Foreword ix
Preface xi
1. The Most Striking Feature of These Islands 1
1.1 Reptiles and the Discovery of the Galápagos Islands 1
1.2 Early Encounters with Tortoises 3
1.3 “Turpining” 5
1.4 Endangered Reptiles 7
1.5 Famous Tortoises 7
1.6 Reptiles and the Origin of the Galápagos Islands 8
1.7 A Paradise for Reptiles 10
2. A Congenial Habitation 13
2.1 Reptiles and the Origin of the Galápagos Islands 13
2.2 Plate Tectonics and the Formation of the Galápagos Islands 16
2.3 The Age of the Galápagos Islands 19
2.4 Galápagos Land Revisited 21
3. Giant Tortoises: Chelonoidis 27
3.1 The Last of His Kind 27
3.2 A Tortoise by Any Other Name… 28
3.3 A Multiplicity of Species 35
3.3.1 Questions of Provenance 37
3.3.2 The California Academy of Sciences Expedition
and Problematic Species 42
3.4 Species or Subspecies? 47
3.5 Domes and Saddles 48
3.6 Natural History 54
3.6.1 Daily Routine 54
3.6.2 Diet 59
3.6.3 Seed Dispersal and Climate Change 62
3.6.4 Predators and Parasites 63
3.7 Reproduction 66
3.7.1 Mating 66
3.7.2 Hormonal Cycles 68
3.7.3 Nesting 71
3.7.4 Temperature-Dependent Sex Determination 72
3.7.5 Growth Rates, Age to Sexual Maturity, and Life Span 73
3.7.6 Reproductive Biology and Mutation Rate 76
3.8 Evolution and Colonization 77
3.8.1 Mainland Origins 77
3.8.2 Genetic Analysis 79
3.8.2.1 Early Attempts at Genetic Analysis 79
3.8.2.2 Modern Genetic Analysis 81
3.8.2.3 Tortoises of Santa Cruz 83
3.8.2.4 Tortoises of Volcán Wolf 86
3.8.2.5 Tortoises of Volcán Alcedo 87
3.8.2.6 Tortoises of Southern Isabela 88
3.8.3 Phylogeny 91
3.8.4 Patterns of Colonization 95
3.8.5 Giant Tortoises and Evolutionary Hot Spots 97
3.9 The Human Factor 97
3.9.1 Tortoises as Commodities 97
3.9.2 Feral Animals 103
3.9.3 Restoration of Tortoise Populations 104
3.9.3.1 The Pinzón Head-Starting Program 105
3.9.3.2 The Española Captive Breeding Program 108
3.9.3.3 Volcán Wolf and the Recovery of Pinta and Floreana Tortoises 114
3.9.3.4 Floreana Tortoises 116
3.9.4 The Rewilding of the Galápagos 118
3.9.5 Continuing Threats 120
Tortoise Update 125
4. Geckos: Phyllodactylus 127
4.1 The Endemic Species 127
4.2 Evolutionary Relationships 129
4.3 Natural History 134
4.4 Introduced Geckos 134
5. Galápagos Racer Snakes: Pseudalsophis 139
5.1 Recognizing Diversity 139
5.2 Evolutionary Relationships 146
5.3 Natural History 149
6. Afterword 153
6.1 Early Encounters 153
6.2 Changing Taxonomies 153
6.3 Life Histories 154
6.4 Evolution 154
6.5 Colonization 155
6.6 Conservation 156
6.7 Concluding Remarks 157
References 159
Index 179
