Decline and Recovery of the Island Fox: A Case Study for Population Recovery

by Timothy J. Coonan , Catherin A. Schwemm , David K. Garcelon

• ISBN13: 9780521715102
• ISBN10: 0521715105
• Format: Paperback
• Copyright: 2010-08-23
• Publisher: Cambridge University Press

Summary

Native only to the California Channel Islands, the island fox is the smallest canid in North America. Populations on four of the islands were threatened to extinction in the 1990s due to human-mediated predation and disease. This is the first account of the natural history and ecology of the island fox, illustrating both the vulnerability of island ecosystems and the efficacy of cooperative conservation measures. It explains in detail the intense conservation actions required to recover fox populations, such as captive breeding and reintroduction, and large-scale ecosystem manipulation. These actions were successful due in large part to extraordinary collaboration among the scientists, managers and public advocates involved in the recovery effort. The book also examines the role of some aspects of island fox biology, characteristic of the 'island syndrome', in facilitating their recovery, including high productivity and an apparent adaptation to periodic genetic bottlenecks.

Author Biography

Timothy J. Coonan is a US National Park Service Biologist at Channel Islands National Park, California. He has led the park's island fox recovery program since 1999. Catherin A. Schwemm is an Ecologist for the US National Park Service in Flagstaff, Arizona. In 1993 she began the island fox monitoring program for Channel Islands National Park, California, and she has been a member of the Island fox Conservation Working Group since 1999. David K. Garcelon is President and Founder of the non-profit Institute for Wildlife Studies in Arcata, California. His research activities have included long-term work on population demography, captive breeding, movement patterns, disease exposure, and behavior.

Table of Contents

Foreword	p. xii
Acknowledgments	p. xiv
Introduction	p. 1
Evolution and genetics	p. 5
Description	p. 5
Dwarfism and the island syndrome	p. 7
Evolution of the island fox	p. 8
Island foxes in the paleoenvironment	p. 12
The peculiar generic status of the island fox	p. 13
Genetic management of captive island foxes	p. 15
Future of wild populations	p. 20
Social structure, reproduction, mortality and survivorship, and population dynamics	p. 21
Social organization and reproductive behavior	p. 22
Mortality and survivorship	p. 24
Population abundance and dynamics	p. 27
Factors affecting population dynamics	p. 30
Modeling island fox population dynamics	p. 32
Summary	p. 33
Food habits, habitat use, activity patterns, and dispersal	p. 34
Food habits	p. 34
Dispersal and travel	p. 38
Home range	p. 39
Habitat use	p. 40
Activity patterns	p. 41
Summary	p. 42
Golden eagles and the decline on the northern islands	p. 43
Detecting change	p. 43
Determining the cause	p. 47
Golden eagle colonization of the northern islands	p. 50
The vulnerability of island foxes to diurnal aerial predators	p. 56
Ecosystem recovery: Predators and prey on the northern Channel Islands	p. 58
Golden eagle removal	p. 58
Long-term ecosystem recovery actions	p. 66
Summary	p. 71
Disease and decline on Santa Catalina Island	p. 73
Declining populations	p. 73
Initial results	p. 75
Was disease the cause of the decline?	p. 75
Recommendations for population recovery	p. 76
Testing CDV vaccine	p. 77
Recovery actions: Captive breeding of island foxes	p. 81
Captive breeding efforts on the northern islands	p. 81
Methodology and techniques	p. 82
Demographic and genetic objectives of captive breeding	p. 92
Low reproductive success	p. 93
Summary	p. 98
Recovery actions: Reintroduction and translocation	p. 100
Translocation on Santa Catalina	p. 100
Reintroduction on Santa Catalina	p. 102
Reintroduction program on the northern islands	p. 103
Success of reintroduction	p. 111
Summary	p. 113
Reproductive biology, by Cheryl Asa	p. 115
Reproductive cycles	p. 116
Captive breeding	p. 117
Results of the monitoring study	p. 123
Summary	p. 127
Diseases of island foxes, by Linda Munson	p. 129
Disease in island populations	p. 130
Could viral disease explain the population declines?	p. 131
Do other viruses infect island foxes?	p. 133
Do non-viral pathogens infect island foxes?	p. 134
Parasites infecting island foxes	p. 134
Non-infectious diseases in island foxes	p. 138
Genetic diversity versus disease resistance	p. 140
Disease as a cause of death	p. 141
Overall health of the island fox populations	p. 142
Zoos, education, and public participation	p. 144
Public advocacy	p. 144
The role of zoos	p. 146
Tachi and Finnegan	p. 149
Environmental education	p. 152
Summary	p. 152
Managing recovery: Cooperative conservation, politics, and the Endangered Species Act	p. 154
Stakeholders and recovery	p. 154
A model for management: the Island Fox Conservation Working Group	p. 156
Listing the island fox as endangered	p. 158
Changes in island fox management due to listing	p. 159
The benefits and challenges of ESA listing	p. 163
Conclusion	p. 165
The ecological role of island foxes	p. 167
Introduction	p. 167
Background	p. 167
Prey response	p. 169
Competitors	p. 174
Island communities without foxes	p. 176
Implications for research and management	p. 177
Conclusion	p. 180
Status	p. 180
Future	p. 181
References	p. 185
Index	p. 207
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