafed trees. The abundant medium-sized grazers in the Serengeti are replaced in the Chobe woodlands by a dominance of larger-bodied species such as African buffalo, Syncerus caffer, and elephant, Loxodonta africana, with more than half the herbivore biomass in Chobe National Park contributed by elephants alone.

Elephants were virtually exterminated from the Chobe ecosystem by an intense bout of commercial ivory hunting in the late 19th century. Over the following decades, woodlands established on the previously open narrow strip with alluvial soil close to the Chobe River. These woodlands were different from those on the Kalahari sand in most of the Chobe National Park. Once the elephant population eventually began recovering, elephants killed the trees in these newly established woodlands by debarking them, and since the 1960s managers and conservationists have been concerned about the destruction of the scenic woodlands along the Chobe River. This ‘Chobe elephant problem’ was the rationale for the Botswana–Norway Institutional Cooperation Project (BONIC), a research and capacity building project run in cooperation between the Botswana Department of Wildlife and National Parks (DWNP) and two Norwegian research institutions: the Norwegian Institute for Nature Research (NINA) and the Norwegian University for Life Sciences (UMB), with funding from the governments of Botswana and Norway. BONIC operated from 1997 to 2003 and encompassed studies on diverse aspects of the Chobe ecosystem, all with a focus on the ecological implications of the increasing elephant population. At the termination of the project, a workshop was held in Kasane, adjacent to the study area, over 13–15 March 2003 including about 50 people from DWNP, NINA, UMB, University of Botswana, some non-governmental organisations and three specially invited experts: Patrick Duncan, Norman Owen-Smith and Anthony R.E. Sinclair. The workshop resulted in the first compilation of preliminary results from the project in a volume of proceedings, edited by Mark Vandewalle and published by the Government Printer, Gaborone, Botswana in 2003. It was followed in 2004 by an overview article about the project in the journal AMBIO by C. Skarpe and 26 co-authors from the project.

The workshop in 2003 gave rise to the idea of an edited book drawing from the main results from the project. First, over the ten years following the completion of the project, the results of various sub-projects were written up as graduate theses and peer-reviewed journal publications. Finally, this book synthesizes the ecological research conducted under the auspices of BONIC. The book's aim is to present results from the project related to the effects of elephants on ecosystem dynamics and heterogeneity, and finally to discuss the extent to which there is an ‘elephant problem’ in Chobe. The book compiles information from a nutrient-poor and elephant-rich savanna to allow comparison with other African savannas, for example: the nutrient-rich Serengeti-Mara ecosystem as presented in the three books edited by A.R.E. Sinclair and colleagues (University of Chicago Press 1979, 1995, 2008); the Kruger National Park on mixed soil types, as described in the book edited by J.T. du Toit, K.H. Rogers and H.C. Biggs (Island Press 2003); the nutrient-poor and elephant-free Nylsvley savanna described by R.J. Scholes and B.H. Walker (Cambridge University Press, 1993).

Most studies in the BONIC project are included in this book, some constituting individual chapters. We refer as far as possible to published data from the project, although data from PhD and MSc theses are also referred to along with some previously unpublished data, which are included without references. Four staff members from DWNP completed their PhD projects within BONIC and all of them contributed as authors to this book: Shimane W. Makhabu, Gaseitsiwe S. Masunga, Lucas P. Rutina and Cyril L. Taolo. Eight staff members from DWNP completed their MSc studies within BONIC: Kingsley M. Leu, Itani Mathumo, Thato B. Morule, David K. Mosugelo, Sekgowa S. Motsumi, Elsie T. Mvimi, Gosiame Neo-Mahupeleng and Claudia S. Zune. Their work has directly and indirectly contributed to this book.

Neither the BONIC project nor this book could have come into existence without DWNP, being the project leader, and the Ministry of Environment, Wildlife and Tourism of Botswana and their staff. Apart from staff members appearing as authors in the book, we particularly thank Jan Broekhuis, Joe Matlhare, Sedia Modise, Dan Mughogho, Bolt Othomile and Botshabelo Othusitse. Further, Thatayaone Dimakatso, Frederick Dipotso, Wilson Marokane, Moses Mari, Mpho Ramotadima, Ditshoswane Modise (now deceased), Zenzele Mpofu (now deceased), Lettie Sechele and many others helped as counterparts and field assistants in data collection and research. Abraham Modo (now deceased), then District Coordinator for Ngamiland, contributed by allowing his staff to participate in the project as field assistants.

The Norwegian Embassy in Gaborone provided valuable support to the project, and we are particularly indebted to Jan Arne Munkeby, who was the Norwegian Chargé d'Affaires at the time of project inception. Britt Hilde Kjølås, Embassy Secretary, also provided invaluable assistance during the initial phase of the project.

The chapters of this book were improved by the critical comments of independent expert reviewers and the following are thanked for their valuable contributions: George Batzli, Jane Carruthers, David H. M. Cumming, Hervé Fritz, Jacob R. Goheen, Ricardo Holdo, R. Norman Owen-Smith, Steward T.A. Pickett, Robert J. Scholes, Peter Scogings, Anthony R.E. Sinclair, Izak Smit, Marion Valeix and George Wittemyer. We sincerely thank the editing team at Wiley-Blackwell, particularly Ward Cooper, Kelvin Matthews and Carys Williams for encouraging and efficient collaboration as well as great patience. We further thank Ola Diserud and Andreas Brodén for contributions to Chapters 5 and 9, respectively; Marit Hjeljord for drawing many of the figures; and Lin Cassidy for drawing the map in Figure 1.3.

Finally, the entire text of this book was copyedited by Peter Frost who applied his writing skills, understanding of the English language, broad knowledge of African savannas and, above all, his meticulous professionalism, to substantially enhance the final product. For his valued contributions the editors owe Peter a large debt in gratitude.

References

Sinclair, A.R.E. & Northon-Griffiths, N. (1979)

Serengeti: Dynamics of an Ecosystem

. University of Chicago Press.

Scholes, R.J. & Walker, B.H. (1993)

An African Savanna: Synthesis of the Nylsvley Study

. Cambridge University Press.

Sinclair, A.R.E. & Arcese, P. (1995)

Serengeti II: Dynamics, Management, and Conservation of an Ecosystem

. University of Chicago Press.

du Toit, J.T., Rogers, K.H. & Biggs, H.G. (2003)

The Kruger Experience: Ecology and Management of Savanna Heterogeneity

. Island Press.

Sinclair, A.R.E., Packer, C., Mduma, S.A.R. & Fryxell, J.M. (Eds.) (2008)

Serengeti III: Human Impacts on Ecosystem Dynamics

. University of Chicago Press.

Part I

The Chobe Ecosystems