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Wednesday, July 29, 2015

Channel Island Fox Status Update 2015

photo courtesy of M. Solomon
The annual meeting of the Island Fox Conservation Working Group in 2015 reported that the general status of the six subspecies of California's Channel Island foxes is GOOD.

However, four of six islands saw dips or declines in population in 2014. The historic drought and its impacts on food resources is believed to be the cause. Biologists on Santa Catalina have documented a direct connection between rainfall levels and island fox reproduction. Years with drought-level precipitation result in reduced plant food and prey, thereby causing fewer island fox pups to be born or to survive. The extent of drought impact varies significantly by island.

Minimal drought impacts on Santa Cruz Island, 2015
 Despite the drought, recovery of the four endangered subspecies of island fox has been very successful and this spring (March 2015), the US Fish and Wildlife Service (USFWS) announced initiation of a status review of the four subspecies. 

Introduced disease continues to threaten all island foxes and a lack of canine distemper virus (CDV) vaccine safe for use in island foxes has been a major concern for two years. The Working Group took urgent steps, and Friends of the Island Fox participated, to determine the effectiveness of a newly available CDV vaccine.

courtesy of E. Gotthelf
All island fox subspecies are maintaining stable populations and there are no issues which put any Channel Island fox subspecies in eminent threat of extinction. The continuing drought, however, has more severely impacted island foxes on San Miguel and San Nicolas Islands. As seen in the past, each island faces its own concerns and challenges.

Island Fox Update 2015 pdf a specific island-by-island summary
  • San Miguel Island - 520 (low of 15 in the year 2000). Population recovered with over 500 individuals since 2010. Slight population dip. Concern: Threat from new parasites continues, as do drought impacts (see below)
  • Santa Rosa Island - 874 (low of 15 in the year 2000). Population recovery stalled by drought, but stable.
  • Santa Cruz Island - 1,750* (low of 62 in the year 2002). Population recovered and robust with over 1,000 individuals since 2009. No discernible drought impacts.
  • Santa Catalina Island - 1,717 (low of 103 in the year 2000). Population recovered and stable with over 1,000 individuals since 2010. Slight population dip. Concern: Drought impacts and human related impacts, including car strike, and high risk for introduced disease.
  • San Clemente Island - 1,230* (not Endangered). Population stable. Concern: Continued fatalities to automobile strike.
  • San Nicolas Island - 263* (not Endangered). Population has declined ~41% since 2012 because of drought impacts. Concern: Habitat destruction has left island foxes dependent on non-native plants and prey which have declined dramatically in the drought, see below.

The graph above shows population numbers on even years, therefore the dip from 2013 is not represented. For more detailed graphs see the Island Fox Update document. The numbers represented  are the official 2014 population figures reported at the Island Fox Conservation Working Group Meeting 6/16/15. *Population figures represent adults only.

Healthy plant and animal populations fluctuate normally with available resources. Recovered island fox populations naturally dip when there is not enough food, water, or territory. There is a natural limit to the number of island foxes an island can support, also known as carrying capacity.

Low rainfall has impacted food resources across the Channel Islands. However, islands have not been impacted equally. Some islands appear to have greater natural drought tolerance.

As recently discovered by analyzing island-fox diet, Santa Catalina and Santa Cruz Islands have greater native plant biodiversity than the other smaller islands. Native island vegetation evolved with periods of drought. Native plants are better able to survive and produce fruit vital for the survival of island animals. The greater the native plant biodiversity, the greater the survival options for island foxes.

island fox footprints among ice plant on San Nicolas
The island-fox-diet study pointed out that island foxes on San Miguel and San Nicolas Islands were dependent on plant and invertebrate species which had been introduced to their islands, replacing native plant habitat.  Unfortunately, these introduced plant species, especially, ice plant, and the non-native creatures that live in it–snails and earwigs, have declined dramatically during the last two years of extreme drought. The impact has been greatest on San Nicolas Island where average island-fox weight has declined and the population has dropped 41% since 2012.

Restoring native vegetation is the best long term solution for healthy island fox populations on these two islands. (for more on this topic, see the Island Fox Update 2015 pdf document above)

A secondary impact of the drought has been increased complications with parasites. Changes in diet and decreased general health leave island foxes more vulnerable to internal and external parasites. Here again, each island has its own specific parasite challenges. (See Island Fox Update 2015 pdf for details) (Spiny-headed worm on San Miguel Island first detected in 2013).

Introduced disease continues to pose a threat to all island foxes, especially on islands visited by people. Dogs, cats, and introduced species, like raccoons, are all avenues for disease to be transported to isolated and disease-naive island foxes. Efforts to verify the effectiveness of a new CDV vaccine for island foxes is currently underway.

Positive Notes:
courtesy of D. Mekonnen
There are early anecdotal signs that the small amount of rain this spring and summer may be improving resources on the islands. More island fox pups have been spotted this summer than during the last two summers. However, the official impact on the populations will not be known until counting begins in fall.
Monitoring with radio collars continues to provide important information to land managers. Radio collars have helped verify that no golden eagles have returned to eat island foxes on the northern islands. Radio collars were instrumental in determining the cause of island-fox decline on San Nicolas Island. And they continue to provide early warning of disease introduction. Radio monitoring collars will also enable land managers to ethically determine the effectiveness of the new CDV vaccine.

Annual island fox health checks, serology testing, and counting identify threats to island fox survival early, so that actions can be taken to protect island populations.

‘Fox-Saver’ bins on Santa Catalina and the Navy's education outreach on San Clemente are all helping to reduce the number of island foxes hit and killed by cars.

Thank you to the Island Fox Conservation Working Group and all of the important work that has helped island foxes recover from the brink of extinction. Thank you also to the many participants on our June Santa Cruz Island Trip that have allowed us to show you their photographs.

Tuesday, July 14, 2015

FIF Helps Meet Urgent Need For Channel Island Foxes

At the Island Fox Conservation Working Group meeting on June 16th, we learned of a serious threat looming over Channel Island foxes. The Canine Distemper virus (CDV) is highly contagious and deadly to these small canines. It nearly caused the Catalina Island fox's extinction in 1999.

Since that emergency, Channel Island foxes have been vaccinated for CDV with a specific vaccine designed for ferrets. Unfortunately, the vaccine has not been produced for two years. Island land managers have only been able to use vaccine they had on hand, leaving the majority of island foxes unprotected for the last two years.

A new CDV vaccine has recently become available, however it is unclear whether it will be effective for island foxes. There is great urgency to test the new vaccine before fall counting and health check season. This is the only time when a large number of island foxes are handled by biologists on all islands.

Safe capture cages allow island foxes to be captured for health checks
island fox radio-tracking collars
As part of an emergency effort to verify the effectiveness of the new CDV vaccination, five island foxes will be tested on each island. Each of these individuals, which have never been vaccinated for distemper before, will be caught, blood tested, vaccinated with the new vaccine, radio-collared, and released. 

These radio-collared individuals will be caught again a month later and their blood will be tested to verify that they have built-up antibodies against the disease. ID microchips and records on each animal enable biologists to know which island foxes can participate in this test.

This is an extra unexpected cost for each island. Friends of the Island Fox committed to quickly fund:

FIVE radio-tracking collars for Santa Rosa Island ($1,500) 

FIF Santa Cruz Island Trip 2015
Thanks to the participants on our Santa Cruz Island Trip and generous private donors, we have provided these important funds. 
The vaccine is currently being tested across the islands. If the new CDV vaccine provides protection to Channel Island foxes, we may be raising money for vaccinations to protect as many individuals as possible this fall.

Your support helped us to pledge this important financial commitment. Thank You to all of our conservation supporters.

Tuesday, July 07, 2015

Observing Channel Island Fox Behavior on Santa Cruz Island

Santa Cruz Island, Channel Islands National Park
Participants in the Friends of the Island Fox trip to Santa Cruz Island on June 20th had a beautiful day and an opportunity to observe behavior between individual wild Channel Island foxes. Fifteen years ago, when this subspecies of Channel Island fox was facing extinction, such an opportunity was unthinkable.

The island foxes on Santa Cruz Island have made a strong recovery. A baby boom of foxes occurred on Santa Cruz between the fall count in 2007 and 2009. The population jumped from 350 to 1,200. Adult survivorship has been very high, which means we are seeing an increasing number of island foxes between the ages of 5 and 8 years old. These are mature individuals. Island foxes are believed to be in their prime between 2-5 years of age and are estimated to live 8-10 years in the wild.

This trip two elderly animals were noticeable by their broken-down ears and minor injuries to legs and tails. These injuries were most likely inflicted by younger adult island foxes protecting territory. The campground offers an area where infirm animals can potentially find resources, while having some protection from other foxes. 

We observed this older island fox lying down on the ground between campsites where people were active at tables. His coloring camouflaged him well in the dappled shade.

When some campers left their site, a healthy adult island fox checked out their table area. We watched as the slightly larger, but older animal, approached. We didn’t know what to expect.

Submissive behavior of elderly island fox toward another adult.
However, when the older fox got within five feet of the table area, it lowered its head submissively to the younger animal. The younger fox did not chase the older animal or show aggression, yet it physically communicated to the older fox not to approach any closer. Without any direct contact, the older fox was sent off into the bushes.

photo courtesy of Daniel Mekonnen, 2015
We saw 8 - 10 adult island foxes (none were radio-collared individuals). 

We watched island foxes searching for food, retrieving figs, and eating them (Check out the video by Douglas Welch). (The fox jumps up into a shrub at ~2:48) A large percentage of the Santa Cruz Island fox’s diet is fruit.

We’ll have more on the status of the Santa Cruz Island fox in an upcoming Island-by-Island Update. At the Island Fox Conservation Working Group meeting, biologists from The Nature Conservancy reported that a female island fox, born during captive breeding on Santa Cruz, recently passed away at age 12. She is the oldest wild island fox scientifically documented on Santa Cruz Island. Biologists were able to accurately date her age and follow her life because of her ID microchip.

We also had a fantastic encounter with common dolphins on our boat ride home. Hundreds of these colorful dolphins were feeding and swimming right next to us. Look closely and you will see a youngster swimming beside its mother. We saw numerous young dolphins.  (Video of the common dolphins by Douglas Welch).

More photos of the Friends of the Island Fox Trip to Santa Cruz Island:
A special thank you to trip participants Eric Gotthelf, Douglas Welch, Michael Solomon and Daniel Mekonnen for their photos.

Tuesday, June 02, 2015

FIF Funds Three "Fox-Saver" Bins for Catalina Island Foxes

Once again, people working together have helped protect the endangered island fox!

The lethal combination of old trash cans, enticing human trash, and proximity to roads with car traffic has created a growing problem for island foxes on Santa Catalina Island. Double Action to Save Island Foxes

Early winter 2014, eleven Catalina island foxes were hit by cars. Most were near areas of known trash problems.

But thanks to support from a wide range of private individuals and organizations, Friends of the Island Fox has met its goal to raise $6,000 to fund three "Fox-Saver" bins on Santa Catalina Island. The three bins will be placed in high-use areas where fox fatalities have been growing.

Thank you to everyone who helped raise funds for this important project. 

These bins not only help endangered island foxes, they create a healthier environment for people and other island species.

Tuesday, May 12, 2015

Working Together to Save Channel Island Foxes

The success of Channel Island fox recovery is rooted in cooperation among a broad group of government agencies, public and private conservation groups, scientists and researchers, and an active local community. Students, from elementary through high school, have played an active role as Island Fox Ambassadorsraising funds for radio tracking collars, ID microchips, and vaccinations.

This month students from the Buena High Enviromental Club (Ventura, CA) received national recognition for their efforts in restoring native plant ecosystems in Channel Islands National Park. The students from Buena High have also been strong supporters of island fox conservation.

Friends of the Island Fox's motto has always been "Working Together to Save the Island Fox." Many endangered species to not have the benefit of people working in collaboration. We have seen the Channel Island fox rebound from the edge of extinction because people working together can facilitate positive change.

photo courtesy of K. Lampkin
Three Cheers for our active young people and Many Thanks to all the people, near and far, who have helped to fund conservation efforts that have worked!
It all begins with the annual meeting of the Island Fox Working Group in June. Last year we found out about the threat posed to island foxes by trash cans on Santa Catalina. (2014 meeting of the Island Fox Working Group) You helped us respond to this conservation challenge. Any day now we hope to announce we have reached our goal on this effort.

This year drought and biosecurity are on the meeting agenda, both pose threats to stable Channel Island fox populations. Stay tuned for updates from the biologists, veterinarians, and scientists working in the field. 

Thursday, April 16, 2015

FIF 2015 Trip to See Channel Island Foxes

Early summer brings island fox pups out of their dens to explore their world. Parents are busy providing for growing youngsters and teaching them how to find their own food.

The successful recovery of endangered Channel Island foxes means there are greater opportunities to see these rare island predators in their wild habitat

TRIP SOLD OUT as of 5/7/15
Join Friends of the Island Fox for a day of discovery and adventure as we travel to:

Scorpion Cove, Santa Cruz Island
Channel Islands National Park
June 20, 2015

Day Trip Itinerary:  
  • 8:15 AM: Check in with Friends of the Island Fox at the Island Packers’ Ventura Harbor dock, at 1691 Spinnaker Drive, Ventura, for a 9 AM departure to Santa Cruz Island, Scorpion Cove.

  • Arrive on Santa Cruz Island mid-morning and explore with Friends of the Island Fox leaders to view island foxes and other endemic plants and animals. 
  • 4:00 PM: Island Packers’ boat departs Santa Cruz Island, returning to Ventura Harbor around 5:00 PM

Tickets are $65.00 per person. 
(A percentage of the fee will go to support island fox recovery efforts.)
View from the bluff on Santa Cruz Island
Reservations are limited and will be provided on a first come basis. To book reservations, please download the Reservation Form.

Send the completed form with your check, made payable to the "Friends of the Island Fox" to the address on the form.  Reservations will be taken in the order received, and no reservations can be accepted without payment.

At the time of booking you will receive further trip details, including: maps of where to meet, what to pack, suggested clothing and other items of interest. 

Look closely at this photo. Island foxes are smart and curious, food items must be secured at all times.

If you have questions, contact FIF at
or (805) 228-4123

What to remember when visiting the island fox. 

Previous trips to Santa Cruz Island:

May 2014 Trip
June 2013 Trip and Items on the Beach 
May 2012 Trip 

Tuesday, April 07, 2015

USFWS Announces Channel Island Fox's Record Recovery

Channel Island foxes have been in the news! 

The U.S. Fish & Wildlife Service (USFWS) announced the release of the final Recovery Plan for Channel Island foxes on March 11, 2015. They also stated that the USFWS will begin evaluating the current status of the four subspecies which are presently designated as Endangered (the San Miguel Island fox (Urocyon littoralis littoralis), Santa Rosa Island fox (U. l. santarosae), Santa Cruz Island fox (U. l. santacruzae), and the Santa Catalina Island fox (U. l. catalinae)).

Will any of the four endangered subspecies be removed from the Endangered Species List? 

health checks continue to monitor status
That question will not be answered until each subspecies is thoroughly evaluated regarding population health, habitat stability, and potential threats to future survival. Human impacts are a continuing concern, especially on more visited islands like Santa Catalina.

The ultimate determination to downlist any of the subspecies will not occur until at least a year after the status review is completed. Still, there is much to celebrate. As quoted in the press release from Channel Islands National Park:

Due to the remarkable success of the Endangered Species Act, recovery actions by land managers and conservation partners have led to dramatic population increases on all four islands since listing, effectively bringing the species back from the brink of extinction, said Steve Henry, field supervisor of the Service’s Ventura Fish and Wildlife Office. To date, it appears that this is the fastest population rebound due to recovery actions and ESA protections for any land mammal in the United States.

Channel Island foxes are once again highly visible in the wild.
The Endangered Species Act (ESA) has provided the necessary protection and attention to help save four subspecies of Channel Island foxes from extinction.

Thank you to all of the dedicated professionals and concerned private citizens that have contributed to this vital effort. Our motto has never been more true: 

Tuesday, March 17, 2015

The Origins of the Island Fox by Courtney Hofman

(Thank you to our guest blogger, researcher Courtney Hofman) 

photo courtesy of Kevin Schafer
People have long wondered how the island fox first arrived on the Channel Islands. Did they swim? Were they swept out to sea on a piece of debris? Did Island Chumash and Gabrieliño people or their ancestors introduce them? Researchers have proposed a number of possible hypotheses of how the fox arrived but to test each hypotheses we must first examine the data on when foxes arrived on the islands.
For a long time scientists thought that island foxes had been on the islands for at least 16,000 years and some argued they had been there as early as 40,000 years ago (Aguilar et al. 2004). This is well before people arrived on the islands some 13,000 years ago. These early date estimates were based on island fox bones recovered from paleontological sites. However, direct radiocarbon dating of these same fox bones indicate that they are less than 7000 years old (Rick et al. 2009). Additional radiocarbon dates on island fox bones recovered from archaeological sites indicate that island foxes may have arrived on the islands approximately 7100 years ago, well after people.
When combined with radiocarbon dates, genetic data can also be used to test hypotheses about the origins of the island fox. Mitochondrial DNA is inherited from a fox’s mother and can tell us a lot about the history of the island fox. In my recent study, mitochondrial DNA was sequenced from 185 island and mainland gray foxes to explore how these different populations are related to each other (Hofman et al. 2015).

Median-Joining Network of Island and Mainland Mitochondrial DNA
By comparing these DNA sequences, we know that northern island (Santa Cruz, Santa Rosa, and San Miguel) foxes are closely related to each other while the southern island populations are more distinct (Santa Catalina, San Clemente and San Nicolas). Together with radiocarbon dates, mitochondrial DNA suggest that island foxes arrived on the northern islands between 9200 and 7100 years ago and were likely quickly moved by humans to the other islands. We cannot yet say how the foxes first arrived on the islands. More genomic and archaeological data are needed to distinguish between a human or natural introduction. 

  • Aguilar, A., Roemer, G., Debenham, S., Binns, M., Garcelon, D. and Wayne, R. K. (2004). High MHC diversity maintained by balancing selection in an otherwise genetically monomorphic mammal. Proc. Natl. Acad. Sci. U. S. A. 101: 3490–3494.
  • Hofman, C. A., Rick, T. C., Hawkins, M. T. R., Funk, W. C., Ralls, K., Boser, C. L., Collins, P. W., Coonan, T., King, J. L., Morrison, S. A., Newsome, S. D., Sillett, T. S., Fleischer, R. C. and Maldonado, J. E. (2015). Mitochondrial Genomes Suggest Rapid Evolution of Dwarf CaliforniaChannel Islands Foxes (Urocyon littoralis). PLoS ONE 10:e0118240.
  • Rick, T. C., Erlandson, J. M., Vellanoweth, R., Braje, T. J., Guthrie, D. A. and Stafford Jr., T. W. (2009). Origins and Antiquity of the Island Fox (Urocyon littoralis) on California’s Channel Islands. Quat. Res. 71: 93–98.

Tuesday, March 10, 2015

What Color Is An Island Fox?

photo courtesy of Kevin Schafer
What color is an island fox?

It might seem an easy question, but there is more to the color of a Channel Island fox than initially meets the eye.

At first glance an island fox (Urocyon littoralis) appears to be a mixture of white, reddish or rust, and gray markings, with a little black. The island fox's ancestor, the gray fox (Urocyon cinereoargenteus) has similar coloration, though typically less rust.

The primary color on an island fox is a grizzled gray along its back.

island fox back

This cryptic coloring provides very successful camouflage because it is not a solid color.

There is an underlying downy fur of a light tan, interspersed with long guard hairs. While some guard hairs are black, others along the back are variegated in color. A guard hair may be black, with a thin bit of brown, then white, and finally tipped in black. The combination of colors creates an overall appearance of gray.

island fox pup in the fog
However, the multiple layers of varying color create a break-up pattern; there is no solid color for the eye to discern. This allows the island fox to disappear into landscapes with low light levels–shade, twilight or fog.

island fox on mottled flooring at a medical facility

This characteristic also makes it challenging for auto-focus on a camera to successfully focus on island foxes. The fox in the photo to the left is actually standing, but it is hard to visually distinguish its back from the floor.

The variability in island fox fur also means that small hereditary changes in the fur can make large general changes in appearance. 

A little less black at the tip of the guard hairs and the overall appearance is much lighter. Such an island fox may appear more beige or brown and blend in better with the environment of the southern islands: San Nicolas or San Clemente. Lighter colored individuals may also be more successful hunting sand dune or beach habitats.

northern island foxes during captive breeding 2000-2006

A bit more black on the tip of the guard hairs and the overall coloring appears much darker and more gray. This coloring is more beneficial in habitats with denser vegetation, Santa Catalina, Santa Cruz and Santa Rosa Islands.

The plasticity of their camouflage coloring has helped island foxes remain successful hunters in varied Channel Island habitats.


Friday, February 06, 2015

Double Action to Save Catalina Island Foxes

Help Friends of the Island Fox reduce a major threat to the Santa Catalina Island fox (Urocyon littoralis catalinae): human trash

Yes, eating human food is bad for island foxes. Adults dependent on human food fail to teach hunting skills to their offspring. (Island fox diet) However, the greater threat is the attraction of trash and the behavior island foxes engage in to reach readily available human food waste.

The first problem is that standard trash and recycling containers pose a threat to these small foxes. This old trash can, next to a fence, allows an island fox to easily climb inside. The fox's diminutive size means it can easily fit through openings and fall into trash receptacles. 

Aging bins are an enticing hazard.

photo courtesy of Lesly Lieberman and CIC
Once inside, island foxes have a difficult time getting out of these containers. Trash can lids are designed to push open from the outside. Catalina Island biologists have documented numerous cases of island foxes dying inside trash cans.


photo courtesy of Julie King, CIC
The second issue is that accessible trash cans encourage island foxes to cross roads and enter dangerous areas. Notice the island fox under the left side of the trash can pictured here. It is pulling trash out of the rusted bottom of this can. 

Catalina Island Conservancy biologists Julie King and Calvin Duncan report: 

Between April and May 2014, four foxes were hit and killed by vehicles in close proximity to open trash cans near Bird Park in Avalon and two more were hit and killed there in November. It is unknown how many other foxes may have been hit by vehicles in the area but did not immediately succumb to their injuries, and were therefore not accounted for.

courtesy of Julie King, CIC
Car strike has become the greatest killer of island foxes on Catalina Island. The island fox pictured to the right was killed by a car, notice the trash can on the other side of the road (to the left). Clusters of unnecessary island fox deaths are occurring in areas adjacent to public spaces with numerous trash cans.
New "Fox Saver" trash bins

But there is a solution to the double threat: trash bins that island foxes can not access.

“Fox Saver” bins are the same sturdy containers used at Yellowstone and Yosemite National Parks to keep bears out of human trash. Opening the bin requires long human fingers. There is no opening for an island fox to easily enter.

Once the attraction of available human food waste is eliminated, we hope there will be less motivation for island foxes to cross roads, and maybe less attraction to venture into Avalon.

Purchasing these all-steel bins, shipping them to Santa Catalina Island, and installing them on a cement pad comes with a sizable price tag. Each bin costs $2,000. The Catalina Island Conservancy has a goal of replacing 150 trash bins across the island.

Friends of the Island Fox aims to raise $6,000 to fund three “Fox-Saver” bins to be placed in
Avalon's Bird Park area. This should actively reduce island fox deaths along one of Santa Catalina's busiest roads. Your donation will help meet this goal and save island fox lives.

The Catalina Island fox is making a strong recovery, but its current restored population combined with growing human activity  has increased direct human threats to island fox survival. 

Help us make a positive impact by funding 
"Fox Saver" bins!