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  • Ecology of Red Fox (Vulpes vulpes) in the Lassen Peak Region of California, USA

    by

    John D. Perrine

    Department of Environmental Science, Policy and Management University of California, Berkeley

    Fall 2005

  • Ecology of Red Fox (Vulpes vulpes) in the Lassen Peak Region of California, USA

    by

    John Dixon Perrine III

    B.S. (Vanderbilt University) 1991 M.S. (Miami University) 1995

    A dissertation submitted in partial satisfaction of the

    requirements for the degree of

    Doctor of Philosophy in

    Environmental Science, Policy and Management

    in the

    GRADUATE DIVISION

    of the

    UNIVERSITY OF CALIFORNIA, BERKELEY

    Committee in charge:

    Professor Reginald H. Barrett, Chair Professor Stephen R. Beissinger

    Professor James L. Patton

    Fall 2005

  • Ecology of Red Fox (Vulpes vulpes) in the Lassen Peak Region of California, USA

    © 2005

    by

    John Dixon Perrine III

  • Abstract

    Ecology of Red Fox (Vulpes vulpes)

    in the Lassen Peak Region of California, USA

    by

    John Dixon Perrine III

    Doctor of Philosophy in Environmental Science, Policy and Management

    University of California, Berkeley

    Professor Reginald H. Barrett, Chair

    The red fox population inhabiting California’s Cascade and Sierra Nevada

    mountains (Vulpes vulpes necator) is listed as a State Threatened species, but its

    management has been hindered by a lack of basic ecological information. I conducted a

    comprehensive study of the red foxes in the Lassen Peak region to quantify their local

    distribution, resource utilization, activity patterns, niche overlap with likely competitors

    and genetic affinity with other red fox populations. The population was restricted to the

    region’s highest elevations, occurring >1300 m and primarily within the western half of

    Lassen Volcanic National Park. Red fox detections at camera traps in summer were

    positively correlated with elevation, highway density and the detection of coyotes, and

    were negatively correlated with shrub and herbaceous cover; in winter, detections were

    positively correlated with elevation, highway density and mature closed-canopy forest

    cover. Their diet was predominantly mammals, especially rodents and mule deer

    (Odocoileus hemionus), supplemented by birds, insects and manzanita (Arctostaphylos

    nevadensis) berries as seasonally available. Lagomorphs were virtually absent from the

    1

  • fox diet. Collared red foxes (n = 5) had large seasonal home ranges (95% MCP; mean =

    2,564 ha in summer and 3,255 ha in winter). On average, summer locations were 479 m

    higher than winter locations. Their summer range is likely unsuitable in winter due to

    deep soft snow and the lack of lagomorphs, a critical winter food for many other red fox

    populations, and these factors may limit the Lassen red fox population. Marten (Martes

    americana) used the same habitat as the foxes but preyed upon smaller rodents and were

    more diurnal. Coyotes (Canis latrans) were nocturnal like the foxes but were generally

    at lower elevations and ate larger prey. The Lassen foxes all had the same mtDNA

    haplotype, which was the most common haplotype among historic V. v. necator

    specimens and was rare in the exotic fox populations from California’s lowlands.

    Ecological and genetic evidence indicates that the Lassen red foxes are the native,

    threatened V. v. necator, not exotic foxes dispersed from the lowlands. Additional

    research is necessary to locate additional mountain red fox populations in California and

    to identify the factors preventing their dispersal to the lowlands and vice versa.

    2

  • i TABLE OF CONTENTS

    Table of Contents..................................................................................................................i List of Tables.......................................................................................................................ii List of Figures.....................................................................................................................iv Acknowledgements.............................................................................................................vi Introduction..........................................................................................................................1 Chapter 1: Seasonal Food Habits of Red Fox, Coyote and Marten in the

    Lassen Peak Region of Northern California..................................................15 Chapter 2: Distribution and Habitat Associations of Red Fox, Coyote and Marten

    in the Lassen Peak Region as Indicated by Camera Trap Surveys................53 Chapter 3: Activity Patterns of Sympatric Red Fox, Coyote and Marten

    in the Lassen Peak Region...........................................................................109 Chapter 4: Home Range and Habitat Use of Radio-Collared

    Mountain Red Foxes....................................................................................131 Chapter 5: Red Fox Population Structure in California..................................................166 Conclusions: Niche Overlap Among Red Fox, Coyote and Marten in the

    Lassen Region..........................................................................................190

    Literature Cited................................................................................................................196 Appendix A: Measurements of Scats of Known Species Identity..................................215 Appendix B: TrailMaster Camera Protocol....................................................................217 Appendix C: Red Fox Locations and Home Ranges by Season.....................................221 Appendix D: Parasites of Lassen Red Fox.....................................................................233 Appendix E: Historical Taxonomy of California’s Mountain Red Foxes......................235

  • ii LIST OF TABLES

    Table 1: Field identity versus cytochrome-b identity of scats..........................................38 Table 2: Seasonal diet composition for Lassen red fox, coyote and marten.....................39 Table 3: Dietary niche overlap between pairs of Lassen carnivores................................42 Table 4: Seasonal dietary overlap among all three carnivores.........................................43 Table 5: Annual camera sampling effort in the Lassen region.........................................89 Table 6: CWHR communities represented in general cover types...................................89 Table 7: Variables used in the grid cell analyses..............................................................90 Table 8: Distribution of camera traps and carnivore detections by

    CWHR community type....................................................................................91 Table 9: Detection of red fox and marten at camera traps in varying cover types...........92 Table 10: Detection statistics for each target species.......................................................93 Table 11: Univariate analysis of landscape variables in 2.6 km² cells.............................94 Table 12: Pairwise Pearson correlations among cell-level variables................................97 Table 13: Parameter estimates and odds ratios for terms in the landscape-only

    model resulting from the stepwise logistic regression...................................100 Table 14: Comparative fit of models by species and season..........................................101 Table 15: Parameter estimates and odds ratios for the most parsimonious

    multivariate models for red fox and coyote...................................................103 Table 16: Pairwise species associations at cameras within grid cells

    where both species of the pair were detected.................................................104 Table 17: Number of telemetry fixes and monitoring dates for

    radio-collared Lassen red fox.........................................................................123 Table 18: Distribution of seasonal detections of carnivores at

    baited camera stations....................................................................................123

  • iii Table 19: Was the number of detections proportional to the amount

    of time in each diel period?............................................................................124 Table 20: Follow-up tests of whether species pairs were similarly

    distributed within diel periods.......................................................................125 Table 21: Physical measurements at first capture for Lassen red foxes.........................157 Table 22: Number of locations, by type, for each collared red fox................................158 Table 23: Seasonal locations and home range size per collared red fox........................159 Table 24: Dates for seasonal home ranges......................................................................160 Table 25: Selection of cover types by individual red fox in summer........