Decline and Recovery of the Island Fox: A Case Study for Population Recovery (Ecology, Biodiversity and Conservation)

Title......Page 7
Copyright......Page 8
Dedication......Page 9
Contents......Page 11
Foreword......Page 14
Acknowledgments......Page 16
1 Introduction......Page 19
2.1 Description......Page 23
2.2 Dwarfism and the island syndrome......Page 25
2.3.1 Colonization of the islands......Page 26
2.3.2 Rapid evolution......Page 29
2.4 Island foxes in the paleoenvironment......Page 30
2.5 The peculiar genetic status of the island fox......Page 31
2.6 Genetic management of captive island foxes......Page 33
2.7 Future of wild populations......Page 38
3 Social structure, reproduction, mortality and survivorship, and population dynamics......Page 39
3.1.1 Social structure......Page 40
3.1.2 Reproduction......Page 41
3.2 Mortality and survivorship......Page 42
3.3.1 Population abundance......Page 45
3.3.2 Population density......Page 47
3.4.2 Disease......Page 48
3.4.3 Density dependence......Page 49
3.5 Modeling island fox population dynamics......Page 50
3.6 Summary......Page 51
4.1.1 Animal prey......Page 52
4.1.2 Plants......Page 54
4.1.3 Feeding behavior......Page 55
4.2 Dispersal and travel......Page 56
4.3 Home range......Page 57
4.4 Habitat use......Page 58
4.5 Activity patterns......Page 59
4.6 Summary......Page 60
5.1 Detecting change......Page 61
5.2 Determining the cause......Page 65
5.3 Golden eagle colonization of the northern islands......Page 68
5.4 The vulnerability of island foxes to diurnal aerial predators......Page 74
6.1 Golden eagle removal......Page 76
6.1.1 Approach and methods......Page 77
6.1.2 Lethal removal......Page 80
6.2.1 Removal of feral pigs from Santa Cruz Island......Page 84
6.2.2 Removal of mule deer from Santa Rosa Island......Page 86
6.2.3 Reintroduction of bald eagles......Page 87
6.3 Summary......Page 89
7.1 Declining populations......Page 91
7.3 Was disease the cause of the decline?......Page 93
7.4 Recommendations for population recovery......Page 94
7.5 Testing CDV vaccine......Page 95
8.1 Captive breeding efforts on the northern islands......Page 99
8.2.1 Facility design and construction: San Miguel and Santa Rosa Islands......Page 100
8.2.2 Facility design and construction: Santa Cruz Island......Page 103
8.2.3 Facility design and construction: Santa Catalina Island......Page 104
8.2.4 Selecting the captive population: Santa Catalina......Page 106
8.2.5 Nutrition......Page 108
8.2.6 Escapees and perimeter fences......Page 109
8.3 Demographic and genetic objectives of captive breeding......Page 110
8.4 Low reproductive success......Page 111
8.4.1 Stress and behavior......Page 113
8.5 Summary......Page 116
9.1.1 Methods......Page 118
9.1.2 Results......Page 119
9.2.1 Methods......Page 120
9.3 Reintroduction program on the northern islands......Page 121
9.3.1 Methods......Page 124
9.3.2 Results......Page 125
9.4 Success of reintroduction......Page 129
9.5 Summary......Page 131
10 Reproductive biology, by Cheryl Asa......Page 133
10.1 Reproductive cycles......Page 134
10.2 Captive breeding......Page 135
10.2.1 Hormone studies......Page 137
10.2.2 Investigation of possible causes of reproductive failure......Page 138
10.3 Results of the monitoring study......Page 141
10.4 Summary......Page 145
11 Diseases of island foxes, by Linda Munson......Page 147
11.1 Disease in island populations......Page 148
11.2 Could viral disease explain the population declines?......Page 149
11.3 Do other viruses infect island foxes?......Page 151
11.5 Parasites infecting island foxes......Page 152
11.6 Non-infectious diseases in island foxes......Page 156
11.7 Genetic diversity versus disease resistance......Page 158
11.8 Disease as a cause of death......Page 159
11.9 Overall health of the island fox populations......Page 160
12.1 Public advocacy......Page 162
12.2.1 Mainland exhibits......Page 164
12.2.3 Species management......Page 165
12.2.4 Future role for mainland populations......Page 166
12.3 Tachi and Finnegan......Page 167
12.5 Summary......Page 170
13.1 Stakeholders and recovery......Page 172
13.2 A model for management: the Island Fox Conservation Working Group......Page 174
13.3 Listing the island fox as endangered......Page 176
13.4.1 Permitting and USFWS oversight......Page 177
13.4.2 Recovery team and recovery plan......Page 178
13.5 The benefits and challenges of ESA listing......Page 181
13.6 Conclusion......Page 183
14.2 Background......Page 185
14.3.1 Deer mice......Page 187
14.3.2 Landbirds......Page 189
14.3.3 Black rats......Page 191
14.4.1 Spotted skunks......Page 192
14.4.2 Intraguild predation response......Page 193
14.5 Island communities without foxes......Page 194
14.6 Implications for research and management......Page 195
15.1 Status......Page 198
15.2 Future......Page 199
References......Page 203
Index......Page 225