National Park Service

**Channel Islands National Park**

***ISLAND FOX RECOVERY PROGRAM***

***2003 ANNUAL REPORT***

####### Technical Report 04-02

####### Timothy J. Coonan

**Keith A. Rutz**

**Kathryn McCurdy**

**David K. Garcelon**

**Brian C. Latta**

**Linda Munson**

**National Park Service**

**Channel Islands National Park**

**1901 Spinnaker Drive**

**Ventura, CA 93001**

**Voice: (805) 658-5776**

**Fax: (805) 658-5798**

**Email: tim_coonan@nps.gov**

**May 2004**

####### ACKNOWLEDGEMENTS

Island fox recovery at Channel Islands National Park has been a team
effort since emergency recovery actions began in 1999. It continues to
be so, and we thank the many people whose time, efforts and expertise
have kept the program going.

Our thanks go first to the island fox caretakers, who provide the daily
care and enriched environments for the foxes. Thanks to Susan Coppelli,
Pedro Chavarria, Geoff Cline, Melanie Coulter, Stephanie Provinski,
Rachel Wolstenholme, Ryan Rumelhart, Sara Krause, Zac Nelson, and Chris
Newman. Others have volunteered their time to caretake for the foxes.
For this we thank Ian and Marcella Williams, Tom Dore, Don, Susan and
Allie Morris, Ray and Lorrie Aichner, Lindsay Martin, and Wendy
Crawford.

Thanks to Erik Aschehoug, Scott Morrisson and Lotus Vermeer of The
Nature Conservancy for their support in island fox recovery actions on
Santa Cruz Island, including construction and staffing of the captive
breeding facilities on that island. Tim Jones, Brent Wilson, Dave Mills,
and Sam Spaulding have assisted the fox recovery effort on Santa Cruz
with their expertise in maintenance, island logistics, and cultural
resources management. Lyndal Laughrin of the UC Santa Cruz Island
Reserve has provided much-needed logistical support for fox recovery
efforts on that island.

Thanks to San Miguel Island manager Ian Williams, who continues to
assist in all phases of the program on San Miguel. Thanks to Cass
Bromley and Jeff Sikich of Santa Monica Mountain NRA, who successfully
brought the last wild fox on San Miguel into captivity. Thanks also to
Seth Riley for loaning them to us for a week.

We thank our project veterinarian, Mark Willett, for conducting
veterinary exams, and providing veterinary care to foxes. When
circumstances required immediate veterinary care, time and effort were
kindly donated by veterinarians Karl Hill and Winston Vickers.

We again thank director Rich Block of the Santa Barbara Zoo for making
the zoo an effective partner in island fox captive breeding at the Park.
Rich, along with General Curator Alan Varsik and Assistant Curator
Ingrid Russell, have kindly donated their staff's time for veterinary
and fox care on the islands, and we have learned much from their staff's
experience with captive island foxes. Thanks to Alan Varsik and Julia
Parker of the Zoo for maintaining the island fox studbook.

Thanks to Cheri Asa and Joan Bauman of the St. Louis Zoo for
reproductive monitoring of captive foxes. Genetic analysis of the
captive island fox populations was conducted by Melissa Gray; thanks
also to Kathy Ralls and Jonathon Ballou for their assistance.

Guidance for the program has been provided by members of the island fox
conservation working group and others, who have donated time and
expertise to program oversight. We thank Kathy Ralls, Cheri Asa, Marsha
Sovada, Linda Munson, Bob Wayne, Phil Miller, Devra Kleiman, Rosie
Woodroffe, Dave Graber, Peter Dratch, Colleen Lynch, Bob DeLong, Cathy
Schwemm, Lyndal Laughrin, Grace Smith, Dan Blumstein, Brian Smith, Paul
Collins, Nancy Thomas, Gary Roemer, Mark Willett, Alan Varsik, Ingrid
Russell, Julia Parker, and Melissa Gray.

Our thanks go to the dedicated raptor biologists of the Santa Cruz
Predatory Bird Research Group for their relentless efforts to trap and
remove golden eagles from the northern Channel Islands. We appreciate
the work of Dan Driscoll, Craig Himmelwright, Greg Doney, Nick Todd, and
Vince McGlinchey.

Thanks to Rhonda Brooks, the late Fred Rodriguez and Doretta Burgess for
once again effectively coordinating transportation to the islands. We
particularly appreciate the skills and efforts of the Park's boat crews
in getting us and our materials onsite. For this we thank John Provo,
Dwight Willey, Keith Duran, and Diane Brooks. Yvonne Morales again
effectively coordinated logistics and travel for the annual island fox
meeting.

Thanks finally to the Park management team and the rest of the Park
staff for supporting these critical emergency actions for island fox
recovery. We especially appreciate the support of Kate Faulkner, Chief
of Natural Resources Management, Superintendent Russell Galipeau, and
Chief Ranger Jack Fitzgerald. Thanks to Cathy Schwemm, David Graber,
Peter Dratch and Bridget Fahey, who comprise the park's island fox
steering committee; their counsel continually guides our program. We
also appreciate the efforts of those beyond the Park who have recognized
the plight of island foxes, and have helped garner the resources
necessary to effect recovery. For this we thank Dave Graber, Patty
Neubacher and Jay Goldsmith.

TABLE OF CONTENTS

Executive Summary [1](#executive-summary)

Introduction [4](#introduction)

2003 Meeting of the Island Fox Conservation Working Group
[6](#meeting-of-the-island-fox-conservation-working-group)

Captive Breeding Program Development
[8](#captive-breeding-program-development)

The Need for Captive Breeding as a Recovery Action
[8](#the-need-for-captive-breeding-as-a-recovery-action)

Goals and Objectives for Captive Breeding
[8](#goals-and-objectives-for-captive-breeding)

Program Guidance [9](#program-guidance)

Standard Operating Procedures [9](#standard-operating-procedures)

Facility Design and Construction [9](#facility-design-and-construction)

Veterinary Care [9](#veterinary-care)

Caretaking and Handling [10](#caretaking-and-handling)

Breeding Strategy [10](#breeding-strategy)

Diet [10](#diet)

Overall Breeding Success [11](#overall-breeding-success)

Recovery of San Miguel Island Foxes
[13](#recovery-of-san-miguel-island-foxes)

Captive Breeding [13](#captive-breeding)

Health/Medical [14](#healthmedical)

Future Management of San Miguel Captive Island Foxes
[16](#future-management-of-san-miguel-captive-island-foxes)

Status of Wild Fox Population [16](#status-of-wild-fox-population)

Recovery of Santa Rosa Island Foxes
[18](#recovery-of-santa-rosa-island-foxes)

Captive Breeding [18](#captive-breeding-1)

Health/Medical [18](#healthmedical-1)

Future Management of Santa Rosa Captive Island Foxes
[19](#future-management-of-santa-rosa-captive-island-foxes)

Status of Wild Fox Population [19](#status-of-wild-fox-population-1)

Reintroduction of Santa Rosa Island Foxes
[20](#reintroduction-of-santa-rosa-island-foxes)

Recovery of Santa Cruz Island Foxes
[24](#recovery-of-santa-cruz-island-foxes)

Captive Breeding [24](#captive-breeding-2)

Health/Medical [25](#healthmedical-2)

Future Management of Santa Cruz Island Captive Foxes
[25](#future-management-of-santa-cruz-island-captive-foxes)

Status of Wild Fox Population [26](#status-of-wild-fox-population-2)

Reintroduction of Santa Cruz Island Foxes
[26](#reintroduction-of-santa-cruz-island-foxes)

Removal of Golden Eagles [28](#removal-of-golden-eagles)

Impact of Eagle Predation on Island Foxes
[30](#impact-of-eagle-predation-on-island-foxes)

Other Actions Required for Recovery
[33](#other-actions-required-for-recovery)

Removal of Feral Pigs from Santa Cruz Island
[33](#removal-of-feral-pigs-from-santa-cruz-island)

Reintroduction of Bald Eagles to Santa Cruz Island
[34](#reintroduction-of-bald-eagles-to-santa-cruz-island)

Establishment of Island Fox Recovery Team
[34](#establishment-of-island-fox-recovery-team)

Budget [36](#budget)

Future Costs [37](#future-costs)

Literature Cited [38](#literature-cited)

Appendix A Findings of the Island Fox Conservation Working Group
[41](#appendix-a-findings-of-the-island-fox-conservation-working-group)

Appendix B Breeding Charts and Lists of Foxes in Captivity
[59](#appendix-b-breeding-charts-and-lists-of-foxes-in-captivity)

####### LIST OF TABLES

Table 1. Average number of pups weaned per litter, 1999-2003.
[11](#__RefHeading___Toc69872226)

Table 2. Proportion of annual pairings that have produced litters,
1999-2003. [12](#__RefHeading___Toc69872227)

Table 3. Growth of captive island fox population, San Miguel Island.
[14](#__RefHeading___Toc69872228)

Table 4. Reproductive success of captive San Miguel Island foxes,
2002-2003 breeding season. [15](#__RefHeading___Toc69872229)

Table 5. Growth of captive island fox population, Santa Rosa Island.
[18](#__RefHeading___Toc69872230)

Table 6. Reproductive success of captive Santa Rosa Island foxes,
2002-2003 breeding season. [20](#__RefHeading___Toc69872231)

Table 7. Release location, date, release type and fate of foxes released
to the wild on Santa Rosa Island, winter 2003-2004.
[22](#__RefHeading___Toc69872232)

Table 8. Reproductive success of captive Santa Cruz Island foxes,
2002-2003 breeding season. [25](#__RefHeading___Toc69872233)

Table 9. Release location, date, release type and fate of foxes released
to the wild on Santa Cruz Island, December 2003.
[27](#__RefHeading___Toc69872234)

Table 10. Cause of mortality for radiocollared foxes on Santa Cruz
Island, December 2000 to April 2004. [30](#__RefHeading___Toc69872235)

Table 11. Costs and funding sources for island fox recovery actions,
fiscal year 2003 (1 October 2002 to 30 September 2003).
[36](#__RefHeading___Toc69872236)

Table 12. Estimated costs and funding sources for island fox recovery
actions on the northern Channel Islands, fiscal year 2004.
[37](#__RefHeading___Toc69872237)

Table 13. Island foxes in captive breeding facility on San Miguel
Island. [60](#__RefHeading___Toc69872238)

Table 14. Island foxes in captive breeding facility on Santa Rosa
Island. [62](#__RefHeading___Toc69872239)

Table 15. Island foxes in captive breeding facility on Santa Cruz
Island. [64](#__RefHeading___Toc69872240)

####### LIST OF FIGURES

Figure 1. Growth of captive island fox populations, 1999-2003.
[1](#__RefHeading___Toc73507707)

Figure 2. Location of island fox captive breeding facilities, San Miguel
Island. [13](#__RefHeading___Toc73507708)

Figure 3. Location of island fox captive breeding facilities, Santa Rosa
Island. [17](#__RefHeading___Toc73507709)

Figure 4. Most recent locations for island foxes released to the wild in
winter 2003-2004, Santa Rosa Island. RM-01, RF-102, RM-02 and RF-103
have been recaptured and returned to captivity.
[23](#__RefHeading___Toc73507710)

Figure 5. Location of island fox captive breeding facilities, Santa Cruz
Island. [24](#__RefHeading___Toc73507711)

Figure 6. Golden eagles remaining on the northern Channel Islands, March
2004. [29](#__RefHeading___Toc73507712)

Figure 7. Rolling annual survivorship, with 95% CI, of wild island foxes
on Santa Cruz Island, as determined by staggered entry Kaplan-Meier
analysis. [32](#__RefHeading___Toc73507713)

Figure 8. Breeding and pedigree chart for captive San Miguel Island
foxes. [60](#__RefHeading___Toc73507714)

Figure 9. Breeding and pedigree chart for captive Santa Rosa Island
foxes. 62

Figure 10. Breeding and pedigree chart for captive Santa Cruz Island
foxes. 64

![](media/image1.jpeg){width="4.040972222222222in"
height="5.164583333333334in"}

# 

# Executive Summary![](media/image2.wmf){width="3.484722222222222in" height="2.3895833333333334in"}

From 1995 to 2000, island fox (*Urocyon littoralis*) populations on San
Miguel, Santa Rosa and Santa Cruz Islands declined by as much as 95% due
to predation by golden eagles (*Aquila chrysaetos*). Faced with the
likely extinction of 3 island fox subspecies, the National Park Service
began implementing recovery actions for island foxes on the northern
Channel Islands in 1999. Such actions included removal of golden eagles
and captive breeding of island foxes. In this report we describe
progress in island fox recovery in 2003.

Summary

Of utmost importance to the recovery effort is the impact of golden
eagles on both wild foxes and foxes released from captivity. In 2003,
continued removal of golden eagles resulted in rising annual
survivorship of wild island foxes on Santa Cruz Island. However, over
half of the captive foxes released to the wild on Santa Cruz Island in
2003 were killed by golden eagles within several weeks of release. In
comparison, only 1 of 8 foxes released on Santa Rosa Island in 2003-2004
died from predation. Reintroduction of captive foxes to the wild is not
an effective recovery tool under the high predation rate observed on
Santa Cruz Island. If predation can be sufficiently mitigated, then
releases would continue on Santa Cruz and Santa Rosa Islands in fall
2004, and initial releases could be conducted on San Miguel Island.
However, if foxes cannot be released to the wild in fall 2004 because of
the threat of eagle predation, then moving a portion of the breeding
program to mainland institutions should be considered.

Captive Breeding

Generally, captive fox populations on the islands grew at adequate
rates. However, in 2003 the rising cost of keeping foxes in captivity on
the islands, both financially and biologically, became apparent. Several
problems arose in captivity that we had not previously encountered.
First, 3 pairs that had previously produced litters failed to reproduce
in 2003, probably due to leaving a pup from the previous year in their
pens. Second, several males injured their mates during breeding season,
and had to be separated from them; production from those prospective
pairings is thus lost for the 2003-2004 breeding season. Third, some
released foxes dispersed from their release sites to the captive pen
areas, and their interactions with captive foxes caused injury to both
wild and captive animals.

Captive island fox populations grew to levels in 2003 that were at or
close to the targeted captive breeding population size of 40 foxes (20
pairs) (Fig. 1), and reproductive success in captivity was similar to
that observed in the wild. Since 1999, 20% of young adult females have
produced a litter in captivity, as have 60% of older females. Average
number of pups weaned per litter was 2.3.

San Miguel Island Foxes

The captive population of San Miguel island foxes (*U. l. littoralis*)
grew from 28 to 38 individuals with the addition of 10 pups in spring
2003. The San Miguel population remains skewed toward males (23 males:15
females). Seven of 14 potential founders (wild-born foxes) had
successfully bred by 2003. The last remaining wild fox was trapped and
brought into captivity in November 2003, although she died a month
later. Production in spring 2004 from the 15 pairs should put the
captive population above 20 pairs, and releases to the wild will
commence in fall 2004 if eagle predation has been sufficiently
mitigated.

Santa Rosa Island Foxes

The captive population of Santa Rosa Island foxes (*U. l. santarosae*)
grew from 45 to 56 foxes in captivity, with the birth of 11 pups in
spring 2003. In winter 2003/2004 initial releases to the wild of captive
Santa Rosa foxes commenced. Twelve foxes were released to the wild from
December 2003 to February 2004. Four of the released animals were
recaptured and brought back into captivity because their use area
included the captive pen facilities, and interactions between captive
and released foxes had resulted in injuries to 2 captive and 2 wild
foxes. To prevent this, perimeter fences will be constructed around
captive breeding facilities in summer 2004. Of the 8 released foxes
remaining in the wild, 1 died from eagle predation in February 2002. The
Santa Rosa Island fox captive population is skewed toward females (19
males:28 females), and 11 of 14 potential founders had bred by 2003. Two
males are currently not paired for breeding because they have a history
of causing injuries to potential mates.

Santa Cruz Island Foxes

Unlike San Miguel and Santa Rosa islands, Santa Cruz Island has a
remnant wild population numbering around 100. Because of this, the
captive breeding program on Santa Cruz is not as large as on the other
two islands. In 2003 the captive Santa Cruz Island fox population (*U.
l. santacruzae*) grew from 20 to 30 foxes with the production of 10 pups
in spring 2003. Nine foxes were released to the wild in December 2003.
Five of the 9 foxes died from eagle predation within 3 weeks of release,
and so the remaining 4 foxes were brought back into captivity in January
2004. The Nature Conservancy is building a second captive breeding
facility on Santa Cruz Island in order to adequately house the current
number of captive foxes, as well as pups likely to be produced in spring
2004.

Removal of Golden Eagles

Using live-trapping methods, staff from the Santa Cruz Predatory Bird
Research Group removed 7 golden eagles from Santa Cruz Island, and 2
from Santa Rosa Island, bringing to 31 the total number of eagles
removed from the islands since 1999. Eagles captured in 2003 included 2
adult males, 1 subadult female, 2 subadult males, 1 near adult male, 1
juvenile female, and 2 fledglings captured by hand in nests. One of the
adult males was from a territorial pair (Trap Canyon on Santa Rosa
Island). At the end of 2003 there were as many as 14 golden eagles left
on Santa Cruz and Santa Rosa Islands, including 4 pairs likely to breed
in spring 2004. Intensive live-trapping will occur in spring 2004 to
remove as many of the remaining eagles as possible.

Impact of Remaining Eagles on Foxes

Radiotelemetry monitoring of the wild Santa Cruz Island fox population
indicated that annual survivorship had risen to above 80% by the end of
2003, which is the level required for a stable or increasing population.
There appears to be a substantial difference between survivorship of
wild foxes on Santa Cruz Island and survivorship of captive-raised foxes
released to the wild on that island.

Health of Captive Island Foxes

One fox died in captivity on San Miguel in 2003, and 2 on Santa Rosa in
early 2004. Two of the 3 foxes died from wounds inflicted by penmates,
in one case a male, and in the other several females. The third
mortality was due to chronic kidney failure.

Several captive foxes suffered from prolapsed rectums, which could
possibly be caused by parasites. Captive foxes on San Miguel harbor 3
parasites with potential to impact fox health: *Angiocaulus*,
*Spirocerca* and *Uncinaria*. Foxes on Santa Rosa have not tested
positive for *Angiocaulus*. To date few foxes have been treated for
internal parasites, due to the unknown risks associated with such
treatment. Some foxes on Santa Rosa and Santa Cruz had significant flea
infestations, and were treated during annual veterinary exams. All
captive foxes are vaccinated annually against canine distemper virus
(CDV). Three necropsied foxes had evidence of surviving a previous
raptor attack.

Other Management Actions Required

The Nature Conservancy and the NPS will begin removal of feral pigs
(*Sus scrofa*) from Santa Cruz Island in 2004, a project that is
estimated to take 2-4 years to complete. The NPS is also cooperating
with other agencies in a feasibility study to determine if bald eagles
(*Haliaeetus leucocephalus*) can be restored to the northern Channel
Islands. In the summer of 2002, 12 eaglets were reintroduced to Santa
Cruz Island, and 11 in 2003. Of those eagles, 15 remain on the northern
Channel Islands. Annual supplementation with up to 12 eagles will
continue until 2007.

Annual Working Group Meeting

The Island Fox Conservation Working Group, a loose affiliation of
entities concerned with conservation of island foxes, met again in 2003
to consider current conservation challenges faced by the species. The
primary issue identified by the group was the threat posed by the
remaining golden eagles. The group recommended that lethal removal be
considered as an option for eagle removal.

# Introduction

The island fox, a diminutive relative of the gray fox (*U.
cinereoargenteus*), is endemic to the California Channel Islands. The
fox exists as 6 different subspecies on each of the 6 islands, a
distinction upheld by morphological and genetic work (Wayne et al. 1991,
Collins 1993). The subspecies on the 3 northern Channel Islands are in
genuine danger of extinction from unnatural levels of golden eagle
predation and from extremely low population levels.

In December 2001, the U.S. Fish and Wildlife Service proposed for
listing as endangered 4 subspecies of the island fox, including the 3
subspecies in the Park (San Miguel Island fox \[*U.l. littoralis*\];
Santa Rosa Island fox \[ *U.l. santarosae*\], and Santa Cruz Island fox
\[*U.l. santacruzae*\]) as well as the subspecies on Santa Catalina
Island (*U.l. catalinae*). The final rule listing those subspecies as
endangered was published in the Federal Register on March 5, 2004 (USFWS
2004).

Island fox populations were annually monitored on San Miguel Island from
1993 to 1999, and on Santa Cruz Island from 1993 to present. The island
fox population on San Miguel declined beginning in 1994 with the adult
population falling from 450 in 1994 to 15 in 1999 (Coonan et al. in
review). The Santa Cruz population declined from approximately 2,000
adults in 1994 to perhaps less than 135 in 2000 (Roemer 1999), and the
current population is probably less than 100 adults (D. Garcelon,
Institute for Wildlife Studies, unpubl. data). Survey data from Santa
Rosa Island (G. Roemer, Institute for Wildlife Studies, unpublished
data) indicate that island foxes experienced a similar catastrophic
decline on that island as well. Foxes on Santa Rosa may have numbered
more than 1,500 in 1994 (Roemer et al. 1994) but declined to 14 animals
by 2000 (Coonan and Rutz 2001. Prior to implementation of island fox
recovery efforts, Roemer (1999) estimated time to extinction at 5 years
for island foxes on San Miguel and 12 years for island foxes on Santa
Cruz.

Predation by golden eagles (*Aquila chrysaetos*) is the primary
mortality factor now acting upon island foxes on the northern Channel
Islands, and is likely responsible for the massive decline of the 3
northern subspecies from 1994 to 2000 (Roemer et al. 2001a). Evidence
from several studies supports this. Golden eagle predation was
identified as cause of death for 19 of 21 island fox carcasses found on
Santa Cruz Island from 1993 to 1995 (Roemer et al. 2001a). On San Miguel
Island in 1998-1999, 4 of 8 radiocollared island foxes were killed by
golden eagles in a 4-month period, and another 2 died of unknown causes
(Coonan et al. in review). In 2001-2002, 15 of 18 mortalities of
radiocollared foxes on Santa Cruz Island were due to golden eagle
predation (D. Garcelon, Institute for Wildlife Studies, unpubl. data).

The observed level of golden eagle predation is unnatural. Until
recently, golden eagles have never bred on the Channel Islands and their
recent appearance is due to a prey base, feral pigs (*Sus scrofa*), that
was not present prehistorically. The absence of bald eagles (*Haliaeetus
leucocephalus*), which bred historically on the islands and whose
presence may have kept golden eagles away, is another factor
contributing to golden eagle predation. Moreover, on much of the
northern Channel Islands, historic sheep grazing changed the predominant
vegetation from shrub to non-native grasslands, which offer much less
cover from aerial predators.

Upon receiving recommendations from a convened panel of experts, the
Park began taking emergency recovery actions in 1999. In summer 1999,
the Park constructed pens on San Miguel and began capture of wild island
foxes. By January 2000, 14 island foxes had been captured and placed in
the pens. Four of those were males, and so were paired with 4 females
for breeding. The captive population on San Miguel increased from 14 to
38 animals after 4 years of breeding. A successful 2004 breeding season
(\>10 pups) could put the captive San Miguel island foxes in position
for initial releases to the wild in fall 2004.

A captive breeding program was initiated for Santa Rosa Island in 2000.
The initial captive population on Santa Rosa was 14 animals, which
proved to be the island's remaining fox population. Some females were
pregnant when captured, and 3 litters were born in captivity in 2000.
With an increase to 56 foxes in 2003, the captive population on Santa
Rosa exceeded the target captive population size of 40 foxes, and
initial releases began in winter 2003/2004.

The status of eagles and foxes on Santa Cruz Island was assessed at the
2001 Recovery Team Meeting, and indications were that captive breeding
was warranted for that island fox population. In February 2002, a 10-pen
captive breeding facility was built on Santa Cruz Island by the National
Park Service and The Nature Conservancy. This facility was stocked with
12 adult island foxes caught in pairs or as individuals from separate
areas of the island. The captive population increased to 30 foxes in
2003, and small releases were conducted in 2002 and 2003.

The Park established a cooperative agreement with the Santa Cruz
Predatory Bird Research Group (SCPBRG) in 1999 for the purpose of
relocating golden eagles from the northern Channel Islands. Personnel
from the SCPBRG began eagle survey and removal on Santa Cruz Island, the
island with the most recent sightings, in late summer 1999. Golden
eagles are now known to breed on both Santa Cruz and Santa Rosa Islands.
To date 32 golden eagles have been removed from Santa Cruz Island, the
majority by bownet trapping. Captured birds were released in
northeastern California, and satellite telemetry indicates none have
attempted to return to the islands. Approximately 11 eagles remain on
Santa Cruz and 3 on Santa Rosa.

In August 2003, the Park completed a recovery strategy for island foxes
on the northern Channel Islands (Coonan 2003). The recovery strategy is
in the format of a U.S. Fish and Wildlife Service recovery plan,
identifying threats to the species, delineating goals, objectives and
recovery criteria, and presenting a schedule and cost estimates for
recovery actions. Appropriate recovery goals for each of the 3 island
fox subspecies in the northern Channel Islands were determined via
demographic modeling. Population viability analysis was used to identify
target population levels which would minimize the chance of extinction.
Modeling was then used to set an augmentation (captive breeding and
release) schedule that would achieve those targeted goals in a
reasonable timeframe.

The island fox recovery strategy calls for a continuation of the
emergency actions of island fox captive breeding and golden eagle
removal, as well as the separately funded actions of feral pig removal
from Santa Cruz Island and reintroduction of bald eagles to the northern
Channel Islands. Full recovery of the San Miguel subspecies may take as
long as a decade, although recovery on Santa Rosa and Santa Cruz may
occur sooner. The plan was developed with input from U.S. Fish and
Wildlife Service, and could be adopted as part of a FWS recovery plan
for the species, now that the three park subspecies are listed.

## 2003 Meeting of the Island Fox Conservation Working Group

Since 1999, the NPS has convened a group of experts annually to help
evaluate the status of island foxes on park lands, and to make findings
regarding appropriate recovery actions. The Island Fox Conservation
Working Group, as it is called, is a loose affiliation of public agency
representatives, landowners, conservancies, zoological institutions,
non-profits and academics concerned about conservation efforts for the
island fox.

The working group serves as a forum for information exchange and
evaluation of recovery efforts. The working group communicates primarily
through an annual meeting, but also via email and telephone conference
calls. The group further divides into subject matter groups to tackle
most issues. The individual working groups for this year's meeting were
captive breeding, veterinary care, wild population management, and
reintroduction of island foxes. The group annually reports the status of
island foxes on all islands and lists findings in regard to threats to
the species and appropriate mitigation actions (see Appendix A).

The primary issue identified by the group in 2003 was the inability of
live-capture efforts to remove all golden eagles from the northern
Channel Islands, and the continued threat to island foxes posed by the
remaining eagles. Consensus of the group was that eagle predation had
not been sufficiently mitigated by live-capture methods, and that lethal
control of eagles must be considered if island foxes were to be
recovered. The group also noted the recent discovery of breeding golden
eagles on Santa Rosa Island, and the presence of a non-native prey base
(mule deer and elk) there. One discussion group recommended that deer
carcasses and gut piles from the deer hunt on that island be made
unavailable to eagles.

The Working Group was divided on whether it was advisable to release
foxes to the wild under these conditions, but recognized that if foxes
could not be released, the park should consider the option of moving a
portion of captive breeding to mainland institutions. This would require
adequate quarantine and treatment procedures to insure no transmittal of
pathogens (disease and parasites) from the islands to the mainland, or
from the mainland to the islands.

Due to the formidable threat posed by canine diseases and parasites, the
veterinary group recommended that all dogs used on park islands undergo
strict vaccination and quarantine prior to arriving on the island.

![](media/image3.jpeg){width="6.403472222222222in"
height="4.797916666666667in"}

# Captive Breeding Program Development

## The Need for Captive Breeding as a Recovery Action

The Park's island fox recovery plan (Coonan 2003) identifies captive
breeding as a critical recovery element necessary to recover island fox
populations to viable levels on the northern Channel Islands. Current
island fox populations on San Miguel, Santa Rosa, and Santa Cruz Islands
number 38, 54, and \<100 foxes, respectively. The probability of
extinction is high for these critically low populations (Roemer et al.
2001b) and the populations require augmentation to reach viable levels.
Demographic modeling suggests that an appropriate augmentation schedule
can return island foxes to viable population levels within a reasonable
timeframe (a decade). The original island fox recovery team and the
current Island Fox Conservation Working Group recommend captive breeding
as a recovery action. Once golden eagles are removed from the northern
Channel Islands, captive breeding will be the most important recovery
action implemented for island foxes, and will require commitments of
resources and personnel far exceeding any other recovery action. In this
context we report on the status of the program after 4 years of
breeding.

## Goals and Objectives for Captive Breeding 

The following goals and objectives for the island fox captive breeding
program at Channel Islands National Park were developed upon
consultation with the captive breeding sub-group of the Island Fox
Conservation Working Group.

OVERALL GOAL

To develop a captive breeding program for island foxes on San Miguel
Island (*U. l. littoralis*), Santa Rosa Island (*U. l. santarosae*) and
Santa Cruz Island (*U. l. santacruzae*) in order to increase their wild
populations to viable levels.

OVERALL OBJECTIVE

To design and implement captive breeding programs for the primary
purpose of generating animals suitable for reintroduction into
appropriate habitat, once the threats to the populations in those
habitats have been minimized or eliminated.

SPECIFIC OBJECTIVES

1.  Define scope and duration of program; set facility size and
    configuration.

2.  Construct and populate breeding facilities for the San Miguel, Santa
    Rosa and Santa Cruz Island fox populations.

3.  Pair animals for breeding; monitor breeding behavior and results.

4.  Develop appropriate release strategies.

5.  Release foxes annually back into the wild; monitor wild foxes.

## Program Guidance

Guidance for the captive breeding program has been provided generally by
the captive breeding and veterinary sub-groups of the Island Fox
Conservation Working Group, and their findings and recommendations have
been incorporated into the Park's captive breeding program (Coonan and
Rutz 2001, 2002, 2003). For guidance in design of captive enclosures and
development of husbandry protocols, we consulted the American Zoological
Associations' management recommendations for small canids in captivity,
as well as the American Society of Mammalogists' guidelines for the
capture, handling and care of mammals (American Society of Mammalogists
1987). Further guidance is provided annually by the Island Fox
Conservation Working Group.

## Standard Operating Procedures

The following standard operating procedures have been developed for the
captive breeding program:

### Facility Design and Construction

-   In order to minimize the chance of disease, parasites or other
    catastrophe causing extirpation of captive populations, San Miguel
    and Santa Rosa Islands each have two separate breeding facilities.

-   Staff level must be adequate for caretaking 40-50 animals at two
    sites.

-   Sufficient distance is maintained between pens, while within the
    pens hiding places are provided; thus animals have visual contact
    with others when they choose.

-   Annual pen construction is completed by October to allow pairs
    sufficient time to bond prior to breeding.

-   There should is a minimum of two isolation areas at each facility.

-   The threat of wildfire at captive breeding facilities is addressed
    by the Park's fire management program, and Vari-Kennels are
    available for immediate evacuation of foxes.

### Veterinary Care

-   If foxes are brought to the mainland for veterinary care, they
    cannot be returned to the islands, because of possible
    disease/parasite transmission.

-   Captive foxes are given regular veterinary examinations, using a
    standardized veterinary protocol.

-   Each captive breeding population has access to a
    veterinary/quarantine facility where animals may be treated.

-   Protocols are implemented to minimize the risk of people or
    equipment transferring pathogens among islands, and to minimize
    parasite loads in the captive populations.

### Caretaking and Handling

-   Human contact with captive foxes is minimized to avoid acclimating
    them to humans, and to ensure they are as wild as possible upon
    release.

-   Handling and disturbance of captive island foxes is avoided during
    the full extent of the breeding season (January through June).

### Breeding Strategy

-   Mated pairs are kept together as long as they reproduce
    successfully; non-reproductive pairs are kept together for at least
    two breeding seasons.

-   Pairings of siblings or parent/offspring are avoided using
    genotyping of individual animals, and estimation of relatedness.

-   Video monitoring is used to the extent practicable to document
    breeding behavior or lack thereof, and to record birth dates, pup
    fate, and neonatal care.

-   Captive-born foxes are preferentially paired with wild-born
    individuals, provided existing pairs are not broken up, to minimize
    loss of wild behavioral traits.

-   Birth, death and breeding records are maintained in a studbook.

-   Excess females may be housed together if compatible to allow for
    social interaction or to possibly test reproductive potential of one
    male with two females. However, no more than two females should be
    housed together in one pen.

### Diet

-   The fox diet comprises a high-quality dry dog (24% crude protein,
    14% crude fat) (Innova® Dog Food™, Natura Pet Products, Santa Clara,
    CA) supplemented with hard-boiled eggs, and a variety of fruits and
    vegetables. This is supplemented several times per week by live deer
    mice or dead coturnix quail.

-   Captive foxes are not given moist meat-based food, such as canned
    cat or dog food, or fruits high in citric acid, since they may cause
    gingivitis and tooth loss.

-   The amount of food given daily is on average 3-4% dry weight of the
    foxes' body weight (i.e., a 2.3 kg adult receives 90 g of food
    daily).

-   During breeding season, females suspected to be pregnant or with
    litters are fed dog kibble with higher crude protein (26%) and more
    essential fatty acids (Innova® Puppy Food™, Natura Pet Products,
    Santa Clara, CA). Family groups are fed this diet until the pups
    reach adult body size (October).

## Overall Breeding Success

In 2003, the San Miguel captive population increased from 28 to 38
individuals, with 10 pups born to 5 litters. On Santa Rosa the captive
population increased from 45 to 56 individuals with 11 pups born to 4
litters. On Santa Cruz the captive population increased to 30
individuals with the addition of 10 pups born to 5 litters.

Fourteen of 38 paired females produced litters in 2003 (37%) compared to
9 of 21 in 2002 (43%) and 7 of 13 in 2001 (54%). The percentage of
successfully breeding females declined because only 1 of 17 pairings
involving captive-born females has produced a litter, and only 5 out of
10 female founders on San Miguel have bred. Thus the number of founders
remains low on San Miguel (7; see Appendix C). This is, in part, a
consequence of a lack of males. Only 4 of 14 animals brought into
captivity in 1999 were males. On Santa Rosa, 11 of 14 potential founders
have bred.

Overall, reproductive output is similar to that observed in the wild.
The average number of pups weaned in captive litters (2.3, n = 35
litters) is similar to the average number of pups weaned in the wild on
San Miguel from 1993 to 1998 (2.0, n = 34) (Coonan et al. in review).
Among the captive populations, the number of pups weaned per litter was
slightly higher on Santa Cruz Island (Table 1), but this is heavily
influenced by 1 litter of 5 pups weaned in 2002.

The proportion of females that produced litters was also similar to that
observed in the wild. In captivity, 31 of 78 annual pairings (39.7%)
have produced litters (Table 2), compared to 42.8% in the wild (54/126
pairings; Coonan et al. in review). The proportion of females breeding
was higher on Santa Rosa and Santa Cruz than on San Miguel (Table 2).

Female age was a factor in reproduction, as in the wild. The proportion
of Age Class I females (1-2 years old) breeding in captivity was 22.7%,
similar to the 19% observed in the wild (Coonan et al. in review). The
proportion of older females that bred in captivity (47.3%) was less than
that observed in the wild on San Miguel (60.0%; Coonan et al. in
review).

Mate history affected likelihood of breeding. Most captive fox pairs
were not successful in their first year of mating. Only 32.6% of 43
first-year matings were successful, whereas 66.7% of 34 second and
third-year matings were successful.

[]{#__RefHeading___Toc69872226 .anchor}Table 1. Average number of pups
weaned per litter, 1999-2003.

  ------------------------- ------------------------- -------------------
  **Island**                **Avg. No. of Pups        **n**
                            Weaned**                  

  San Miguel                2.3                       11

  Santa Rosa                2.3                       18

  Santa Cruz                2.5                       6
  ------------------------- ------------------------- -------------------

[]{#__RefHeading___Toc69872227 .anchor}Table 2. Proportion of annual
pairings that have produced litters, 1999-2003.

  ---------------- --------------- ------------ ------------ --------------
  **Island**       **Litter**      **No         **Total**    **% Success**
                                   Litter**                  

  San Miguel       11              20           31           35.5

  Santa Rosa       15              21           36           41.7

  Santa Cruz       5               5            10           50.0

  Total            31              47           78           39.7
  ---------------- --------------- ------------ ------------ --------------

Another factor affecting the growth of the captive populations is the
uneven sex ratios in the captive-born litters. The sex ratio is biased
toward males on San Miguel (23 males:15 females), where males comprise
19 of 25 pups (76%) born in captivity. On Santa Rosa, the sex ratio is
biased toward females (19 males:28 females), and of the 42 pups born, 26
have been female. There were 11 unmated animals on Santa Rosa and San
Miguel in 2001, 8 unmated animals in 2002, and 17 in 2003.

In summary, reproductive success for captive foxes was similar to that
of wild foxes from San Miguel from 1993-1998. Age Class I females rarely
bred, and the average number of pups weaned was similar for captive and
wild foxes. First-year matings were successful only a third of the time.
There has been a general failure of captive-born females to breed,
though many of these matings were of first-year animals.

# 

# 

# Recovery of San Miguel Island Foxes

## Captive Breeding![](media/image4.wmf){width="6.1819444444444445in" height="4.776388888888889in"}

During 2003, the San Miguel captive population grew from 28 to 38 foxes
(Tables 3 and 4). The 1 fox left in the wild was captured in September
2003, but died in captivity on December 31, 2003. Ten pups, 7 males and
3 females, were born to 5 litters in April 2003 (Table 5). Two potential
founder females (71071 and F6558) bred for the first time in 2003,
bringing the number of founders to 7. Seven pairings, including 4 other
potential founder females, did not produce litters. Of the 7, 5 were
first-year pairs which are generally less likely to breed. Three pairs
were split, and the individuals were assigned new mates for the
2003-2004 breeding season.

In November, pairings were made for the 2003-2004 breeding season. There
are 15 pairs on San Miguel for the breeding season, with 8 unmated
males. Changes for the 2004 season include new pairings for 2 potential
founder females, B0B25 and 7534A, who had failed previously with 1 and 2
males, respectively.

Genetic analysis conducted on the captive fox populations (Gray and
Roemer 2001) had allowed previous determination of relatedness among
foxes and was used to select new pairings. However, there is substantial
overlap of relatedness ("r") values for related and unrelated foxes on
San Miguel, due to the lack of genetic variation in the population, and
the level of genetic variation in the population has declined since 1988
(Gray and Roemer 2001).

[]{#__RefHeading___Toc69872228 .anchor}Table 3. Growth of captive island
fox population, San Miguel Island.

  ------------ ------------ ------- ------- ----------- ---------- ------- ----------- ---------- -------------
               **Adults**                               **Pups**                                  **Total**

  **Year**                  **F**   **M**   **Total**   **F**      **M**   **Total**   **Died**   **Captive**

  2000                      10      4       14\*        1          1       2           0          16

  2001                      11      5       16          0          5       5           1          20

  2002                      10      10      20          2          6       8           0          28

  2003                      15      23      38          3          7       10          1          38

  \*Founding                                                                                      
  population                                                                                      
  ------------ ------------ ------- ------- ----------- ---------- ------- ----------- ---------- -------------

### Health/Medical

One fox died in captivity on San Miguel in 2003. The last wild fox on
San Miguel, female 85619, was captured and brought into captivity in
September 2003, but died on December 31 2003, from wounds apparently
inflicted by her penmate (see Status of Wild Fox Population, below).

Since 1999 there have been 2 deaths in captivity on San Miguel, the
previous occurring in December 2001, when an older, unmated female died
of old-age related conditions.

Veterinary examinations on San Miguel foxes were conducted by project
veterinarian Mark Willett, DVM, in July 2003. Routine general physical
examinations were performed in a nose to tail fashion, and included
otoscopic examination. Blood samples were obtained from all animals for
complete hematology and blood chemistry analysis.

Foxes examined in 2003 were generally in good health. There is a
conspicuous absence of ectoparasites in the San Miguel foxes, compared
to Santa Rosa foxes, and there is very little problem with crusty eyes.

Captive foxes on San Miguel Island have 3 internal parasites which have
the potential to pose significant health problems: *Angiocaulus*,
*Spirocerca*, and *Uncinaria*. Of the 3, *Uncinaria*, or hookworm, poses
the least threat to fox health, as it is relatively innocuous compared
to other hookworms, such as *Ancylostoma caninum* (Georgi and Georgi
1991). *Angiocaulus* is not found in foxes from other islands (L.
Munson, UC Davis, unpubl. data). Whereas the pathogenicity of
*Angiocaulus* is largely unknown, necropsy of a San Miguel island fox
indicated that *Angiocaulus* had caused extensive pulmonary granulomas
and was present in heart blood. If such foxes were treated with an
anthelmintic which crossed into the bloodstream and killed the
*Angiocaulus*, a fatal outcome might occur (Linda Munson, UC Davis,
pers. comm.). Moreover, *Spirocerca* are present in the wall of the
colon and, if killed by an anthelmintic, may cause an inflammatory
reaction that could result in an intestinal rupture.

To date foxes have not been treated for *Angiocaulus* or *Spirocerca*,
because there are no clinical signs warranting such treatment, and the
risks of treating foxes for such novel parasites are unknown. A risk
analysis currently being conducted by the U.S.G.S. Biological Resource
Division's Wildlife Health Center (R. Sohn, U.S.G.S. Biological
Resources Division, unpubl. data) will present recommendations for
treatment of individual animals for internal parasites.

One San Miguel fox developed a prolapsed rectum in September 2003. The
prolapse repaired itself. This was the second instance of a prolapsed
rectum on San Miguel; the first occurred in female 92C32 in 1999. There
have been several other prolapsed rectums on Santa Rosa Island, and
necropsy of 1 Santa Cruz Island fox revealed cause of death to be
septicemia brought about by necrosis of a prolapsed rectum. The prolapse
may have been caused by a *Spirocerca* granuloma in the lower intestine
(L. Munson, University of California, Davis, unpubl. data).

[]{#__RefHeading___Toc69872229 .anchor}Table 4. Reproductive success of
captive San Miguel Island foxes, 2002-2003 breeding season.

  --------- -------- --------- ------------ ------------ ------------ ------------ ------------
  **Pen**   **ID**   **Sex**   **Age^1^**   **Paired**   **Result**   **Litter     **Birth
                                                                      Size**       Date**

  M01       85764    F         1            11/2/2002    No Litter                 

            87F53    M         1                                                   

  M03       92C32    F         5            7/16/1999    Litter       3            ≈4/10/2003

            7574A    M         5                                                   

  M07       90D1A    F         5            9/4/1999     Litter       1            ≈4/10/2003

            44829    M         5                                                   

  M09       7534A    F         10           10/17/2001   No Litter                 

            83C24    M         2                                                   

  M11       E2677    F         5            10/17/2000   Litter       2            ≈4/10/2003

            47B06    M         3                                                   

  M12       B0B25    F         4            10/17/2001   No Litter                 

            70C1D    M         2                                                   

  M13       F6558    F         4            10/17/2002   Litter       2            ≈4/10/2003

            11F73    M         2                                                   

  M14       60921    F         5            10/27/2002   No Litter                 

            57150    M         5                                                   

  M15       B7E0A    F         1            11/4/2002    No Litter                 

            B0E36    M         1                                                   

  M17       11929    F         3            10/17/2001   No Litter                 

            C7303    M         2                                                   

  M18       71071    F         4            10/17/2001   Litter       2            ≈4/10/2003

            C4A16    M         2                                                   

  M19       92804    F         11           10/27/2002   No Litter                 

            85D02    M         4                                                   

  ^1^In                                                                            
  years, as                                                                        
  of fall                                                                          
  2002                                                                             
  --------- -------- --------- ------------ ------------ ------------ ------------ ------------

It is possible that foxes with *Spirocerca* and a history of prolapse
will be treated with an anthelminthic to prevent such fatal results.

All adult foxes in captivity on San Miguel received both the initial and
booster doses of CDV vaccine (Merial Ltd., Athens, GA) during vet
examinations in summer 2003. The vaccine is a canary pox vectored
recombinant canine distemper virus used successfully on Santa Catalina
island foxes (Kohlmann et al. 2003).

### Future Management of San Miguel Captive Island Foxes

Of the 38 foxes in captivity, 15 are females, and thus there are 15
mated pairs for the 2003-2004 breeding season, with 8 unmated males. In
2002-2003, 12 pairs produced 10 pups in 5 litters. The 15 pairs for the
upcoming breeding season are therefore likely to produce 12 pups, of
which perhaps 4 will be females (assuming the consistent male bias in
pups continues). The captive population is likely to number 50 foxes by
summer 2004, with a total of 19 pairs for the 2004-2005 breeding season,
and 12 unmated males.

Capacity of the captive facility is 40 animals (20 breeding pens). If
eagle predation is sufficiently mitigated by fall 2004, initial releases
of San Miguel foxes to the wild may occur. But if eagle predation is not
sufficiently mitigated and the decision is made to keep foxes in
captivity, then either 10 additional pens must be built on the island,
or a portion of the captive breeding program must be moved to mainland
institutions. The latter would require development of adequate
quarantine, vaccination and treatment procedures for insuring that
pathogens are not transferred between the mainland and the island, or
the island and the mainland. A sub-group of the Island Fox Conservation
Working Group is currently developing a risk assessment to determine if
such procedures can be developed.

## Status of Wild Fox Population

A National Park Service crew from Santa Monica Mountains National
Recreational Area captured the last wild fox, 85619, on San Miguel on
September 26, 2003, using padded leghold traps. She was placed in pen M2
by herself. In November, biopsies performed on samples from masses on
her hip and anus proved negative for cancer.

On November 24, 2003, male B0E36 was placed in her pen for breeding
purposes. Genotyping of blood samples from 85619 in relation to the
other captive foxes indicated that B0E36 had the lowest relatedness
value (r = -0.79405) of the unmated males in the population (M. Gray,
University of California, Los Angeles, unpubl. data). Keepers noticed no
agonistic/aggressive interaction between the two over the next month,
although they were never observed together.

On December 30, 2003, a volunteer caretaker on San Miguel noticed that
85619 appeared unstable. The next day, she was found dead in her pen.
Necropsy results from Dr. Linda Munson at University of California,
Davis, suggest that 85619 likely died from trauma associated with
injuries inflicted by her mate. The fox had a fractured hind leg, with
puncture wounds and extensive hemorrhages. She also had hemorrhages on
the sternum, deep near the kidneys, and around the brain, implying she
was shaken. The aged fox also had thyroid tumors, chronic kidney and
heart disease and colonic spirocercosis with an intestinal perforation.
It is possible that general debility from these other conditions incited
the cagemate aggression. Dr. Munson also found healed lesions on either
side of her ribcage, which suggests that the fox survived a previous
raptor attack. Two other necropsied foxes, one from Santa Cruz and one
from Santa Rosa Island, have shown similar lesions suggesting a failed
raptor attack. This fox had no evidence of *Angiocaulus* or *Uncinaria*.

With the capture and subsequent death of 85619, there are currently no
foxes in the wild on San Miguel Island. However, if pup production in
spring 2004 is sufficient, and if eagle predation has been sufficiently
mitigated, then initial releases to the wild may occur in fall 2004.

#  ![](media/image5.wmf){width="5.785416666666666in" height="4.470833333333333in"}

# Recovery of Santa Rosa Island Foxes

## Captive Breeding

During 2003, the Santa Rosa captive population grew from 45 to 56 foxes
with the birth of 11 pups (5 males, 6 females) to 4 litters in captivity
(Tables 5 and 6). Four of 16 pairings (25%) produced a litter in 2003
(Table 8). Three of the unsuccessful pairs (in pens R05, R07 and R09)
had previously produced litters, but female pups from the previous year
had been left in the respective pens. This may have prevented breeding
in those pairs in 2003. Five unsuccessful pairs contained juvenile
females, or were pairs with no previous history together. Eleven of 14
potential founders have bred thus far on Santa Rosa Island. In fall
2003, 4 pairs were split because they had not produced pups in 2-3
breeding seasons.

In late 2003 and early 2004, 12 Santa Rosa Island foxes were released to
the wild (see below). Four of the released foxes were returned to
captivity. Two captive foxes died in early 2004, thus leaving 46 foxes
in captivity on Santa Rosa Island. For the 2003-2004 breeding season
there are 17 pairs in captivity, including 2 pairs comprising animals
recaptured after release to the wild. There are also 2 males in
captivity that are unpaired, and are housed individually, because of
their history of injuring females with whom they have been paired. There
are 10 unmated females in the Santa Rosa Island captive breeding
facility.

[]{#__RefHeading___Toc69872230 .anchor}Table 5. Growth of captive island
fox population, Santa Rosa Island.

<table>
<colgroup>
<col style="width: 13%" />
<col style="width: 0%" />
<col style="width: 7%" />
<col style="width: 8%" />
<col style="width: 10%" />
<col style="width: 8%" />
<col style="width: 11%" />
<col style="width: 12%" />
<col style="width: 10%" />
<col style="width: 17%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="2"></td>
<td colspan="3">Adults</td>
<td colspan="3">Pups</td>
<td></td>
<td>Total</td>
</tr>
<tr class="even">
<td>Year</td>
<td colspan="2">F</td>
<td>M</td>
<td>Total</td>
<td>F</td>
<td>M</td>
<td>Total</td>
<td>Died</td>
<td>Captive</td>
</tr>
<tr class="odd">
<td>2000</td>
<td colspan="2">8</td>
<td>4</td>
<td>12<sup>1</sup></td>
<td>5<sup>2</sup></td>
<td>5<sup>2</sup></td>
<td>10</td>
<td>0</td>
<td>22</td>
</tr>
<tr class="even">
<td>2001</td>
<td colspan="2">14</td>
<td>9</td>
<td>23</td>
<td>7</td>
<td>3</td>
<td>10</td>
<td>1</td>
<td>32</td>
</tr>
<tr class="odd">
<td>2002</td>
<td colspan="2">20</td>
<td>12</td>
<td>32</td>
<td>9</td>
<td>4</td>
<td>13</td>
<td>0</td>
<td>45</td>
</tr>
<tr class="even">
<td>2003</td>
<td colspan="2">29</td>
<td>16</td>
<td>45</td>
<td>6</td>
<td>5</td>
<td>11</td>
<td>0</td>
<td>56</td>
</tr>
<tr class="odd">
<td colspan="10"><p><sup>1</sup>Founding population</p>
<p><sup>2</sup>Includes 8 pups born in captivity, and 2 pups (1 male, 1
female) born in the wild</p></td>
</tr>
</tbody>
</table>

### Health/Medical

Captive Santa Rosa Island foxes received veterinary examinations from
project veterinarian Mark Willet, DVM, in August and September of 2003.
Routine general physical examinations were performed in a nose to tail
fashion, and included otoscopic examinations. Blood samples were
obtained from all animals for complete hematology and blood chemistry
analysis.

No foxes died in captivity on Santa Rosa Island in 2003, but 2 died in
early 2004. First, female B715F, unmated and born in 2002, died on
February 3, 2004, of injuries apparently inflicted by at least 1 of her
3 penmates, all of which were unmated females. Second, male D3D76 died
of chronic kidney failure on March 5, 2004. D3D76 was a wild-born
founder who had sired 8 pups in captivity and had the most descendants
(19) of any founder. The chronic kidney failure was confirmed by the
elevated concentrations of compounds normally filtered by kidney
byproducts (blood urea nitrogen and creatinine) in annual blood samples.
The deaths of the 2 foxes in early 2004 bring the total number of
captive deaths on Santa Rosa to 3. In March 2001, founder female A7015
died of cancer.

Foxes examined were in generally good or excellent condition, with a few
exceptions. There have been 3 cases of rectal prolapse in a total of 2
foxes since 2000. One fox, male F3D2F, prolapsed during veterinary
examination in August 2002, at which time the rectum was repaired with a
purse-string suture. F3D2F suffered another prolapse in March 2004,
again requiring a suture. There is a mass on the side of his rectum
which may be causing the prolapse, and the lump may be caused by the
parasite *Spirocerca*, for which F3D2F has tested positive (Karl Hill,
DVM, Santa Barbara Zoo, pers. comm.). Consequently, F3D2F may be treated
for *Spirocerca* in 2004.

Several males (75125, B4B2B, and D4C78) have injured females during the
breeding season. Those males have been removed from mating pens and
housed individually, and/or released to the wild, resulting in effective
loss of potential breeding pairs. One male fox thus released (75125)
subsequently paired up in the wild with another released captive fox
(95906). The pair was brought back into captivity because their use area
included the captive facilities, and are cohabiting in captivity without
further incident.

Foxes on Santa Rosa have more problems with ectoparasites (fleas and
ticks) than do San Miguel foxes. All foxes were treated with Frontline
(Merial Ltd., Athens, GA) during 2003 vet exams. All adult foxes
received both the initial and booster CDV vaccinations. No pups were
vaccinated.

### Future Management of Santa Rosa Captive Island Foxes

Of the 46 foxes in captivity, 19 are males, and there are 17 mated pairs
for the 2003-2004 breeding season, with 10 unmated females. Given past
reproductive rates, the 17 pairs for the upcoming breeding season are
likely to produce 15 pups, of which perhaps 8 will be females. The
captive population is likely to number at least 60 foxes by summer 2004
with perhaps 24 males and 36 females.

Capacity of the captive facility is 40 animals (20 breeding pens). If
eagle predation is sufficiently mitigated by fall 2004, another release
of Santa Rosa foxes to the wild may occur. But if eagle predation is not
sufficiently mitigated and the decision is made to keep foxes in
captivity, then either 10 additional pens must be built on the island,
or a portion of the captive breeding program must be moved to mainland
institutions.

## Status of Wild Fox Population

As of May 2004, there are 7 island foxes (1 male and 6 females) in the
wild on Santa Rosa Island, as a result of a recent reintroduction.
Twelve island foxes were released to the wild from December 2003 to
February 2004 (see Reintroduction of Santa Rosa Island Foxes, below).
Four were returned to captivity, and 1 died from eagle predation.

[]{#__RefHeading___Toc69872231 .anchor}Table 6. Reproductive success of
captive Santa Rosa Island foxes, 2002-2003 breeding season.

  -------- ------- ----- ----- ------------ ------------- ---------- -------- -------
  Pen      ID      Sex   Age   Paired       Result        Litter     Birth    
                                                          Size       Date     

  R02      D187A   F     5     10/19/2001   Litter        2          ≈April   
                                                                     6, 2003  

           0654E   M     3                                                    

  R03      2410E   F     3     10/17/2001   No Litter                         

           B4B2B   M     2                                                    

  R04      60B1D   F     2     10/24/2002   Litter        3          ≈April   
                                                                     9, 2003  

           53723   M     1                                                    

  R05      F0223   M     5                                                    

           F4A18   F     4     10/19/2000   No Litter                         

  R06      37E00   M     3                                                    

           37C61   F     3     10/19/2000   No Litter                         

  R07      10030   F     5     10/19/2000   No Litter                         

           70518   M     3                                                    

  R09      95B34   F     4     10/19/2000   No Litter                         

           84F28   M     3                                                    

  R10      33131   F     4     10/19/2000   No Litter                         

           A045A   M     3                                                    

  R11      3512D   F     5     11/05/2000   Litter        3          ≈April   
                                                                     6, 2003  

           73D0D   M     4                                                    

  R12      07061   F     5     10/24/2002   No Litter                         

           51E3E   M     1                                                    

  R14      E5100   F     3     1/17/2001    No Litter                         

           F3D2F   M     2                                                    

  R15      96C2E   F     2     11/17/2001   No Litter                         

           75125   M     2                                                    

  R16      B067E   M     5                                                    

           13C24   F     3     11/17/2001   No Litter                         

  R18      F3950   F     2     10/24/2002   No Litter                         

           7792E   M     1                                                    

  R19      1612C   F     4     11/17/2001   Litter        3          ≈April   
                                                                     6, 2003  

           D3D76   M     4                                                    

  R20      A180A   F     3     10/24/2002   No Litter                         

           1271E   M     1                                                    

  ^2^in                                                                       
  years,                                                                      
  as of                                                                       
  fall                                                                        
  2002                                                                        
  -------- ------- ----- ----- ------------ ------------- ---------- -------- -------

## Reintroduction of Santa Rosa Island Foxes

Because the success of further eagle removal remains uncertain, island
fox recovery may necessarily occur in an environment with eagles. Recent
estimates of annual fox survivorship on Santa Cruz Island exceeded that
required for a stable or increasing population, but it is unknown
whether survivorship of foxes released from captivity will equal that of
wild foxes, or if survivorship values will differ between islands. A
limited release of captive island foxes on Santa Rosa Island, coupled
with intense post-release monitoring, will indicate whether survivorship
of released foxes is acceptable under current conditions. If it is not,
then fox recovery will require either a greatly expanded captive
production, which may necessitate moving a portion of the captive
breeding program to the mainland, or other, more effective methods for
eagle removal.

To this end, captive foxes were experimentally released to the wild on
Santa Rosa Island in winter 2003-2004. The objectives of the release
were to:

• investigate survivorship of captive island foxes released to the wild,
under conditions of partial removal of golden eagles, and compare
survivorship to that of wild island foxes

• test release methods, and

• begin reestablishment of a wild population on Santa Rosa Island

Foxes selected for release were well-represented genetically in the
captive populations (Gray 2003, Gray et al. 2003). Foxes were released
as mated pairs that had been housed together for \>1 yr, as single
animals, or as groups of unpaired animals that had been placed together
in a socialization pen for 10-18 days. Foxes were outfitted with
radiotelemetry collars and were released directly from small portable
kennels. Feeding stations provided supplemental food, and foxes were
recaptured at intervals of 1 week and one month to determine physical
condition. Foxes were returned to captivity if they had lost \>20% of
their release weight. As a contingency for eagle predation, if ≥50% of
the released foxes die in the year after reintroduction (December 2003
to December 2004), the remaining released foxes will be recaptured and
returned to captivity.

From December 2003 to February 2004, 12 foxes were released to the wild
(Table 9). Released foxes comprised 3 juveniles (born in 2003), 3 1-year
olds, 2 2-year olds, 2 3-year olds, 1 4-year old, and 1 5-year old.
Three of the 12 animals were males. Four of the animals were released as
mated pairs. Foxes were released in 3 areas: Lobo Canyon, Arlington
Canyon, and Tecolote Canyon.

One released fox (female RF-101) died from eagle predation in February
2004. Upon detection of a mortality signal from her radiocollar, her
carcass was recovered in Trap Canyon, near a golden eagle nest site that
produced a chick in 2003. A golden eagle pair had initiated a breeding
attempt in the area, and was thought to be incubating at the site, until
they apparently abandoned in late March 2004 (B. Latta, Santa Cruz
Predatory Bird Research Group, unpubl. data).

Four released foxes (2 apparent pairs) were captured and returned to
captivity because they dispersed from their release areas to the captive
pen sites near Beecher's Bay (Fig. 4). Their use of the pen site areas
resulted in interactions between captive and wild foxes, and injuries to
2 captive and 2 wild foxes.

[]{#__RefHeading___Toc69872232 .anchor}Table 7. Release location, date,
release type and fate of foxes released to the wild on Santa Rosa
Island, winter 2003-2004.

+------+-----+---+---+--------+---------+-----------+---------------+
| PIT  | ID  | S | A | Date   | Release | Area      | Fate          |
| tag  |     | e | g |        | Type^1^ |           |               |
|      |     | x | e |        |         |           |               |
+------+-----+---+---+--------+---------+-----------+---------------+
| B    | R   | M | 5 | 11/2   | MP      | Lobo      | Returned to   |
| 067E | M-1 |   |   | 0/2003 |         | Canyon    | captivity     |
|      |     |   |   |        |         |           |               |
|      |     |   |   |        |         |           | 01/06/2004    |
+------+-----+---+---+--------+---------+-----------+---------------+
| 1    | RF- | F | 3 | 11/2   | MP      | Lobo      | Died 2/20/04  |
| 3C24 | 101 |   |   | 0/2003 |         | Canyon    | from          |
|      |     |   |   |        |         |           | predation     |
+------+-----+---+---+--------+---------+-----------+---------------+
| 4    | RF- | F | 1 | 11/2   | Gr      | Lobo      | Returned to   |
| 7304 | 102 |   |   | 1/2003 |         | Canyon    | captivity     |
|      |     |   |   |        |         |           |               |
|      |     |   |   |        |         |           | 01/30/2004    |
+------+-----+---+---+--------+---------+-----------+---------------+
| 9    | RF- | F | 1 | 11/2   | Gr      | Lobo      | Returned to   |
| 5906 | 103 |   |   | 1/2003 |         | Canyon    | captivity     |
|      |     |   |   |        |         |           |               |
|      |     |   |   |        |         |           | 02/08/2004    |
+------+-----+---+---+--------+---------+-----------+---------------+
| A    | RF- | F | J | 11/2   | Gr      | Lobo      | In wild       |
| 266D | 104 |   | u | 1/2003 |         | Canyon    |               |
|      |     |   | v |        |         |           |               |
|      |     |   | . |        |         |           |               |
+------+-----+---+---+--------+---------+-----------+---------------+
| 7    | R   | M | 2 | 12/0   | S       | Lobo      | Returned to   |
| 5125 | M-2 |   |   | 8/2003 |         | Canyon    | captivity     |
|      |     |   |   |        |         |           |               |
|      |     |   |   |        |         |           | 02/02/2004    |
+------+-----+---+---+--------+---------+-----------+---------------+
| 3    | RF- | F | 4 | 01/1   | MP      | Arlington | In wild       |
| 3131 | 106 |   |   | 7/2004 |         | Canyon    |               |
+------+-----+---+---+--------+---------+-----------+---------------+
| A    | R   | M | 3 | 01/1   | MP      | Arlington | In wild       |
| 045A | M-3 |   |   | 7/2004 |         | Canyon    |               |
+------+-----+---+---+--------+---------+-----------+---------------+
| 1    | RF- | F | J | 01/1   | Gr      | Tecolote  | In wild       |
| 4125 | 107 |   | u | 9/2004 |         | Canyon    |               |
|      |     |   | v |        |         |           |               |
|      |     |   | . |        |         |           |               |
+------+-----+---+---+--------+---------+-----------+---------------+
| 3    | RF- | F | 2 | 01/1   | Gr      | Tecolote  | In wild       |
| 4614 | 108 |   |   | 9/2004 |         | Canyon    |               |
+------+-----+---+---+--------+---------+-----------+---------------+
| 0    | RF- | F | 1 | 02/0   | Gr      | Tecolote  | In wild       |
| 1460 | 109 |   |   | 5/2004 |         | Canyon    |               |
+------+-----+---+---+--------+---------+-----------+---------------+
| A    | RF- | F | J | 02/0   | Gr      | Tecolote  | In wild       |
| 7954 | 110 |   | u | 5/2004 |         | Canyon    |               |
|      |     |   | v |        |         |           |               |
|      |     |   | . |        |         |           |               |
+------+-----+---+---+--------+---------+-----------+---------------+
| ^    |     |   |   |        |         |           |               |
| 1^MP |     |   |   |        |         |           |               |
| =    |     |   |   |        |         |           |               |
| m    |     |   |   |        |         |           |               |
| ated |     |   |   |        |         |           |               |
| pair |     |   |   |        |         |           |               |
|      |     |   |   |        |         |           |               |
| Gr = |     |   |   |        |         |           |               |
| G    |     |   |   |        |         |           |               |
| roup |     |   |   |        |         |           |               |
|      |     |   |   |        |         |           |               |
| S =  |     |   |   |        |         |           |               |
| si   |     |   |   |        |         |           |               |
| ngle |     |   |   |        |         |           |               |
| an   |     |   |   |        |         |           |               |
| imal |     |   |   |        |         |           |               |
+------+-----+---+---+--------+---------+-----------+---------------+

The 2 released pairs did not stay together in the wild. The male from
the first pair released (RM-1) began associating with a female (RF-102)
from a group released the following day. The 2 were brought into
captivity in January due to impacts on captive foxes, and are housed
together because of the potential pair bond that may have formed.
Radiotelemetry tracking suggests that the male from the second released
pair (RM-3) may have paired up in the wild with female RF-108. Also, the
single male released (RM-2) appeared to pair up in the wild with female
RF-103. The pair was brought back into captivity in February because
their use area included the captive breeding pen sites.

Most released foxes dispersed from their release sites and established
use areas elsewhere. Two foxes dispersed significantly from their
release site in Tecolote Canyon (Fig. 4). Female RF-109 moved 7.2 km
from the release site to a location near China Camp on the southwest
coast, and female RF-109 moved 15.2 km from the release site to an area
on the southeast coast.

![](media/image6.wmf){width="6.280555555555556in"
height="4.853472222222222in"}

# Recovery of Santa Cruz Island Foxes

## Captive Breeding

The primary Santa Cruz Island facility was constructed in February 2002
and consists of 10 pens spread along Renegade Ridge near the Navy site
(Fig. 4). The Nature Conservancy is currently building a second facility
of 10 pens in the Central Valley. There are currently 10 pairs and a
total of 25 foxes in captivity on Santa Cruz Island (Table 9).

Of the 10 pairs in the facility for the 2002-2003 breeding season, 5
produced litters, and 10 pups were born (Table 10). A total of 9 foxes
from the facility were released to the wild in December 2003 (see
Reintroduction of Foxes to the Wild, below). Five of the 9 were killed
by golden eagles within several weeks of release, and so the remaining 4
were returned to captivity.

![](media/image7.wmf){width="5.895833333333333in"
height="4.555555555555555in"}

### Health/Medical

Captive Santa Cruz Island foxes received veterinary examinations from
project veterinarian Mark Willet, DVM, in June 2003. Routine general
physical examinations were performed in a nose to tail fashion, and
included otoscopic examination. Blood samples were obtained from all
animals for complete blood chemistry analysis. Foxes were generally in
good or excellent health, although all required treatment for
ectoparasites. All captive adult animals on Santa Cruz received initial
and booster CDV vaccinations. One male (D0926) was separated from his
penmate because he had injured her repeatedly. He was released to the
wild in November 2003 and then recaptured and brought into captivity in
January 2004. He is now housed individually. The injured female, 16C30,
has been paired with male F3F0E.

[]{#__RefHeading___Toc69872233 .anchor}Table 8. Reproductive success of
captive Santa Cruz Island foxes, 2002-2003 breeding season.

  --------- -------- --------- ------------ ------------ ------------ ------------ ------------
  **Pen**   **ID**   **Sex**   **Age^1^**   **Paired**   **Result**   **Litter     **Birth
                                                                      Size**       Date**

  C01       A4628    M         6                                                   

            30B2D    F         4            3/11/2002    Litter       2            unknown

  C02       D2C13    F         3            3/1/2002     Litter       2            unknown

            A6D41    M         3                                                   

  C03       0786F    F         5            3/3/2002     NL           0            

            1415A    M         3                                                   

  C04       B506A    M         3                                                   

            C5D0E    F         3            1/15/2003    NL           0            

  C05       36172    M         4                                                   

            72901    F         3            2/27/2002    NL           0            

  C06       86F17    F         3            3/10/2002    Litter       2            ≈April 12,
                                                                                   2003

            86B1A    M         3                                                   

  C07       45411    M         3                                                   

            D2210    F         2            3/11/2002    Litter       2            unknown

  C08       16C30    F         2            11/1/2002    NL           0            

            D0926    M         1                                                   

  C09       1783E    M         6                                                   

            87035    F         5            12/4/2002    Litter       2            unknown

  C10       C002B    M         1                                                   

            73863    F         1            10/4/2002    NL           0            

  ^1^In                                                                            
  years, as                                                                        
  of fall                                                                          
  2002                                                                             
  --------- -------- --------- ------------ ------------ ------------ ------------ ------------

### Future Management of Santa Cruz Island Captive Foxes

The 10 pairs currently in captivity are likely to produce 10 pups in
spring 2004, putting the captive population at 35 animals, and
essentially filling the captive facility. If foxes cannot be released to
the wild in fall 2004 because of the threat of eagle predation, then
additional pens must be built to accommodate captive production in
spring 2005, or a portion of the breeding program must be moved to the
mainland.

## Status of Wild Fox Population

Results from island-wide trapping efforts in 2001 and 2001 suggest that
the Santa Cruz Island fox wild population may be stable, but not
increasing. Island fox trapping success in 2002 (14.6%) was nearly
identical to that in 2001 (17.7%), and similar number of individuals
were caught in 2002 (70 adults, 27 pups) as in 2001 (75 adults, 32 pups)
(Dennis et al. 2002, Newman et al. 2003).

## Reintroduction of Santa Cruz Island Foxes

Because the success of further eagle removal remains uncertain, island
fox recovery may necessarily occur in an environment with eagles. Recent
estimates of annual fox survivorship on Santa Cruz Island approached
that required for a stable or increasing population, but it is unknown
whether survivorship of foxes released from captivity will equal that of
wild foxes, or if survivorship values will differ between islands.

An experimental release of captive foxes to the wild on Santa Cruz
Island occurred in November-December 2003. The purpose of the release
was to:

• investigate survivorship of captive island foxes released to the wild,
under conditions of partial removal of golden eagles, and compare
survivorship to that of wild island foxes, and

• test release methods

Foxes were released as mated pairs which had been housed together for
\>1 yr, as single animals, or as groups of unpaired animals which had
been placed together in a socialization pen for 10-18 days. Foxes were
outfitted with radiotelemetry collars and were released directly from
small portable kennels. Feeding stations provided supplemental food, and
foxes were recaptured at intervals of 1 week and one month to determine
physical condition. Foxes were returned to captivity if they had lost
\>20% of their release weight. As a contingency for eagle predation, if
radiotelemetry monitoring indicated that ≥50% of the released foxes died
in the year after reintroduction (November 2003 to November 2004), the
remaining released foxes would be recaptured and returned to captivity.

Two releases occurred on Santa Cruz Island in 2003. A mated pair and a
single male were released in Coches Prietos Canyon in November, and 6
unmated foxes were released in the Del Norte area in December (Table 7).
The Del Norte release comprised 2 groups of 3 animals, each of which had
been housed together in a socialization pen prior to the release.

Five of the 9 released foxes died from eagle predation within 2 months
of release. Because this met the contingency threshold for eagle
predation, the remaining 4 released animals were recaptured and brought
back into captivity in early January.

The 5 mortalities all occurred within a period of 13 days, and it is
possible that 1 golden eagle was responsible for all 5 mortalities (B.
Latta, Santa Cruz Predatory Bird Research Group, pers. comm.). On
January 20, 2004, SCPBRG staff captured the male from the Cascada pair
of adult golden eagles. The Cascada male may have been responsible for
the mortalities of the released foxes, because they all occurred in the
territory of the Cascada eagle.

The high predation rate on released foxes stands in marked contrast to
the lower predation rate on wild foxes on Santa Cruz Island (see Impact
of Eagle Predation on Island Foxes, below). Released foxes may be more
vulnerable to predation for any of a number of reasons. First, wild
foxes may be more nocturnal than foxes released from captivity. Diurnal
activity patterns of released foxes may expose them more to golden eagle
predation. Second, released foxes may utilize cover less than wild
foxes. Third, released foxes may move more than wild foxes. The latter
generally have established home ranges and many are members of mated
pairs. Movements of released foxes away from release sites, to acquire
mates and establish home ranges or use areas, may expose them more to
predation.

Given the high predation rate on released foxes, release of foxes from
captivity is unlikely to be an effective recovery action on Santa Cruz
Island until the predation environment changes considerably.

[]{#__RefHeading___Toc69872234 .anchor}Table 9. Release location, date,
release type and fate of foxes released to the wild on Santa Cruz
Island, December 2003.

+------+-----+---+---+--------+---------+-----------+---------------+
| PIT  | ID  | S | A | Date   | Release | Area      | Fate          |
| tag  |     | e | g |        | Type^1^ |           |               |
|      |     | x | e |        |         |           |               |
+------+-----+---+---+--------+---------+-----------+---------------+
| D    | M87 | M | 1 | 11/2   | S       | Coches    | Returned to   |
| 0926 |     |   |   | 1/2003 |         | Prietos   | captivity     |
|      |     |   |   |        |         |           | 01/08/2004    |
+------+-----+---+---+--------+---------+-----------+---------------+
| C    | M60 | M | 1 | 11/2   | MP      | Coches    | Died          |
| 002B |     |   |   | 1/2003 |         | Prietos   | 01/01/2004    |
|      |     |   |   |        |         |           | from          |
|      |     |   |   |        |         |           | predation     |
+------+-----+---+---+--------+---------+-----------+---------------+
| 7    | F82 | F | 1 | 11/2   | MP      | Coches    | Died          |
| 3863 |     |   |   | 1/2003 |         | Prietos   | 01/01/2004    |
|      |     |   |   |        |         |           | from          |
|      |     |   |   |        |         |           | predation     |
+------+-----+---+---+--------+---------+-----------+---------------+
| 0    | F88 | F | J | 12/0   | Gr      | Del Norte | Returned to   |
| 1C77 |     |   | u | 9/2003 |         |           | captivity     |
|      |     |   | v |        |         |           | 01/05/2004    |
|      |     |   | . |        |         |           |               |
+------+-----+---+---+--------+---------+-----------+---------------+
| E    | F87 | F | J | 12/0   | Gr      | Del Norte | Returned to   |
| 250C |     |   | u | 9/2004 |         |           | captivity     |
|      |     |   | v |        |         |           | 01/05/2004    |
|      |     |   | . |        |         |           |               |
+------+-----+---+---+--------+---------+-----------+---------------+
| A    | M92 | M | 1 | 12/0   | Gr      | Del Norte | Died          |
| 1570 |     |   |   | 9/2004 |         |           | 01/03/2004    |
|      |     |   |   |        |         |           | from          |
|      |     |   |   |        |         |           | predation     |
+------+-----+---+---+--------+---------+-----------+---------------+
| F    | M91 | M | J | 12/0   | Gr      | Del Norte | Returned to   |
| 3F0E |     |   | u | 9/2004 |         |           | captivity     |
|      |     |   | v |        |         |           | 01/05/2004    |
|      |     |   | . |        |         |           |               |
+------+-----+---+---+--------+---------+-----------+---------------+
| E    | F90 | F | J | 12/0   | Gr      | Del Norte | Died from     |
| 3564 |     |   | u | 9/2004 |         |           | 12/27/2003    |
|      |     |   | v |        |         |           | predation     |
|      |     |   | . |        |         |           |               |
+------+-----+---+---+--------+---------+-----------+---------------+
| 3    | F89 | F | J | 12/0   | Gr      | Del Norte | Died          |
| 7F3A |     |   | u | 9/2004 |         |           | 12/21/2003    |
|      |     |   | v |        |         |           | from          |
|      |     |   | . |        |         |           | predation     |
+------+-----+---+---+--------+---------+-----------+---------------+
| ^    |     |   |   |        |         |           |               |
| 1^MP |     |   |   |        |         |           |               |
| =    |     |   |   |        |         |           |               |
| m    |     |   |   |        |         |           |               |
| ated |     |   |   |        |         |           |               |
| pair |     |   |   |        |         |           |               |
|      |     |   |   |        |         |           |               |
| Gr = |     |   |   |        |         |           |               |
| G    |     |   |   |        |         |           |               |
| roup |     |   |   |        |         |           |               |
|      |     |   |   |        |         |           |               |
| S =  |     |   |   |        |         |           |               |
| si   |     |   |   |        |         |           |               |
| ngle |     |   |   |        |         |           |               |
| an   |     |   |   |        |         |           |               |
| imal |     |   |   |        |         |           |               |
+------+-----+---+---+--------+---------+-----------+---------------+

# Removal of Golden Eagles

Staff from the Santa Cruz Predatory Bird Research Group (SCPBRG)
continued their efforts to remove golden eagles via bownet or other
live-capture method in 2003. A total of 9 golden eagles was removed from
the islands in 2003. An additional eagle (the Cascada male) was trapped
and relocated in early 2004, bringing the total removed since 1999 to 32
eagles. In 2003 golden eagles were observed breeding on Santa Rosa
Island, where they apparently are supported by the herds of non-native
mule deer and elk. As many as 14 eagles remained on the islands as of
early 2004 (Fig. 6).

In 1999 NPS established a cooperative agreement with the SCPBRG for
relocation of golden eagles from the northern Channel Islands. The
primary technique used has been a dug-in, radio-controlled bownet placed
in areas that eagles frequented (Jackman et al. 1994). Bait used
included dead feral pigs, live feral pigs, and live rabbits. The bownet
was set in place prior to dawn. If an eagle alighted on the prey, the
net was deployed via radio signal from a distant hidden observation
point. Captured eagles were banded and measured, and transported in
large commercial sky kennels modified for raptor transport. Most eagles
were driven to the airstrip and flown off the island by the next
morning, and then driven or flown by commercial airliner and driven to
one of several release sites, east of the Sierra Nevada range. Releases
occurred usually within 24 hours of capture.

Of the 9 eagles captured in 2003, 6 were captured at a carrion chum site
set up for juvenile bald eagles in the China Pines area of Santa Cruz
Island. Only 1 of 4 known territorial birds, the male from the Trap
Canyon territory on Santa Rosa Island, was captured. Two eyases
(hatchlings) were removed from nests by hand, 1 from the Trap Canyon
nest and 1 from the Cascada nest on Santa Cruz Island.

For the first time, golden eagles were recorded breeding on Santa\
Rosa Island. A pair bred at Trap Canyon (Fig. 6), producing a chick that
was removed by hand in June and hacked out on the mainland in northern
California. Another pair began a nesting attempt in the Trancion Canyon
area but abandoned the attempt in March. Post-nesting examination of the
nests revealed several nests in each territory, with several distinct
layers, indicating golden eagles have bred on Santa Rosa, undiscovered,
since as early as 1997. This is further supported by the presence of
island fox remains in the lower levels; foxes were last extant on the
island in 2000.

Prey remains of numerous birds and mammals were found in the Santa Rosa
nests. Because golden eagles only deliver prey to nests with hatchlings,
the presence of prey remains represent the prey delivered during the
hatchling phase of nesting (April, May and June), and also indicates
successful breeding (production of at least 1 chick) in those years.
Avian remains included gulls, cormorants, ravens, and meadowlarks.
Mammalian prey included foxes, skunks, and mule deer fawns. The latter
were not present in every layer, but mule deer fawns in some years
apparently provide golden eagles with the small portable prey required
for raising chicks. Moreover, carcasses from deer and elk are readily
available from August through November on Santa Rosa Island, due to the
annual hunt and cull that occurs during that time period. The carcasses
are a food source for golden eagles during the period when they are
garnering the energetic resources required for breeding.

![](media/image8.wmf){width="6.379861111111111in"
height="4.479166666666667in"}

Up to 8 nests were observed on the north slope of Santa Cruz Island
during a helicopter survey. The nests were discovered in an area not
heretofore known as a possible breeding territory. Both the north slope
territory on Santa Cruz Island and the Trap Canyon territory on Santa
Rosa Island may be a source of many of the golden eagles observed on the
islands since 1999.

By the end of 2003 there were as many as 14 golden eagles on Santa Cruz
and Santa Rosa Islands (Fig. 6), including 4 potential pairs of breeding
adults. Intensive live-capture operations are planned for spring and
summer 2004.

## Impact of Eagle Predation on Island Foxes 

A radiotelemetry study conducted on Santa Cruz Island since 2002
provides evidence that although eagle predation is ongoing, annual
survival of wild island foxes has increased during the period of eagle
removal, and is at or above 80%, the target identified by demographic
modeling as necessary for a stable or increasing population. However,
eagle predation on foxes released to the wild from captivity on Santa
Cruz Island is substantially higher.

[]{#__RefHeading___Toc69872235 .anchor}Table 10. Cause of mortality for
radiocollared foxes on Santa Cruz Island, December 2000 to April 2004.

  --------- ------------- -------- --------- --------- ------------ ------------------
  **No.**   **Date**      **ID**   **Sex**   **Age**   **Status**   **Mortality
                                                                    Cause**

  1         3/23/2001     M5       M         1         Wild         Predation

  2         5/23/2001     F7       F         A         Wild         Predation

  3         6/1/2001      F1       F                   Wild         Predation

  4         6/13/2001     M13      M         4         Wild         Predation

  5         8/24/2001     M23      M         1         Wild         Predation

  6         9/29/2001     F4       F         2         Wild         Predation

  7         11/16/2001    M17      M         1         Wild         Predation

  8         11/17/2001    F11      F         1         Wild         Predation

  9         11/17/2001    M4       M         1         Wild         Septicemia

  10        3/3/2002      F36      F         1         Wild         Predation

  11        3/28/2002     M12      M         2         Wild         Predation

  12        4/11/2002     M19      M         1         Wild         Predation

  13        8/16/2002     M11      M         3         Wild         Undetermined

  14        11/9/2002     M15      M         1         Wild         Blunt trauma

  15        12/17/2002    M68      M         0         Captive      Predation

  16        12/20/2002    M70      M         0         Captive      Predation

  17        1/23/2003     F39      F         1         Wild         Predation

  18        1/31/2003     M49      M         1         Wild         Predation

  19        4/10/2003     M6       M         2         Wild         Predation

  20        11/14/2003    F45      F         3         Wild         Predation

  21        12/3/2003     F2       F         4         Wild         Septicemia

  22        12/22/2003    F89      F         0         Captive      Predation

  23        12/25/2003    F90      F         0         Captive      Predation

  24        1/1/2004      M60      M         1         Captive      Predation

  25        1/1/2004      F82      F         1         Captive      Predation

  26        1/3/2004      M92      M         0         Captive      Predation

  27        2/7/2004      F65      F         1         Wild         Predation

  28        2/22/2004     F80      F         1         Wild         Predation

  29        3/15/2004     F62      F         1         Wild         Predation
  --------- ------------- -------- --------- --------- ------------ ------------------

Since December 2000, the Institute for Wildlife Studies, with funding
from The Nature Conservancy, has been conducting a study of mortality
factors for island foxes on Santa Cruz Island. The Institute has
maintained a standing sample of approximately 25 radiocollared island
foxes, though the number of collars was increased to over 60 in January
2004. Radiocollared animals are checked for mortality status several
times per week. Upon receipt of a mortality signal, the carcass is
recovered and sent to the Veterinary Medical Teaching Hospital at
University of California, Davis, for necropsy. Physical evidence of
predation by golden eagles includes degloving of limbs, removal of
viscera, talon holes, and hemorrhaging (Roemer et al. 2001a).

From December 2000 to April 2004, 29 radiocollared foxes died, and
golden eagle predation was identified as the cause of mortality for 25
(86%) of the 29 foxes (Table 10). Other causes of mortality included
septicemia resulting from a necrotic prolapsed rectum, which may have
been caused by infection with the parasite *Spirocerca* (fox no. 21).
Another fox (no. 9) died from septicemia that may have arisen from
infection of a *Spirocerca* lesion in the colon. One fox (no. 14) died
from blunt trauma when the snag under which he had been resting
apparently collapsed, perhaps during heavy precipitation. In one fox the
cause of death could not be determined because of the advanced
decomposition of the carcass.

Seven of the 29 foxes were animals released from captivity, and their
mortalities occurred within several weeks of release. In 2002, 2 of 3
foxes released to the wild from captivity subsequently died from eagle
predation. In 2003/2004, 5 of 9 foxes released from captivity were
killed by eagles within several weeks of release. All of the released
animals that died were juveniles (young of the year) or yearlings (1.5
yrs old).

To compare the high predation rate on released captive foxes with that
on wild foxes, we estimated annual survivorship of wild foxes with a
staggered entry, Kaplan-Meier procedure (Pollock et al. 1989). Under
this procedure, survivorship starts out at 100% and declines with each
successive mortality. For each month beginning in January 2002, we
estimated survivorship for the previous 12 months, and so compiled
rolling annual survivorship over the study period. Annual survivorship
increased over the study period from approximately 60% to over 80% (Fig.
7), perhaps due to the removal of 27 adult, subadult and juvenile golden
eagles during the period.

In comparison, fox survivorship in 1993-1994 on Santa Cruz Island, prior
to the decline, was over 80%, but declined to 39% the following year due
to eagle predation (Roemer et al. 2001a). Island fox survivorship on San
Miguel Island in 1998-1999, prior to bringing foxes into captivity, was
12% (Coonan et al. in review). Thus, current survivorship on Santa Cruz
Island is greater than that recorded during the island fox population
decline.

Annual survivorship of at least 80% is necessary for recovery of island
fox populations (Roemer et al. 2001b). Demographic modeling shows that a
Santa Cruz island fox population with 80% annual survivorship has a
\>99% chance of recovering to carrying capacity, but a population with
70% survivorship never increases beyond the current low level of 75
foxes, and has a 50% chance of going extinct (T. Coonan, National Park
Service, unpubl. data).

The high predation rate on released Santa Cruz Island foxes stands in
contrast with the initial survival of island foxes released to the wild
on Santa Rosa Island. On that island, 12 foxes were released from
captivity from December 2003 to February 2004. Four were returned to
captivity (see Reintroduction of Santa Rosa Island Foxes under Recovery
of Santa Rosa Island Foxes, above) and 1 was killed by golden eagles in
January 2004.

If these survival rates hold, it may be advisable to continue releases
in fall 2004 on Santa Rosa Island, and begin initial releases on San
Miguel Island. However, it is possible that predation on Santa Rosa
released foxes will increase in the near future, and that the
contingency threshold of 3 additional fox predation mortalities will be
reached. If that happens, the remaining foxes would be trapped and
returned to captivity, and subsequent releases would necessarily await a
substantial change in the eagle predation environment.\
![](media/image9.wmf){width="5.990277777777778in"
height="4.108333333333333in"}

# Other Actions Required for Recovery

The immediate actions required for island fox recovery are captive
breeding of island foxes and removal of golden eagles. Additional,
longer term actions required for island fox recovery include removal of
pigs from Santa Cruz Island, and reintroduction of bald eagles to the
northern Channel Islands (Coonan 2003). The former is required to remove
an alien prey base that supports golden eagle use of the islands, and
the latter is required to return bald eagles to their former role as
apex predator in the system. It is hoped that breeding bald eagles may
deter future golden eagle use of the islands.

An additional action required is to assemble an island fox recovery team
that can effectively assist the management agencies in making decisions
about island fox recovery efforts. Difficult decisions are on the
immediate horizon. Predation rates on released foxes are high, captive
fox populations have grown to facility capacities on all islands, and up
to 14 golden eagles still exist on the islands. Island fox management
decisions, such as whether to release foxes in fall 2004, are thus
complicated, and technical assistance from a fox recovery team is
essential to informing such decisions.

## Removal of Feral Pigs from Santa Cruz Island

Environmental compliance and planning for the removal of feral pigs from
Santa Cruz Island is now complete (NPS 2002), and funding has been
secured from the NPS and The Nature Conservancy. A contractor is
currently being selected and pig removal should begin in summer 2004.
Removal of pigs should be completed within 2-4 years, and the majority
of the pigs may be removed very quickly, perhaps within 1-2 years.

Demographic modeling of pig, fox and golden eagle populations (Courchamp
et al. 2003) suggests that as the pig population declines due to
removal, golden eagles may switch to preying on foxes and drive the
remaining wild foxes to extinction. However, such accelerated predation
might not occur, because eagles take many other prey besides pigs and
foxes on the Channel Islands, and thus there may not be one-for-one
switching from pigs to foxes (B. Latta, Santa Cruz Predatory Bird
Research Group, personal communication). Additionally, pigs have
fluctuated markedly in the past, perhaps from lows of less than 1,000
pigs to highs of greater than 5,000 pigs (R. Klinger, University of
California, Davis, unpubl. data) without driving foxes to extinction.
Since 2000, predation rates on foxes are more related to the number of
eagles present than the number of pigs present (T. Coonan, National Park
Service, unpubl. data). That is, as the number of eagles removed has
increased, and the number of eagles remaining has decreased, survival of
wild island foxes has increased (see Impact of Eagle Predation on Island
Foxes, above).

Though the model may have more heuristic than predictive power, the
conservative approach is to attempt to detect such an effect, and
mitigate it. To detect such an effect in a timely fashion, The Nature
Conservancy has funded an expansion of the current island fox
radiotelemetry study on Santa Cruz Island. As of January 2004 the number
of radiocollared foxes in the study had increased from the previous
standing sample of 20-25 foxes to over 60 foxes (D. Garcelon, Institute
for Wildlife Studies, unpubl. data). If predation increases
significantly due to pig removal, then appropriate mitigation would
comprise capturing and bringing into captivity additional island foxes.

## Reintroduction of Bald Eagles to Santa Cruz Island

In 2002, the Institute for Wildlife Studies began a feasibility study to
determine if bald eagles could be successfully reintroduced to the
northern Channel Islands. The study is funded by settlements monies from
the Montrose Settlements Restoration Program (NOAA et al. 2002), because
the disappearance of bald eagles from the Channel Islands in the
mid-2oth century was due to the effects of organochlorine contaminants
in the marine ecosystem of southern California. As of spring 2004 there
were a total of 15 juvenile bald eagles on the northern Channel Islands,
as a result of reintroductions in summer 2002 and summer 2003.

The goal of the study is to release up to 12 juvenile bald eagles
annually on the northern Channel Islands for 5 years, and to monitor
released eagles and their prey for contaminant levels to determine if
levels are sufficiently low to allow breeding. Twelve juvenile eagles
were released from hack towers on Santa Cruz Island in 2002, and 11 in
2003. Because bald eagles mature at 4-5 years of age, birds from the
first (2002) release group may begin breeding in 2006 or 2007. As of
spring 2004, 7 eagles from the 2002 release and 8 released in 2003 were
alive on the islands (Garcelon 2004). Two released birds dispersed to
the mainland and are currently in Utah and Oregon, respectively. The
remaining 6 eagles died, likely from attempting to cross the Santa
Barbara Channel.

Bald eagles from both release years have been recorded on Santa Rosa
Island during late fall and winter. Released bald eagles have been
observed feeding on carcasses and gut piles from the commercial hunt and
annual cull of mule deer and elk on that island.

## Establishment of Island Fox Recovery Team

On March 1, 2004, the U.S. Fish and Wildlife Service listed the island
fox subspecies on San Miguel, Santa Rosa, Santa Cruz and Santa Catalina
Islands as endangered (USFWS 2004). Now that the 4 subspecies are
listed, the Service is in the process of assembling an island fox
recovery team. Although many typical recovery teams are convened in
order to develop a recovery plan for a particular species, the Service
recognizes that island fox recovery actions are well under way, and are
guided by an island fox recovery strategy document that is akin to a
recovery plan. The Service also recognizes the contributions toward
island fox recovery made by the Island Fox Conservation Working Group
and its members. Accordingly, the recovery team that is being assembled
will utilize the expertise existing in the Working Group, and will
insure continued participation by those experts. Moreover, the focus of
the recovery team will be less on development of a recovery plan, and
more on providing the management agencies with the technical expertise
required for informed island fox decision-making.

An overall recovery coordination group will assign technical questions
to a number of technical advisory groups. Upon receipt of results from
the technical advisory group, the coordination team will pass on
recommendations to the management agencies. Thus the overall effort will
be similar to the current function of the existing Island Fox
Conservation Working Group.

Examples of issues to be addressed by technical advisory groups include
the following:

-   How could mate-choice be incorporated into selection of pairs for
    breeding?

-   What are the consequences for San Miguel Island fox recovery of the
    male-biased sex ratio in captive pups produced on that island?

-   How can mainland zoos accommodate island foxes, if we need to move a
    portion of captive breeding to the mainland this fall? Would a
    research colony be preferable to holding island foxes in zoos?

-   Given current number of eagles on the islands, and current predation
    rates on wild and reintroduced foxes, how successful must eagle
    removal be this spring to allow for additional fox releases next
    fall?

-   What are the mitigation measures that must be implemented in order
    for foxes to go the mainland and back without transferring pathogens
    to mainland zoos, or back to wild island foxes?

-   What reintroduction methods should be used for island foxes?

-   What caretaking/veterinary procedures should island fox caretakers
    implement (development of an island fox caretaker handbook)?

-   How can island fox genetic and studbook (pedigree) data be used
    efficiently to choose animals for matings, for release to the wild,
    and for relocation to mainland institutions?

-   Given whatever success the current intensive eagle removal achieves,
    what methods and level of effort should eagle management have in the
    next capture season, and beyond?

-   How should wild island fox populations, and island foxes released to
    the wild, be monitored?

-   How and where should island fox biological samples (blood and
    tissue) be stored for future analysis? Can a central repository be
    established?

# Budget

A total of approximately \$816,000 was spent on island fox recovery on
the northern Channel Islands in fiscal year 2003 (Table 11), and a
variety of funding sources contributed to the effort. Captive breeding
costs totaled approximately \$467,422, and included the costs of island
fox care on 3 islands. National Park Service monies from the Natural
Resource Preservation Program and the 20% Fee Demonstration program
comprised the largest single funding sources, at \$237,000 and
\$258,000, respectively. Overall, National Park Service funds accounted
for \$643,000 (79%) of the effort. The Nature Conservancy continued its
support of the wild fox survivorship project on Santa Cruz Island, and
funded fox caretaking for the captive breeding facility on that island.

[]{#__RefHeading___Toc69872236 .anchor}Table 11. Costs and funding
sources for island fox recovery actions, fiscal year 2003 (1 October
2002 to 30 September 2003).

  -------------------- ----------- ---------- ------------ --------- -----------
  **Fiscal Year 2003** **NPS 20%   **NPS      **NPS        **TNC**   **Total**
                       Fee**       NRPP**     Parkbase**             

                                                                     

  Program Coord.                              86,447                 86,447

                                                                     

  Captive Breeding                                                   

  Personnel            63,888      133,609    65,000       48,000    310,497

  Island perdiem       8,686       19,044                            27,730

  Flights              20,290      11,867                            32,157

  Fox food             7,110       9,745                             16,855

  Supplies/equipment   8,630       49,404                            58,034

  Vet care             17,465                                        17,465

  Vet tests            3,708                                         3,708

  Vet supplies         996                                           996

  Total Captive        130,773     223,669    65,000       48,000    467,442
  Breeding                                                           

                                                                     

  Eagle Removal        126,917                             25,000    151,917

  SCI fox monitoring                                       100,000   100,000

  Island Fox Meeting               10,000                            10,000

                                                                      

  TOTAL                257,690     233,669    151,447      173,000   815,806
  -------------------- ----------- ---------- ------------ --------- -----------

## Future Costs

Estimated costs for island fox recovery actions in fiscal year 2004
total over \$1,000,000 (Table 12). The substantial increase from
recovery costs in previous years is primarily due to the intensive
live-capture operation for removal of golden eagles, scheduled for
spring 2004. Additional expenses include costs for building perimeter
fences around captive facilities on Santa Rosa and San Miguel Islands,
to prevent interactions between captive and wild foxes, as well as the
costs of testing sperm quality in male island foxes on Santa Cruz and
Santa Rosa Islands.

Available funding sources include remaining monies from the 20% Fee
Demonstration project, settlement monies from environmental contaminant
cases, the second year of a Natural Resource Preservation Program
project, and substantial funding from The Nature Conservancy.

[]{#__RefHeading___Toc69872237 .anchor}Table 12. Estimated costs and
funding sources for island fox recovery actions on the northern Channel
Islands, fiscal year 2004.

  -------------------- ---------- ------------ --------- --------- ---------- --------- -----------
  Fiscal Year 2004     Fox        NPF          NPS 20%   NPS NRPP  NPS        TNC       Total
                       Donation   Settlement   Fee Demo            Parkbase             
                       Account                                                          

                                                                                        

  Program Coord.                                                   90,337               90,337

                                                                                        

  Captive Breeding                                                                      

  Personnel                                    102,741   160,690              48,000    311,431

  Island perdiem                                         26,861                         26,861

  Flights                                                35,216                         35,216

  Fox food                                               29,387                         29,387

  Supplies/equipment                                     42,742                         42,742

  Perimeter fencing    20,000                                                           20,000

  Repr. Testing                                          3,000                          3,000

  Vet care             12,542                                                           12,542

  Vet tests                                              11,024                         11,024

  Vet supplies                                           1,082                          1,082

  Total Captive        32,542     0            102,741   310,002   0          48,000    493,286
  Breeding                                                                              

                                                                                        

  Eagle Removal                   75,000                 17,920               375,000   467,920

  SCI fox monitoring                                                          100,000   100,000

  Island Fox Meeting                                     10,000                         10,000

                                                                                         

  TOTAL                32,542     75,000       102,741   337,922   90,337     523,000   1,161,542
  -------------------- ---------- ------------ --------- --------- ---------- --------- -----------

# Literature Cited

American Society of Mammalogists. 1987. Acceptable field methods in
Mammalogy: preliminary guidelines approved by the American Society of
Mammalogists. ad hoc Committee on Acceptable Field Methods in Mammalogy.
Journal of Mammalogy 68:1-18.

Collins, P. W. 1993. Taxonomic and biogeographic relationships of the
island fox (*Urocyon littoralis*) and gray fox (*U. cinereoargenteus*)
from Western North America. Pages 351-390 in Hochberg, F. G., (ed.),
Third California Islands Symposium: Recent Advances in Research on the
California Islands. Santa Barbara Museum of Natural History, Santa
Barbara, California. 661 pp.

Coonan, T. J., C. A. Schwemm, G. W. Roemer, D. K. Garcelon, and L.
Munson. In review. Decline of island foxes to near extinction on San
Miguel Island, California. Submitted to Southwestern Naturalist.

Coonan, T. J. 2003. Recovery strategy for island foxes (*Urocyon
littoralis*) on the northern Channel Islands. National Park Service,
Ventura, California. 81 pp.

Courchamp, F., R. Woodroffe, and G. Roemer. 2003. Removing protected
populations to save endangered species. Science (302):1532.

Coonan, T., and K. Rutz. 2001. Island fox captive breeding program,
1999-2000 annual report. Technical Report 01-01. National Park Service.
38 pp.

Coonan, T., and K. Rutz. 2002. Island fox captive breeding program, 2001
annual report. Technical Report 02-01. National Park Service. 55 pp.

Coonan, T., and K. Rutz. 2003. Island fox captive breeding program, 2002
annual report. Technical Report 03-01. National Park Service. 52 pp.

Coonan, T. J., C. A. Schwemm, G. W. Roemer, and G. Austin. 2000.
Population decline of island foxes (*Urocyon littoralis littoralis*) on
San Miguel Island. Pages 289-297 in Browne, D. K., K. L. Mitchell, and
H. W. Chaney, (eds.), Proceedings of the 5th California Islands
Symposium. U.S. Department of the Interior, Minerals Management Service,
Pacific OCS Region.

Dennis, M., K. Randall, G. Schmidt, and D. Garcelon. 2002. Island fox
(*Urocyon littoralis santacruzae*) distribution, abundance and survival
on Santa Cruz Island, California. Progress report: for work conducted
between 08 Feb 2002 and 31 Mar. 2002. Institute for Wildlife Studies,
Arcata, California. 24 pp.

Garcelon, D. K. 2004. Bald eagle restoration on the northern Channel
Islands, California, May 2003-December 2003, 2^nd^ annual report.
Unpublished manuscript on file at park headquarters, Channel Islands
National Park, Ventura, California.

Georgi, J. V., and M. E. Georgi. 1991. Canine clinical parasitology. Lea
and Febiger, Philadelphia. 227 pp.

Gray, M. M. 2003. Relatedness of Santa Cruz captive population and
female 07061 within the Santa Rosa captive population. Unpublished
report on file at park headquarters, Channel Islands National Park,
Ventura, California. 16 pp.

Gray, M., J. Ballou, and K. Ralls. 2003. Santa Rosa island fox
microsatellite and pedigree analysis. Unpublished report on file at Park
headquarters, Channel Islands National Park, Ventura, California. 6 pp.

Gray, M. M., and G. W. Roemer. 2001. Genetic assessment of relatedness
among individuals in the island fox (Urocyon littoralis) captive
breeding program. Unpublished report on file at Park headquarters,
Channel Islands National Park, Ventura, California. 23 pp.

Jackman, R. E., W. G. Hunt, D. E. Driscoll, and F. J. Lapsansky. 1994.
Refinements to selective trapping techniques: a radio-controlled bow net
and power snare for bald and golden eagles. Journal of Raptor Research.
28:268-273.

Kohlmann, S. G., G. A. Schmidt, R. C. Wolstenholme, and D. K. Garcelon.
2003. Island fox recovery efforts on Santa Catalina Island, California,
October 2001-October 2002, annual report. Unpublished report prepared by
the Institute for Wildlife Studies, Arcata, California, for Ecological
Restoration Department, Santa Catalina Island Conservancy, Avalon,
California. 83 pp.

National Oceanic and Atmospheric Administration, U. S. Fish and Wildlife
Service, National Park Service, California Department of Fish and Game,
California State Lands Commission, and California Department of Parks
and Recreation. 2002. Feasibility study for reestablishment of bald
eagles on the northern Channel Islands, California; environmental
assessment. Montrose Settlements Restoration Program, Long Beach,
California. 54 pp.

National Park Service. 2002. Santa Cruz Island primary restoration
program, final environmental impact statement. National Park Service,
Channel Islands National Park, Ventura, California. 249 pp.

Newman, C., G. A. Schmidt, and D. K. Garcelon. 2003. Island fox
(*Urocyon littoralis santacruzae*) distribution, abundance and survival
on Santa Cruz Island, California. Progress report: for work conducted
between 01 December 2002 through 31 January 2003. Institute for Wildlife
Studies, Arcata, California. 25 pp.

Pollock, K. H., S. R. Winterstein, and M. J. Conroy. 1989. Estimation
and analysis of survival distributions for radio-tagged animals.
Biometrics 45:99-109.

Roemer, G. W. 1999. The ecology and conservation of the island fox.
Ph.D. dissertation, University of California, Los Angeles.

Roemer, G. W., T. J. Coonan, D. Garcelon, D. K. Bascompte, and L.
Laughrin. 2001a. Feral pigs facilitate hyperpredation by golden eagles
and indirectly cause the decline of the island fox. Animal Conservation
4: 307-318.

Roemer, G. W., D. K. Garcelon, T. J. Coonan, and C. A. Schwemm. 1994.
The use of capture-recapture methods for estimating, monitoring, and
conserving island fox populations. Pages 387-400 in Halvorson, W.L, and
G.J. Maender, (eds.), The Fourth California Channel Islands Symposium:
Update on the Status of Resources. Santa Barbara Museum of Natural
History, Santa Barbara, California.

Roemer, G. W., P. S. Miller, J. Laake, C. Wilcox and T. J. Coonan.
2001b. Island fox demographic workshop report. Unpublished manuscript on
file at Park headquarters, Channel Islands National Park. 43 pp.

U. S. Fish and Wildlife Service. 2004. Endangered and threatened
wildlife and plants; listing the San Miguel Island fox, Santa Rosa
Island fox, Santa Cruz island fox, and Santa Catalina Island fox as
endangered. Federal Register 69(44): 10335-10353.

Wayne, R. K., S. B. George, D. Gilbert, P. W. Collins, S. D. Kovach, D.
Girman, and N. Lehman. 1991. A morphologic and genetic study of the
island fox, *Urocyon littoralis*. Evolution 45(8):1849-1868.

# 

# 

# 

# 

#  

# Appendix A Findings of the Island Fox Conservation Working Group

**FINDINGS OF THE**

**ISLAND FOX CONSERVATION WORKING GROUP**

**JUNE 24-26, 2003**

**VENTURA, CALIFORNIA**

![](media/image10.png){width="5.888888888888889in"
height="6.304861111111111in"}

#### 

**National Park Service**

**Channel Islands National Park**

**1901 Spinnaker Drive**

**Ventura, CA 93001**

**Work: (805) 658-5776**

**Fax: (805) 658-5798**

**Email: <tim_coonan@nps.gov>**

**SUMMARY:**

From June 24-26, 2003, the Island Fox Conservation Working Group
conducted its fifth annual meeting in Ventura, California. The working
group is a loose affiliation of agency, conservancy, zoo, non-profit and
academic representatives concerned with conservation of the island fox
(*Urocyon littoralis*). The group meets annually to exchange information
about island fox status and recovery actions, to evaluate recovery
efforts, and to identify management concerns and research needs.

Seventy people attended the meeting, representing such entities as
National Park Service, U. S. Fish and Wildlife Service California
Department of Fish and Game, ,U. S. Navy, The Nature Conservancy,
Defenders of Wildlife, Smithsonian Institution, the IUCN Canid
Specialist Group, the Institute for Wildlife Studies, the mainland zoo
community, as well the University of California and other universities
and organizations (see Appendix A).

Island fox subspecies on the northern Channel Islands are characterized
by low population sizes. Of the San Miguel Island subspecies (*U. l.
littoralis*), all but one are in captivity. The captive population has
grown from 14 individuals to 38, but reproduction continues to be lower
than in other captive populations. No Santa Rosa island foxes (*U. l.
santarosae*) exist in the wild, and the captive population now numbers
56 individuals. There are an estimated 75-100 Santa Cruz island foxes
(*U. l. santacruzae*) in the wild, and a captive population of 28
individuals.

The three subspecies on the southern Channel Islands exist at different
population sizes and are influenced by different factors. Santa Catalina
island foxes (*U. l. catalinae*) number about 220, and are recovering
from an outbreak of canine distemper virus in 1999-2000. San Clemente
island foxes (*U. l. clementae*) may number around 500, but are in
long-term decline for reasons that are not apparent. With an estimated
population size of 550-830 foxes, San Nicolas island foxes *(U. l.
dickeyi*) remain the most dense and stable of the six island fox
subspecies.

Of the six island fox subspecies, those on San Miguel, Santa Rosa, Santa
Cruz and Santa Catalina Islands were proposed for federal listing as
endangered by the U.S. Fish and Wildlife Service in December 2001. As of
June 2003 the Service had not completed a final rule regarding the
listing.

The most pressing issue for island fox conservation continues to be
golden eagle predation, which is hindering island fox recovery on the
northern Channel Islands. Although 9 golden eagles were captured and
removed in winter/spring 2003, there are currently as many as 3 eagles
on Santa Rosa, and as many as 5 on Santa Cruz. Capture efforts in late
spring failed to catch 3 of the 4 known breeding eagles on the two
islands. Annual island fox survivorship in the wild Santa Cruz Island
population, which is a barometer of the success of eagle control, was
60% in 2001 and 70% in 2002. Demographic modeling shows that at least
80% is required to avoid population decline.

Consensus of the group was that although eagle removal has apparently
increased the annual survivorship of island foxes, eagle predation has
not been adequately mitigated by live-capture efforts, and that lethal
control must be considered as an option if foxes are to be recovered.
The best use of lethal would be limited use under specific conditions;
for example, on nesting adults which had eluded live-capture efforts.

The recent discovery of breeding golden eagles on Santa Rosa Island and
the connection between those eagles and the island's non-native mule
deer is alarming. One discussion group recommended that deer carcasses
and gut piles from the deer hunt and cull be made unavailable to eagles.

Two discussion groups recommended that captive foxes in the northern
Channel Islands not be released to the wild under these conditions.
Reintroducing foxes in the face of considerable eagle presence may
require larger captive populations and a longer effort, in order to
achieve viable wild fox populations. Captive fox populations currently
exceed facility capacity on Santa Rosa and Santa Cruz Islands, and are
at capacity on San Miguel. Delaying releases would require finding
additional housing and care for foxes, either on the islands or on the
mainland. Housing additional foxes on the islands would require building
additional pens, hiring additional staff, and incurring additional food
and veterinary costs. There is a question of whether the park could
sustain an expanded program either logistically or financially.

Although housing additional foxes in mainland zoos may be an option in
the long run, it is not an option in the short-term. No institution
would be willing to take foxes this fall. Moreover, captive breeding has
been conducted on-island thus far because captive foxes returning from
the mainland could introduce pathogens to naïve island populations. The
veterinary discussion group recommended that a risk analysis be
conducted prior to moving foxes to the mainland and back again. The
island foxes currently housed at six mainland institutions are all from
San Clemente Island. If zoos are to play a larger role in island fox
captive breeding, the American Zoo and Aquarium Association's Canid
Taxon Advisory Group should be approached with such a request.

A recent assay of wild island fox blood samples discovered evidence of
previous exposure to canine distemper virus on all islands with wild
foxes. Apparently, the virus occasionally goes through wild island fox
populations and is not entirely lethal (as evident by the existence of
survivors with evidence of exposure). Because wild foxes with antibodies
against CDV have immunity, and thus protection against the next
outbreak, a greater degree of protection could be conferred to wild
populations by vaccinating wild foxes against CDV.

As evident by the distemper caused-island fox decline on Santa Catalina
Island, domestic dogs represent a real threat of disease to all island
fox populations. The veterinary group recommended that all dogs used on
park islands undergo strict vaccination and quarantine prior to arriving
on the island.

**MEETING PURPOSE:**

The purpose of the annual meeting was three-fold:

-   To exchange information and updates regarding island fox status,
    management actions, and research on all islands

-   To provide an annual technical review of current recovery efforts

-   To identify island fox management and research needs, and to foster
    cooperative efforts among the different agencies and landowners

The Island Fox Conservation Working Group is a loose affiliation of
public agency representatives, landowners, conservancies, zoological
institutions, non-profits and academics concerned about conservation
efforts for the island fox. The island fox is in decline on four and
perhaps as many as five of the six Channel Islands on which it occurs.
The species is listed as Threatened by the State of California and was
recently proposed to be Federally listed as Endangered. Because there
is, as yet, no coordinated recovery program for this species, the
working group serves as a forum for information exchange and evaluation
of current recovery efforts. The working group communicates primarily
through an annual meeting, but also via email and telephone conference
calls. The group further divides into subject matter groups to tackle
most issues. The individual working groups for this year's meeting were
veterinary issues, wild population management, captive breeding, and
reintroduction.

**BACKGROUND AND ISSUES:**

Island fox populations on the three northern islands (San Miguel, Santa
Rosa and Santa Cruz) declined catastrophically from 1995 to 1999, and
predation by golden eagles was identified as the primary cause of the
decline. A group of experts convened by the National Park Service in
1999 concluded that island foxes were threatened with extinction on San
Miguel and Santa Rosa Islands, and so identified the need to remove
golden eagles from the northern Channel Islands and to begin a captive
breeding program for island foxes on those islands. The Park began
implementing emergency recovery actions in summer 1999. Captive breeding
of island foxes began on San Miguel Island in 1999, on Santa Rosa Island
in 2000, and on Santa Cruz Island in 2002.

Golden eagle predation on island foxes on the northern Channel Islands
is facilitated by an alien prey base of feral pigs on Santa Cruz Island,
and mule deer on Santa Rosa Island. Moreover, the more diurnal nature of
the island fox, compared to other fox species, and the conversion of
native shrubland to alien annual grassland have increased the
vulnerability of island foxes to eagle predation. Breeding bald eagles,
which are highly territorial and may have deterred golden eagles from
using the islands, bred on the islands historically. Bald eagles were
missing from the northern Channel Islands since the 1950's due to the
effects of organochlorine pesticides and direct persecution by humans,
until annual releases of juveniles began in 2002 on Santa Cruz Island to
test the feasibility of reintroduction. Settlement monies from the
Montrose Chemical Company contaminant case are funding the 3-5 year
effort. Long-term solutions to the problem of golden eagle predation
also require the removal of feral pigs from Santa Cruz Island. Pig
removal is scheduled to begin in 2003/2004, as a joint project by the
National Park Service and The Nature Conservancy.

The island fox population on Santa Catalina Island in the southern
Channel Islands declined precipitously from 1999 to 2000 due to an
epidemic of canine distemper virus. The epidemic decimated island fox
populations on the eastern 80% of the island. In conjunction with the
Catalina Island Conservancy, the Institute for Wildlife Studies began a
field vaccination program for wild foxes on Catalina, has recently
relocated foxes from the west end to the east end, and has released pups
produced via captive breeding . The recent canine distemper outbreak on
Catalina underscores the vulnerability of island foxes to canine
distemper and other diseases.

Currently, there are four island fox captive breeding facilities on the
Channel Islands, and island foxes are held in captivity at six mainland
zoological institutions. Because island foxes were never bred in
captivity prior to establishment of these programs, quick development of
appropriate husbandry methods has been a priority. Much of the island
fox's reproductive physiology is still unknown, as are reasons for the
relative lack of reproductive success in the San Miguel captive breeding
program.

The influence of disease and parasites as island fox mortality factors
remains a concern for all populations. Parasites are of particular
concern on San Miguel Island.

The continued predation by golden eagles Santa Cruz island foxes remains
the primary concern for foxes on the northern Channel Islands. In the
southern islands, there are concerns about the effects of loggerhead
shrike predator management activities, feral cats, and habitat changes
on the San Clemente island fox, which appears to be in a long-term
decline for reasons that are not apparent.

The primary conservation issues discussed at the 2003 meeting were:

-   the relative success of golden eagle removal, and the need for
    lethal removal as a tool

-   whether or not to release animals to the wild on the northern
    Channel Islands, in the face of continued golden eagle presence and
    predation

-   in the absence of releases, how to house the increasing number of
    captive foxes

-   the role of mainland zoos, or any other entity, in captive breeding
    if the effort needs to be expanded beyond the current level at the
    park

-   the status of the Santa Cruz wild population and the role of captive
    breeding on the island

-   the prevalence and threat of canine diseases, and the need to
    vaccinate the wild populations against canine distemper

-   possible negative impacts of pig removal on island foxes

-   funding for island fox recovery efforts

-   vaccine and quarantine guidelines for dogs working on the islands

**STATUS OF EACH SUBSPECIES:**

San Miguel Island

Addition of 10 pups in spring 2003 increased the San Miguel captive
population to 38 foxes (23 males and 15 females). One adult female
remains in the wild, as recorded by remote automated cameras. Pup
production continues to be skewed toward males (18 of 23 pups). Seven of
the original 14 animals brought into captivity have now bred. Although
breeding success continues to be low (only 5 of 12 pairs produced a
litter in 2003), addition of pups in spring 2004 will likely increase
the San Miguel captive population to the target of 20 pairs, and allow
initial releases to the wild in fall 2004.

Santa Rosa Island

There are currently no wild foxes on Santa Rosa Island. Production of 11
pups in spring 2003 brought the captive population to 56 foxes, but was
less than pup production in spring 2002 (13 pups). Only four of 16 pairs
produced litters in 2003. Three pairs that had previously produced
litters did not produce in 2003, perhaps because a pup from the previous
year was housed in the pen with each of those pairs. Of the 44 pups born
since 2000, 27 have been female, and the overall captive sex ratio is 21
males to 35 females. An experimental release scheduled for January 2003
was canceled due to the presence of breeding golden eagles on the
island. An experimental release may occur in fall or winter 2003-2004.

Santa Cruz Island

Islandwide trapping efforts by the Institute for Wildlife Studies in
summer 2002 resulted in the capture of 97 individuals, and trapping
success suggests that the Santa Cruz Island wild fox population did not
decline between 2001 and 2002. Seven radiocollared foxes died during
2002, and eagle predation was cause of death for 5 of the 7. Those 5
eagle-caused mortalities included 2 of 3 captive-born juveniles released
in December 2002. The previous year, eagle predation accounted for 8 of
9 mortalities of radiocollared foxes on Santa Cruz Island. Annual
survivorship of island foxes, as estimated from radiotelemetry, was 61%
in 2001 and 70% in 2002. Annual survivorship of 80% is required for an
increasing population.

Five of the 10 captive fox pairs on Santa Cruz Island produced litters
in spring 2003. The 10 pups increased the captive population to 30
animals. Pups produced in spring 2003 will likely be released to the
wild in fall 2003.

San Nicolas Island

Grace Smith of the U.S. Navy and Greg Schmidt of the Institute for
Wildlife Studies reported that the island fox population on San Nicolas
continues to be dense and stable. Two grids trapped in summer 2002 had
adult densities of over 20 foxes per square kilometer, which are the
highest densities reported yet for the species. The islandwide estimate,
based on mark-recapture estimates from grid trapping, is 550-830 foxes.

Santa Catalina Island

Dr. Winston Vickers of the Institute for Wildlife Studies reported that
8 of the 11 Santa Catalina Island captive females produced litters in
spring 2003. Twenty-four -hour post-whelping monitoring revealed several
cases of inattentive females, and triggered aggressive neonatal care by
staff. Pups were pulled from inattentive females, hand-raised for 1-2
days, and fostered successfully into other captive litters. The island's
captive breeding facility produced 16 pups in 2003. Greg Schmidt and
Steve Kohlmann of the Institute reported on the success of island fox
translocations and release of captive foxes. Survivorship has been high
for the two translocations conducted thus far, and for the two releases
of captive-born animals. The islandwide population is estimated to be
220 foxes, and the probability of extinction, as estimated via
population viability analysis, is less than 1%. The apparent success of
translocations and captive breeding suggest that such actions may be
necessary for only a few more years.

San Clemente Island

Greg Schmidt of the Institute for Wildlife Studies reported results from
annual monitoring of island foxes on San Clemente Island, a study that
began in 1988. Island foxes are generally declining on San Clemente
Island, for unknown reasons. The role of predator management activities,
instituted for recovery of endangered San Clemente Island shrikes, in
the apparent decline is still unclear. Of the three long-term grids
monitored, there has been moderate fox control on two. Generally, there
are higher fox numbers where predator control has been minimal, and
where feral cat abundance is lower.

**GOLDEN EAGLE REMOVAL:**

Since fall 1999, staff from the Santa Cruz Predatory Bird Research Group
have live-captured and removed 31 golden eagles from the northern
Channel Islands. Captured birds include 26 adult, sub-adult or juvenile
eagles captured via bow-net and released in northeastern California, and
5 eaglets captured by hand from island nests and fostered into mainland
golden eagle nests or hacked on the mainland. Satellite radiotelemetry
affixed to the first 12 captured birds showed that none returned to the
Channel Islands for the 1.5-year life of the tag. Cost of total eagle
trapping efforts after four years was approximately \$527,000.

Captures in 2003 include 6 eagles captured on Santa Cruz Island in
February and March 2003 at a site where carrion was being provided for
juvenile bald eagles released on the island in summer 2002. Golden
eagles were likely attracted to the carrion site by the presence of bald
eagles.

Although golden eagle breeding had been documented on Santa Cruz Island
since 1999, golden eagles were never known to breed on Santa Rosa Island
until this year. Two breeding pairs of golden eagles were discovered on
the island in January and February 2003. One pair abandoned their nest
attempt in March, and the other pair produced one chick, which was
removed by hand from the nest in June. The adult male from the latter
pair was live-captured in May 2003.

Because several alternate nests were observed in the Santa Rosa golden
eagle territories, eagles have likely been breeding on Santa Rosa for
several years, and Santa Rosa eagle nests may be the source of many
eagles observed on neighboring Santa Cruz Island. A cursory examination
of prey items in the nests found remains of deer fawns, skunks, foxes,
and many birds (ravens, mallards, barn owls, California quail, western
meadowlarks). The presence of numerous fox remains indicates that golden
eagles had colonized the island by 1998 or 1999, when foxes were still
extant on the island. The presence of deer fawn remains underscores the
importance of mule deer to golden eagles on Santa Rosa Island. Carcasses
from the cull in November and December allow golden eagles to accrue the
energetic resources necessary to attempt breeding, and fawn availability
in the spring allows nesting eagles to successfully fledge young.

By the end of trapping efforts in summer 2003, there were estimated to
be 8 golden eagles left on the northern Channel Islands. This included 3
adults on Santa Rosa, 3 adults on Santa Cruz, and 2 subadults on Santa
Cruz.

**PATHOLOGY, DISEASE AND PARASITES, AND REPRODUCTION:**

Dr. Linda Munson of UC Davis reported on her continuing study of island
fox pathology. After five years, 290 island fox carcasses have been
necropsied. A database of lesions and parasites has been compiled, with
the goal of distinguishing debilitating and fatal diseases from
incidental causes of mortality or morbidity.

Factors that are of concern include the following:

-   Emaciation has been observed in some southern Channel Island foxes,
    in the presence of apparent food and good dentition, for unknown
    reasons.

-   Amyloidosis, the presence of abnormal protein deposits, has been
    observed in emaciated foxes.

-   Systemic mineralization has been observed in foxes from San Clemente
    Island.

-   Ear mites have produced lesions and chronic inflammation of the ear
    canal in many Santa Catalina Island foxes, and in several cases were
    associated with aggressive ceruminous gland carcinomas which caused
    mortality.

-   Colonic lesions due to spirocercid parasites were observed in foxes
    from San Miguel, Santa Rosa, Santa Cruz, and San Nicolas islands.
    Such lesions could cause perforation of the gut.

-   Some neonatal deaths also occurred in captive foxes.

-   Canine distemper virus (CDV) was the cause of the recent island fox
    decline on Santa Catalina Island, and remains a primary concern for
    all island fox populations. A 2001-2002 serosurvey (see below)
    showed that wild foxes on Santa Catalina, San Nicolas, San Clemente
    and Santa Cruz islands had evidence of exposure to CDV. This
    indicates that CDV is not fully lethal, but is occasionally
    epizootic in island fox populations. Since previous exposure confers
    immunity against CDV, the proportion of the sample that is
    seropositive is a measure of the level of protection afforded to the
    population. Less than 50% seroprevalence on Santa Clemente Island
    indicates that population is not adequately protected against an
    epizootic of CDV, and vaccinating wild foxes could increase the
    proportion of wild foxes that would survive the next epidemic.
    Vaccination may also be appropriate for Santa Cruz Island foxes,
    though they show 77% seroprevalence; the critical status of that
    population may be sufficient reason to increase protection through
    vaccination.

Dr. Deanna Fritcher of UC Davis reported on her 2001-2002 serosurvey of
wild foxes on San Clemente, Santa Catalina, San Nicolas, and Santa Cruz
Islands (there are no wild foxes on Santa Rosa, and only one on San
Miguel). In addition to the CDV results mentioned above, incidence of
canine parvovirus (CPV) increased 90-100% since 1988; there were
particularly high titers on San Clemente Island. Dr. Fritcher also
reported on her study of island fox pregnancy rates, neonatal mortality,
and perinatal mortality on Santa Catalina Island. Pregnancy rates were
higher in wild foxes than in captive foxes, but perinatal mortality was
less in captivity.

Dr. Sharon Patton of the University of Tennessee reported on preliminary
results from the risk assessment for treating parasites in captive
island foxes, a project directed by Dr. Rex Sohn of the USGS-Biological
Resources Division's National Wildlife Health Center. Fecal parasite
surveys were conducted for captive foxes on San Miguel, Santa Rosa and
Santa Cruz Islands. Overall, parasites were most prevalent in San Miguel
foxes. All San Miguel samples were positive for the hookworm *Uncinaria
stenocephala*, compared to 10-30% of the samples from the other two
islands. Compared to other hookworms, *U. stenocephala* has much less
impact on individual health. Spirocercids were found in 70-90% of the
samples from all three islands. Adult spirocercids were found in nodules
in the colon of some necropsied foxes, which is a unique location;
spirocercids in mainland hosts are found in the esophagus. The lungworm
*Angiocaulus gubernaculatus* was found only in San Miguel foxes, where
it was present in 35% of the pens. The panel convened for the risk
assessment has determined that currently there is little clinical
justification for the use of anthelmintics in island foxes, and the
primary concerns for such use would be the effect on non-target
sprirocercids and *Angiocaulus*. The panel compiled a list of preferred
anthelmintics, recommended dosages, and contraindications, should
treatment for internal parasites be required.

Dr. Cheri Asa of the St. Louis Zoo reported on the success of a relaxin
blood test for pregnancy (the occurrence of pseudopregnancy in island
foxes prevents determination of pregnancy via monitoring progesterone
and estradiol). Dr. Asa also summarized her island fox reproductive
studies to date. Unlike every other canid studied thus far, female
island foxes do not ovulate every breeding season. Most female island
foxes paired with males ovulate, but those housed with other females or
by themselves do not. This appears to be a case of induced ovulation,
but induced estrus cannot be ruled out.

**GENETICS:**

Melissa Gray of UCLA reported on the use of genetic information to
develop a release strategy for Santa Rosa Island captive foxes. A
pedigree developed from relatedness values was used to identify
over-represented individuals, and their descendants, for release. All
founders on Santa Rosa are highly related. Her recent analysis of the
Santa Cruz Island captive and wild populations showed that the mean
number of alleles was higher than in the San Miguel or Santa Rosa
populations, that average inbreeding was low, and that the captive
population had captured an adequate sample of the population's genetic
diversity.

Andres Aguilar, also of UCLA, reported on fitness--related genetic
variation in island foxes. Genotyping heretofore had been done on
so-called neutral markers, which have no known relation to fitness.
Analysis of genes that code for the major histocompatibility complex
(MHC) in island foxes revealed heterozygosity in San Nicolas Island
foxes, which had previously showed no variation at other loci.

**MAINLAND ZOO POPULATION:**

Assistant Curator Ingrid Russell of the Santa Barbara Zoo reported a
total of 16 island foxes held in the following mainland zoos: Santa
Barbara Zoo, California Living Desert Museum, Charles Paddock Zoo,
Utah's Hogle Zoo, the Orange County Zoo, and the Los Angeles Zoo. Thus
far there has been a male bias in pups born in mainland zoos.

**LEGAL STATUS:**

In December 2001 the U.S. Fish and Wildlife Service proposed to list
four island fox subspecies (San Miguel, Santa Rosa, Santa Cruz, and
Santa Catalina) as Endangered under the Federal Endangered Species Act.
The Service had one year from date of publication of the proposed rule
to make a final decision on listing. By June 2003 the Service had not
published a final rule.

**FINDINGS:**

Veterinary Issues

1.  Veterinary care for captive island foxes: Fox care technicians
    should follow appropriate veterinary guidelines. The appropriate
    veterinarian should be contacted if an animal appears sick or
    injured. All fox care staff should be properly trained, and such
    training should be coordinated between the NPS and IWS. Such
    training should include first aid training for injuries, taking and
    handling of blood samples, neonatal care, treatment for shock,
    "trigger points" for hospitalization or treatment. Project
    veterinarians should impart this information via annual short
    courses.

2.  Guidelines for use of dogs: Strict guidelines should be implemented
    for vaccination and quarantine for dogs on islands, including pet
    dogs on Santa Catalina Island, pig hunting dogs on Santa Cruz
    Island, and ranch dogs on Santa Rosa Island. We recommend
    implementation of the park's draft guidelines, as amended, for use
    of dogs in the park.

3.  Canine distemper virus vaccination: Recent serological surveys show
    that wild foxes have antibodies against canine distemper virus
    (CDV). This indicates that CDV is occasionally epizootic in island
    fox populations. Those that have antibodies have immunity, but low
    seroprevalence on San Clemente Island indicates that populations is
    not adequately protected. Vaccinating a portion of the wild
    population on that island, and on Santa Cruz Island, could confer an
    immunologic advantage to those foxes in the face of an epidemic.

4.  Rabies: There is currently not a sufficient risk of rabies on the
    islands to warrant vaccination of foxes for rabies, but we do
    recommend rabies vaccinations for all staff handling island foxes.

5.  Diagnosis of pregnancy and evaluation of sperm quality: Knowledge of
    fertility and pregnancy would optimize management of captive foxes,
    and could determine cause of reproductive failure. Because handling
    constitutes a stress that may impair reproductive function, we
    recommend that pregnancy tests (utrasound and/or relaxin assays) and
    semen evaluation only be conducted on captive foxes that have thus
    far failed to produce pups. Those procedures should be implemented
    under the guidelines developed.

6.  Potential inter-island or mainland-island movement of foxes: The
    unique parasites/pathogens on some islands and the insular evolution
    of foxes without mainland diseases make the risk of acquiring or
    transmitting disease substantial for such movements. We recommend
    that such movement be discouraged, that a specific risk analysis be
    conducted prior to any move, and that strict quarantine procedures
    be observed for such movements.

7.  Veterinary handbook: We will develop a veterinary handbook for use
    in the island fox captive breeding programs, and in zoos. The
    handbook should be completed by spring 2004.

Management of Wild Island Fox Populations

1.  Golden eagle monitoring: Because golden eagle predation is still the
    primary mortality factor for island foxes on the northern Channel
    Islands, and because such predation will hinder recovery, monitoring
    efforts for golden eagles should be increased. Analysis of golden
    eagle feathers/blood could determine the source of eagles (mainland
    or island). The newly discovered nests on Santa Rosa Island should
    be excavated to investigate the prey base supporting golden eagle
    nesting on that island.

2.  Lethal removal of golden eagles: Removal of golden eagles should be
    the highest priority management action, with a goal of no resident
    eagles, and lethal removal of golden eagles needs to be a management
    option. Eagle removal, and fox recovery, will likely fail without
    it. The tool might best be used in a selective fashion, for breeding
    females that have eluded capture by other methods. The approach
    needs to be adaptive in nature. The administrative process for
    obtaining a permit should be assessed, and the feasibility of lethal
    removal investigated. Above all, the process should be expedited.

3.  Management of eagle prey base: Golden eagles on Santa Rosa Island
    are supported by non-native mule deer, and that food source needs to
    be reduced or eliminated. Gut piles from the annual hunt and
    carcasses from the annual cull should be removed from the field or
    otherwise made unavailable to eagles. Deer carcasses should be made
    available for golden eagle capture efforts.

The effect of pig removal on golden eagle prey selection and use of the
islands in unknown. If predation on foxes increases as a result of pig
carcass availability, or conversely, absence of pigs and prey-switching
to island foxes, then a contingency plan should be in place to pull more
foxes into captivity. Pig carcasses should ideally be made unavailable
to eagles. The sample of collared foxes should be increased to allow
greater resolution in estimating survivorship and mortality sources for
foxes.

4.  San Clemente fox decline: Research should be conducted to
    investigate cause(s) of the apparent island fox decline on San
    Clemente Island. Specifically, has the expansion of alien annual
    grasslands decreased the amount of high-quality habitat available
    for foxes? Is social disruption occurring? Do foxes compete with
    feral cats?

Management of Captive Fox Populations

1.  Expansion of captive breeding facilities on islands: Although Santa
    Rosa facilities are currently at capacity, we reinforce last year\'s
    recommendation that fox releases should not occur while eagles
    remain. Furthermore, it would reduce the Santa Rosa population's
    chances of survival if growth of the captive population ceased or
    slowed due to lack of space. We recommend the construction of 10
    additional pens on Santa Rosa as soon as possible and the
    acquisition of additional staff to care for the captive foxes.

Santa Cruz facilities are also at capacity. Should pig removal on Santa
Cruz result in increased fox predation by golden eagles, additional
caging will be required to facilitate captive breeding to off-set
increased predation rates post-release and may be required as sanctuary
housing for additional Santa Cruz foxes. The Santa Cruz population is
known to be among the most genetically variable fox population and the
loss of additional genetic variation in this population should be
avoided.

> Captive breeding programs generally aspire to maximize gene diversity
> in founding populations. Population modeling should be conducted to
> examine the impacts of different strategies of breeding and sanctuary
> on the retention of genetic diversity in the presence and absence of
> releases and in the presence and absence of facility expansion.
> Sanctuary could be provided by capturing fox pups instead of adults.
> This would minimize negative demographic effects on the wild
> population. Additionally, the existing wild population on Santa Cruz
> should be evaluated for a minimal acceptable population size,
> representing the population size at which the remaining Santa Cruz
> specimens will be captured for sanctuary housing in the event of
> further population decline. Genetic and demographic criteria should be
> used to prioritize individuals for sanctuary housing. Based on the
> results of this modeling exercise, we recommend construction of
> additional enclosures and additional staff on Santa Cruz as necessary.
>
> San Miguel facilities are projected to be at capacity after the next
> breeding season. Thus, construction of additional facilities there
> will likely be necessary soon.

2.  Potential for moving foxes to mainland facilities: If it is not
    possible to expand breeding facilities on the islands, the movement
    of some island foxes to the mainland will be necessary.
    Investigations into the potential for housing island foxes on the
    mainland should begin immediately, as development/recruitment of
    mainland facilities will take time.

3.  Fire evacuation plans: We recommend the development of a fire
    evacuation plan to facilitate removal of a genetically
    representative and demographically robust sample of foxes from each
    island breeding facility in the event of fire emergency. Creation of
    this plan can be facilitated utilizing studbook data and should be
    updated annually. Genetic prioritization should be accompanied by
    staff safety protocols and "Rules of Engagement".

4.  Maintenance of subspecies: We repeat the recommendation from last
    year that a thorough risk analysis should be undertaken on the
    likely costs and benefits of allowing some genetic mixture between
    subspecies, especially the Santa Rosa and San Miguel populations.
    Assessment of the probable demographic and genetic effects on the
    populations should be combined with assessment of the probable
    disease risks. If the risk assessment is favorable, an action plan
    should be developed.

5.  Behavioral observations of captive foxes: We recommend the formation
    of a committee to investigate and coordinate behavioral observations
    at captive breeding facilities and develop research questions. We
    recommend that existing ethograms (behavioral data recording sheets)
    be combined and evaluated. Collection of behavioral data should be
    standardized across zoological institutions and island breeding
    facilities to enable and enhance comparative data analysis.

6.  Mate-choice experiments: We recommend that mate-choice experiments
    be conducted where possible. Foxes that have not bred successfully
    with their assigned mate may be more likely to breed with a mate of
    their own choice. San Miguel and Santa Rosa captive facilities lend
    themselves to such experiments due to biased sex ratios.

7.  Mainland zoo population: The zoo population, which consists of foxes
    from San Clemente Island, currently has no clear short-term or
    long-term management goals. It is critical that goals be established
    to ensure responsible management of this population. In addition,
    clear management goals will encourage further and expanded
    participation in the Island Fox Population Management Plan by
    zoological institutions. The mainland zoo community is waiting for
    input from the Island Fox Conservation Team to guide zoo fox
    management goals. Potential management goals are a) to develop a
    long-term genetically viable population of San Clemente foxes; b) to
    continue to house San Clemente foxes in small numbers for education
    programs; c) to phase-out San Clemente foxes, thus creating space
    for other sub-species for a breeding program; and d) to house
    surplus non-breeders from island breeding facilities. The Canid TAG
    should be contacted prior to the AZA Annual Meeting in September
    2003 to discuss goals for this population.

8.  Interactions of wild and captive foxes: We recommend continuation of
    current measures to avoid problem interactions between captive and
    wild foxes. Shock collars appear to be the most viable option as
    barriers are likely to be ineffective and removal of wild foxes
    causing problems will likely result in movement of additional foxes
    into the territory.

9.  Mainland research facility: We do not recommend immediate creation
    of a mainland research facility. While existing foxes on the
    mainland may be utilized for research, research alone is not
    sufficient reason for island/mainland movements. The resources
    needed to create such a facility might be better spent in facility
    expansions at existing island sites. None of the currently
    participating zoos have the resources to support such a facility at
    this time or to breed foxes at a rate to stock such a facility. In
    the absence of the ability to move specimens between mainland and
    islands, it is unlikely that specimens from islands could or should
    be used to stock such a facility. However, if the decision is made
    to move foxes from the islands to the mainland, it would be highly
    desirable to find a facility that could house sufficient numbers of
    foxes to support a research program.

Reintroduction of Island Foxes

1.  Reintroduction planning: We recommend that different island groups
    do collaborative modeling and planning of release programs,
    including logistical and political constraints, to improve recovery
    potential and to enhance the scientific basis of recovery.
    Specifically, we recommend the development of standard protocols
    when possible to aid the development of comparable data sets, which
    should permit rigorous evaluation of methodologies.

2.  Conditions for release: Given the continuing presence of golden
    eagles, we recommend for this year that foxes not be released on the
    islands. We recommend building temporary holding facilities and
    developing alternative options for assistance by non-NPS staff in
    the care of captive- held foxes. We also recommend looking at
    alternative options for long-term care of captive-held foxes,
    including mainland facilities.

3.  Choice of foxes for release: In the absence of golden eagles, we
    recommend that non-reproducing genetically surplus foxes be
    considered for release to study behavioral ecology post-release and
    to maintain ecosystem function.

4.  Post-release monitoring: Foxes should not be released without a
    monitoring plan in place which clearly explains how the release will
    promote recovery or improve knowledge of fox biology. At a minimum,
    foxes would be monitored to detect mortalities rapidly, which would
    allow more accurate identification of causes of mortality. More
    intensive monitoring is preferable and would result in information
    regarding basic biology and ecology of the foxes, including
    movements, habitat use, foraging, interactions, home range etc. We
    recommend that initial monitoring include systematic trapping of
    released foxes in order to assess the status of individual foxes,
    along with intensive telemetry monitoring. A review of the
    monitoring program should allow us to determine the most effective
    way to identify foxes that might need recovery for future releases.

**APPENDIX A**

###### LIST OF MEETING PARTICIPANTS

+-----------------------------------+-----------------------------------+
| Angela Aarhus                     | Andres Aguilar                    |
|                                   |                                   |
| Catalina Island Conservancy       | UCLA                              |
+-----------------------------------+-----------------------------------+
| Cheryl Asa                        | Erik Aschehoug                    |
|                                   |                                   |
| St. Louis Zoo                     | The Nature Conservancy            |
+-----------------------------------+-----------------------------------+
| Vickie Bakker                     | Karen Blumenshine                 |
|                                   |                                   |
| UC Davis                          | Santa Barbara Zoo                 |
+-----------------------------------+-----------------------------------+
| Dan Blumstein                     | Kevin Breen                       |
|                                   |                                   |
| UCLA                              | Orange County Zoo                 |
+-----------------------------------+-----------------------------------+
| Kelly Brock                       | Pedro Chavarria                   |
|                                   |                                   |
| U.S. Navy, SW                     | National Park Service             |
+-----------------------------------+-----------------------------------+
| Matt Christianson                 | Geoff Cline                       |
|                                   |                                   |
| Institute for Wildlife Studies    | Institute for Wildlife Studies    |
+-----------------------------------+-----------------------------------+
| Paul Collins                      | Tim Coonan                        |
|                                   |                                   |
| Santa Barbara Museum of Natural   | National Park Service             |
| History                           |                                   |
+-----------------------------------+-----------------------------------+
| Susan Coppelli                    | Keri Dearborn                     |
|                                   |                                   |
| National Park Service             | Los Angeles Zoo                   |
+-----------------------------------+-----------------------------------+
| Bob DeLong                        | Forrest deSpain                   |
|                                   |                                   |
| NMFS National Marine Mammal Lab   | Orange County Zoo                 |
+-----------------------------------+-----------------------------------+
| Katie Drexhage                    | Jana Edwards                      |
|                                   |                                   |
| USFWS -- Ventura Field Office     |                                   |
+-----------------------------------+-----------------------------------+
| Bridget Fahey                     | Erin Fleming                      |
|                                   |                                   |
| USFWS -- Ventura Field Office     | Los Angeles Zoo                   |
+-----------------------------------+-----------------------------------+
| Deanna Fritcher                   | David Garcelon                    |
|                                   |                                   |
| UC Davis Wildlife Health Center   | Institute for Wildlife Studies    |
+-----------------------------------+-----------------------------------+
| Keith Gilchrist                   | Dave Graber                       |
|                                   |                                   |
| Charles Paddock Zoo               | National Park Service             |
+-----------------------------------+-----------------------------------+
| Melissa Gray                      | Lynn Hall                         |
|                                   |                                   |
| UCLA                              | Fennec Breeder                    |
+-----------------------------------+-----------------------------------+
| Karl Hill                         | Dale Kernahan                     |
|                                   |                                   |
| Santa Barbara Zoo                 | Santa Barbara Zoo                 |
+-----------------------------------+-----------------------------------+
| Devra Kleiman                     | Steve Kohlmann                    |
|                                   |                                   |
| Smithsonian Institute             | Institute for Wildlife Studies    |
+-----------------------------------+-----------------------------------+
| Brian Latta                       | Lyndal Laughrin                   |
|                                   |                                   |
| Santa Cruz Predatory Bird         | UC Santa Cruz Island Preserve     |
| Research Group                    |                                   |
+-----------------------------------+-----------------------------------+
| David Lawhead                     | Andrea Lehotsky                   |
|                                   |                                   |
| CDFG                              | National Park Service             |
+-----------------------------------+-----------------------------------+
| Colleen Lynch                     | Catrina Martin                    |
|                                   |                                   |
| American Zoo and Aquarium         | U.S. Fish and Wildlife Service    |
| Association                       |                                   |
+-----------------------------------+-----------------------------------+
| Jonna Mazet                       | Kate McCurdy                      |
|                                   |                                   |
| UC Davis Wildlife Health Center   | National Park Service             |
+-----------------------------------+-----------------------------------+
| Mary Ann Meyers                   | Pat Meyer                         |
|                                   |                                   |
|                                   | Los Angeles Zoo                   |
+-----------------------------------+-----------------------------------+
| Samantha Moorehead                | Linda Munson                      |
|                                   |                                   |
| Santa Barbara Zoo                 | UC Davis                          |
+-----------------------------------+-----------------------------------+
| Christopher Newman                | Julia Parker                      |
|                                   |                                   |
| Institute for Wildlife Studies    | Santa Barbara Zoo                 |
+-----------------------------------+-----------------------------------+
| Sharon Patton                     | Stephanie Provinsky               |
|                                   |                                   |
| Univ. of Tennessee, Knoxville     | National Park Service             |
+-----------------------------------+-----------------------------------+
| Katherine Ralls                   | Gary Roemer                       |
|                                   |                                   |
| Smithsonian Institution           | New Mexico State University       |
+-----------------------------------+-----------------------------------+
| Ingrid Russell                    | Keith Rutz                        |
|                                   |                                   |
| Santa Barbara Zoo                 | National Park Service             |
+-----------------------------------+-----------------------------------+
| Greg Schmidt                      | Sheri Schroeder                   |
|                                   |                                   |
| Institute for Wildlife Studies    |                                   |
+-----------------------------------+-----------------------------------+
| Peter Schuyler                    | Cathy Schwemm                     |
|                                   |                                   |
| Catalina Island Conservancy       | National Park Service             |
+-----------------------------------+-----------------------------------+
| Brian Smith                       | Grace Smith                       |
|                                   |                                   |
| UCLA                              | U.S. Navy, San Nicolas Island     |
+-----------------------------------+-----------------------------------+
| Rex Sohn                          | Marsha Sovada                     |
|                                   |                                   |
| USGS-BRD Nat. Wildlife Health     | USGS-BRD North. Prairie Wildl.    |
| Center                            | Res. Center                       |
+-----------------------------------+-----------------------------------+
| Wendy Stanford                    | Nancy Thomas                      |
|                                   |                                   |
| Santa Barbara Zoo                 | USGS-BRD Nat. Wildlife Health     |
|                                   | Center                            |
+-----------------------------------+-----------------------------------+
| Anna Toline                       | Winston Vickers                   |
|                                   |                                   |
| USFWS -- Ventura Field Office     | Institute for Wildlife Management |
+-----------------------------------+-----------------------------------+
| Sandy Vissman                     | Bob Wayne                         |
|                                   |                                   |
| USFWS -- Carlsbad Field Office    | UCLA                              |
+-----------------------------------+-----------------------------------+
| Cynthia Wilkerson                 | Mark Willett                      |
|                                   |                                   |
| Defenders of Wildlife             | NPS contract vet                  |
+-----------------------------------+-----------------------------------+
| Ian Williams                      | Rosie Woodroffe                   |
|                                   |                                   |
| National Park Service             | UC Davis                          |
+-----------------------------------+-----------------------------------+

# Appendix B Breeding Charts and Lists of Foxes in Captivity

[]{#__RefHeading___Toc73507714 .anchor}Figure 8. Breeding and pedigree
chart for captive San Miguel Island foxes.

[]{#__RefHeading___Toc69872238 .anchor}Table 13. Island foxes in captive
breeding facility on San Miguel Island.

<table>
<colgroup>
<col style="width: 7%" />
<col style="width: 7%" />
<col style="width: 5%" />
<col style="width: 7%" />
<col style="width: 11%" />
<col style="width: 8%" />
<col style="width: 9%" />
<col style="width: 21%" />
<col style="width: 18%" />
<col style="width: 1%" />
</colgroup>
<thead>
<tr class="header">
<th><strong>Pen<sup>1</sup></strong></th>
<th><strong>ID</strong></th>
<th><strong>Sex</strong></th>
<th><strong>Age<sup>2</sup></strong></th>
<th><strong>Born</strong></th>
<th><strong>Sire</strong></th>
<th><strong>Dam</strong></th>
<th><strong>Capture Date</strong></th>
<th><strong>Capture Area</strong></th>
<th></th>
</tr>
</thead>
<tbody>
<tr class="odd">
<td>M01</td>
<td>85764</td>
<td>F</td>
<td>2</td>
<td>Captive</td>
<td>44829</td>
<td>90D1A</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td>87F53</td>
<td>M</td>
<td>2</td>
<td>Captive</td>
<td>7574A</td>
<td>92C32</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="odd">
<td>M02</td>
<td>B0E36</td>
<td>M</td>
<td>2</td>
<td>Captive</td>
<td>7574A</td>
<td>92C32</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td>M03</td>
<td>7574A</td>
<td>M</td>
<td>6</td>
<td>Wild</td>
<td></td>
<td></td>
<td>5/14/1999</td>
<td>Willow Canyon</td>
<td></td>
</tr>
<tr class="odd">
<td></td>
<td>92C32</td>
<td>F</td>
<td>6</td>
<td>Wild</td>
<td></td>
<td></td>
<td>5/17/1999</td>
<td>Willow Canyon</td>
<td></td>
</tr>
<tr class="even">
<td>M04</td>
<td>84E33</td>
<td>M</td>
<td>1</td>
<td>Captive</td>
<td>44829</td>
<td>90D1A</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="odd">
<td>M07</td>
<td>90D1A</td>
<td>F</td>
<td>6</td>
<td>Wild</td>
<td></td>
<td></td>
<td>9/2/1999</td>
<td>Willow Canyon</td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td>44829</td>
<td>M</td>
<td>6</td>
<td>Wild</td>
<td></td>
<td></td>
<td>9/4/1999</td>
<td>Willow Canyon</td>
<td></td>
</tr>
<tr class="odd">
<td>M08</td>
<td>53A78</td>
<td>F</td>
<td>1</td>
<td>Captive</td>
<td>47B06</td>
<td>E2677</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td>C111F</td>
<td>M</td>
<td>1</td>
<td>Captive</td>
<td>7574A</td>
<td>92C32</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="odd">
<td>M09</td>
<td>7534A</td>
<td>F</td>
<td>11</td>
<td>Wild</td>
<td></td>
<td></td>
<td>9/4/1999</td>
<td>Nidever Canyon</td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td>70C1D</td>
<td>M</td>
<td>3</td>
<td>Captive</td>
<td>44829</td>
<td>90D1A</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="odd">
<td>M10</td>
<td>C311C</td>
<td>M</td>
<td>1</td>
<td>Captive</td>
<td>11F73</td>
<td>F6558</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td>52F0C</td>
<td>M</td>
<td>1</td>
<td>Captive</td>
<td>11F73</td>
<td>F6558</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="odd">
<td>M11</td>
<td>47B06</td>
<td>M</td>
<td>4</td>
<td>Captive</td>
<td>44829</td>
<td>90D1A</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td>E2677</td>
<td>F</td>
<td>6</td>
<td>Wild</td>
<td></td>
<td></td>
<td>9/11/1999</td>
<td>Willow Canyon</td>
<td></td>
</tr>
<tr class="odd">
<td>M12</td>
<td>91167</td>
<td>M</td>
<td>1</td>
<td>Captive</td>
<td>7574A</td>
<td>92C32</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td>B0B25</td>
<td>F</td>
<td>5</td>
<td>Wild</td>
<td></td>
<td></td>
<td>9/28/1999</td>
<td>Nidever Canyon</td>
<td></td>
</tr>
<tr class="odd">
<td>M13</td>
<td>11F73</td>
<td>M</td>
<td>3</td>
<td>Captive</td>
<td>44829</td>
<td>90D1A</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td>F6558</td>
<td>F</td>
<td>5</td>
<td>Wild</td>
<td></td>
<td></td>
<td>10/4/1999</td>
<td>Green Mountain</td>
<td></td>
</tr>
<tr class="odd">
<td>M14</td>
<td>57150</td>
<td>M</td>
<td>6</td>
<td>Wild</td>
<td></td>
<td></td>
<td>10/4/1999</td>
<td>Green Mountain</td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td>60921</td>
<td>F</td>
<td>6</td>
<td>Wild</td>
<td></td>
<td></td>
<td>9/24/1999</td>
<td>Green Mountain</td>
<td></td>
</tr>
<tr class="odd">
<td>M15</td>
<td>B7E0A</td>
<td>F</td>
<td>2</td>
<td>Captive</td>
<td>47B06</td>
<td>E2677</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td>E666D</td>
<td>M</td>
<td>1</td>
<td>Captive</td>
<td>C4A16</td>
<td>71071</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="odd">
<td>M16</td>
<td>90C7D</td>
<td>F</td>
<td>1</td>
<td>Captive</td>
<td>C4A16</td>
<td>71071</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td>83C24</td>
<td>M</td>
<td>3</td>
<td>Captive</td>
<td>44829</td>
<td>90D1A</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="odd">
<td>M17</td>
<td>C7303</td>
<td>M</td>
<td>3</td>
<td>Captive</td>
<td>7574A</td>
<td>92C32</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td>11929</td>
<td>F</td>
<td>4</td>
<td>Captive</td>
<td>44829</td>
<td>90D1A</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="odd">
<td>M18</td>
<td>C4A16</td>
<td>M</td>
<td>3</td>
<td>Captive</td>
<td>7574A</td>
<td>92C32</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td>71071</td>
<td>F</td>
<td>5</td>
<td>Wild</td>
<td></td>
<td></td>
<td>8/23/1999</td>
<td>Cardwell</td>
<td></td>
</tr>
<tr class="odd">
<td>M19</td>
<td>92804</td>
<td>F</td>
<td>12</td>
<td>Wild</td>
<td></td>
<td></td>
<td>10/24/1999</td>
<td>Willow Canyon</td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td>85D02</td>
<td>M</td>
<td>5</td>
<td>Wild</td>
<td></td>
<td></td>
<td>9/17/1999</td>
<td>Cardwell</td>
<td></td>
</tr>
<tr class="odd">
<td>M20</td>
<td>B4E60</td>
<td>M</td>
<td>2</td>
<td>Captive</td>
<td>44829</td>
<td>90D1A</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td>E270B</td>
<td>M</td>
<td>2</td>
<td>Captive</td>
<td>44829</td>
<td>90D1A</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="odd">
<td>M21</td>
<td>66C6E</td>
<td>M</td>
<td>2</td>
<td>Captive</td>
<td>47B06</td>
<td>E2677</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td>13212</td>
<td>M</td>
<td>2</td>
<td>Captive</td>
<td>47B06</td>
<td>E2677</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="odd">
<td>M22</td>
<td>03A13</td>
<td>F</td>
<td>1</td>
<td>Captive</td>
<td>47B06</td>
<td>E2677</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td>5797C</td>
<td>M</td>
<td>1</td>
<td>Captive</td>
<td>7574A</td>
<td>92C32</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="odd">
<td colspan="10"><p><sup>1</sup>Pens M01-M11 are at Willow Canyon site;
pens M12-M21 are at Brooks Canyon site.</p>
<p><sup>2</sup>in years, as of fall 2003</p></td>
</tr>
</tbody>
</table>

[]{#__RefHeading___Toc69872239
.anchor}![](media/image11.wmf){width="6.2875in"
height="4.700694444444444in"}

Table 14. Island foxes in captive breeding facility on Santa Rosa
Island.

<table>
<colgroup>
<col style="width: 7%" />
<col style="width: 7%" />
<col style="width: 5%" />
<col style="width: 7%" />
<col style="width: 16%" />
<col style="width: 10%" />
<col style="width: 9%" />
<col style="width: 16%" />
<col style="width: 18%" />
<col style="width: 0%" />
</colgroup>
<thead>
<tr class="header">
<th><strong>Pen</strong></th>
<th><strong>PitTag</strong></th>
<th><strong>Sex</strong></th>
<th><strong>Age</strong></th>
<th><strong>Born</strong></th>
<th><strong>Sire</strong></th>
<th><strong>Dam</strong></th>
<th><strong>Date Captured</strong></th>
<th colspan="2"><strong>Capture Area</strong></th>
</tr>
</thead>
<tbody>
<tr class="odd">
<td>R01</td>
<td>2571A</td>
<td>F</td>
<td>2</td>
<td>Captive</td>
<td>0654E</td>
<td>D187A</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td></td>
<td>60D24</td>
<td>M</td>
<td>1</td>
<td>Captive</td>
<td>53723</td>
<td>60B1D</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>R02</td>
<td>D187A</td>
<td>F</td>
<td>6</td>
<td>Wild</td>
<td></td>
<td></td>
<td>4/5/2000</td>
<td colspan="2">Smith Highway</td>
</tr>
<tr class="even">
<td></td>
<td>0654E</td>
<td>M</td>
<td>4</td>
<td>Captive</td>
<td></td>
<td>A7015</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>R03</td>
<td>0507B</td>
<td>M</td>
<td>1</td>
<td>Captive</td>
<td>73D0D</td>
<td>3512D</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td></td>
<td>2410E</td>
<td>F</td>
<td>4</td>
<td>Captive</td>
<td></td>
<td>1612C</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>R04</td>
<td>60B1D</td>
<td>F</td>
<td>3</td>
<td>Captive</td>
<td>84F28</td>
<td>95B34</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td></td>
<td>53723</td>
<td>M</td>
<td>2</td>
<td>Captive</td>
<td>73D0D</td>
<td>3512D</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>R05</td>
<td>F0223</td>
<td>M</td>
<td>6</td>
<td>Wild</td>
<td></td>
<td></td>
<td>4/6/2000</td>
<td colspan="2">Smith Highway</td>
</tr>
<tr class="even">
<td></td>
<td>F4A18</td>
<td>F</td>
<td>5</td>
<td>Wild</td>
<td></td>
<td></td>
<td>3/29/2000</td>
<td colspan="2">Smith Highway</td>
</tr>
<tr class="odd">
<td>R06</td>
<td>37C61</td>
<td>F</td>
<td>4</td>
<td>Captive</td>
<td></td>
<td>F4A18</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td></td>
<td>F3D2F</td>
<td>M</td>
<td>3</td>
<td>Captive</td>
<td>70518</td>
<td>10030</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>R07</td>
<td>70518</td>
<td>M</td>
<td>4</td>
<td>Captive</td>
<td></td>
<td>A7015</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td></td>
<td>10030</td>
<td>F</td>
<td>6</td>
<td>Wild</td>
<td></td>
<td></td>
<td>4/5/2000</td>
<td colspan="2">Smith Highway</td>
</tr>
<tr class="odd">
<td>R08</td>
<td>75125</td>
<td>M</td>
<td>3</td>
<td>Captive</td>
<td>73D0D</td>
<td>3512D</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td></td>
<td>95906</td>
<td>F</td>
<td>2</td>
<td>Captive</td>
<td>F0223</td>
<td>F4A18</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>R09</td>
<td>84F28</td>
<td>M</td>
<td>4</td>
<td>Captive</td>
<td></td>
<td>F4A18</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td></td>
<td>95B34</td>
<td>F</td>
<td>5</td>
<td>Wild</td>
<td></td>
<td></td>
<td>9/1/2000</td>
<td colspan="2">Torrey Pines</td>
</tr>
<tr class="odd">
<td>R10</td>
<td>B067E</td>
<td>M</td>
<td>6</td>
<td>Wild</td>
<td></td>
<td></td>
<td>3/26/2000</td>
<td colspan="2">Smith Highway</td>
</tr>
<tr class="even">
<td></td>
<td>47304</td>
<td>F</td>
<td>2</td>
<td>Captive</td>
<td>70518</td>
<td>10030</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>R11</td>
<td>73D0D</td>
<td>M</td>
<td>5</td>
<td>Wild</td>
<td></td>
<td></td>
<td>7/24/2000</td>
<td colspan="2">Torrey Pines</td>
</tr>
<tr class="even">
<td></td>
<td>3512D</td>
<td>F</td>
<td>6</td>
<td>Wild</td>
<td></td>
<td></td>
<td>11/5/2000</td>
<td colspan="2">Skunk Point</td>
</tr>
<tr class="odd">
<td>R12</td>
<td>51E3E</td>
<td>M</td>
<td>2</td>
<td>Captive</td>
<td>70518</td>
<td>10030</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td></td>
<td>07061</td>
<td>F</td>
<td>6</td>
<td>Wild</td>
<td></td>
<td></td>
<td>5/14/2001</td>
<td colspan="2">Windmill Canyon</td>
</tr>
<tr class="odd">
<td>R13</td>
<td>37E00</td>
<td>M</td>
<td>4</td>
<td>Wild</td>
<td></td>
<td></td>
<td>9/9/2000</td>
<td colspan="2">Skunk Point</td>
</tr>
<tr class="even">
<td></td>
<td>96C2E</td>
<td>F</td>
<td>3</td>
<td>Captive</td>
<td>0654E</td>
<td>D187A</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>R14</td>
<td>E5100</td>
<td>F</td>
<td>4</td>
<td>Captive</td>
<td></td>
<td>F4A18</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td></td>
<td>47E09</td>
<td>M</td>
<td>1</td>
<td>Captive</td>
<td>D3D76</td>
<td>1612C</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>R15</td>
<td>52E0D</td>
<td>F</td>
<td>1</td>
<td>Captive</td>
<td>53723</td>
<td>60B1D</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td></td>
<td>C7B1B</td>
<td>F</td>
<td>1</td>
<td>Captive</td>
<td>73D0D</td>
<td>3512D</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>R16</td>
<td>E3F0F</td>
<td>F</td>
<td>2</td>
<td>Captive</td>
<td>84F28</td>
<td>95B34</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td></td>
<td>C4F63</td>
<td>M</td>
<td>1</td>
<td>Captive</td>
<td>D3D76</td>
<td>1612C</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>R17</td>
<td>D4C78</td>
<td>M</td>
<td>1</td>
<td>Captive</td>
<td>0654E</td>
<td>D187A</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>R18</td>
<td>7792E</td>
<td>M</td>
<td>2</td>
<td>Captive</td>
<td>84F28</td>
<td>95B34</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td></td>
<td>F3950</td>
<td>F</td>
<td>3</td>
<td>Captive</td>
<td>0654E</td>
<td>D187A</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>R19</td>
<td>1612C</td>
<td>F</td>
<td>5</td>
<td>Wild</td>
<td></td>
<td></td>
<td>3/23/2000</td>
<td colspan="2">Smith Highway</td>
</tr>
<tr class="odd">
<td></td>
<td>D3D76</td>
<td>M</td>
<td>5</td>
<td>Wild</td>
<td></td>
<td></td>
<td>3/24/2000</td>
<td colspan="2">Smith Highway</td>
</tr>
<tr class="even">
<td>R20</td>
<td>1271E</td>
<td>M</td>
<td>2</td>
<td>Captive</td>
<td>70518</td>
<td>10030</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td></td>
<td>A180A</td>
<td>F</td>
<td>4</td>
<td>Wild</td>
<td></td>
<td></td>
<td>10/24/2000</td>
<td colspan="2">Skunk Point</td>
</tr>
<tr class="even">
<td>R21A</td>
<td>63F2A</td>
<td>F</td>
<td>2</td>
<td>Captive</td>
<td>73D0D</td>
<td>3512D</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>R21B</td>
<td>B4B2B</td>
<td>M</td>
<td>3</td>
<td>Captive</td>
<td>F0223</td>
<td>F4A18</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>R22A</td>
<td>B7D38</td>
<td>F</td>
<td>1</td>
<td>Captive</td>
<td>53723</td>
<td>60B1D</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>R22B</td>
<td>10445</td>
<td>F</td>
<td>3</td>
<td>Captive</td>
<td>70518</td>
<td>10030</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>R23A</td>
<td>4A7015</td>
<td>F</td>
<td>2</td>
<td>Captive</td>
<td>0654E</td>
<td>D187A</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>R23B</td>
<td>E6D1E</td>
<td>F</td>
<td>3</td>
<td>Captive</td>
<td>73D0D</td>
<td>3512D</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td>RQ1</td>
<td>C586D</td>
<td>F</td>
<td>3</td>
<td>Captive</td>
<td>F0223</td>
<td>F4A18</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>RQ2</td>
<td>25D54</td>
<td>F</td>
<td>2</td>
<td>Captive</td>
<td>73D0D</td>
<td>3512D</td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td colspan="9"><p><sup>1</sup>Pens R01-R12, R21-R23, and RQ1-2 are at
Windmill Canyon site, pens R13-R20 are at Caballo del Muerto site</p>
<p><sup>2</sup>in years, as of fall 2003</p></td>
<td></td>
</tr>
</tbody>
</table>

![](media/image12.wmf){width="5.635433070866141in"
height="3.386220472440945in"}

[]{#__RefHeading___Toc69872240 .anchor}Table 15. Island foxes in captive
breeding facility on Santa Cruz Island.

  -----------------------------------------------------------------------------------------------------
  **Pen**   **ID**   **Sex**   **Age**   **Born**    **Sire**   **Dam**   **Date       **Capture     
                                                                          Captured**   Area**        
  --------- -------- --------- --------- ----------- ---------- --------- ------------ ------------- --
  C01       A4628    M         7         Wild                             3/11/2002    Islay Canyon  

            30B2D    F         5         Wild                             2/27/2002    Cebada Canyon 

  C02       A6D41    M         4         Wild                             2/27/2002    Sauces Canyon 

            D2C13    F         4         Wild                             2/27/2002    Prisoner\'s   
                                                                                       Marsh         

  C03       0786F    F         6         Wild                             3/2/2002     China Pines   

            1415A    M         4         Wild                             3/3/2002     China Pines   

  C04       B506A    M         4         Wild                             1/15/2003    Isthmus       

            C5D0E    F         4         Wild                             1/15/2003    Isthmus       

  C05       36172    M         5         Wild                             2/27/2002    Pelican Bay   
                                                                                       Trail         

            72901    F         4         Wild                             2/27/2002    Prisoner\'s   
                                                                                       Canyon        

  C06       86B1A    M         4         Wild                             2/27/2002    Pozo Canyon   

            86F17    F         4         Wild                             3/10/2002    Pozo          

  C07       D2210    F         3         Wild                             3/11/2002    Cebada Canyon 

            45411    M         4         Wild                             3/1/2002     China Pines   

  C08       44D52    F         1         Captive     45411      D2210                                

            C3E7E    M         1         Captive     A4628      30B2D                                

  C09       1783E    M         7         Wild                             12/4/2002    Coches        
                                                                                       Prietos       

            87035    F         6         Wild                             12/4/2002    Coches        
                                                                                       Prietos       

  C10       D3035    F         1         Captive     45411      D2210                                

            02361    M         1         Captive     A6D41      D2C13                                

  C13       D0926    M         2         Captive     86B1A      86F17                                

  C14       16C30    F         3         Wild                             6/6/2002     Isthmus Pen   
                                                                                       Site          

            F3F0E    M         1         Captive     A6D41      D2C13                                

  C15       E250C    F         1         Captive     86B1A      86F17                                

            01C77    F         1         Captive     A4628      30B2D                                

  ^1^in                                                                                              
  years, as                                                                                          
  of fall                                                                                            
  2003                                                                                               
  -----------------------------------------------------------------------------------------------------