Tuesday, December 13, 2022

FIF Research Grant Will Investigate Island Spotted Skunk Genome

Meet Julia Owen, a researcher at the University of California, Davis Mammalian Ecology and Conservation Unit. 

FIF's 2022 Research Grant will help process samples in Owen's effort to decode the genome of island spotted skunks and determine their genetic history. When did this island endemic diverge from a mainland ancestor and which mainland spotted skunk is their closest ancestor?


Little is known of the island spotted skunk that shares habitat with island foxes on two islands–Santa Rosa and Santa Cruz. Because island spotted skunks are nocturnal and reclusive, basic knowledge like diet, social behavior, and even when these tiny predators reproduce remains unclear. Yet, island foxes and island spotted skunks have an impact on each other. More on foxes and skunks sharing habitat


Currently island spotted skunks (Spilogale gracilis amphiala) are considered a subspecies of western spotted skunks. Physically they all appear similar to human eyes and, until recently, the relationship between spotted skunks across North America has been regarded as primarily a division of western and eastern species. New genetic research, however, is revealing that there are substantial genetic differences and even reproductive variation between the two groups–western spotted skunks have delayed implantation of embryos and eastern spotted skunks do not. "Delayed implantation" means that spotted skunks in difficult desert, mountain, or isolated environments can breed at a time that is easier to find a mate, but the embryo within the female will stop development for a period of time and then resume development so that birth will occur at a more optimal time for success.

"Through the use of genetic and genomic tools, " Owen explains, "it is now becoming clear that island foxes and island spotted skunks have been coinhabitants of Santa Cruz and Santa Rosa Islands for thousands of years. Investigating the evolutionary history of island spotted skunks will also provide information on the evolutionary ecology of island foxes on the northern Channel Islands."

This work could also help us understand if island spotted skunks should be considered a unique island species, like island foxes. Julia Owen adds, "shedding light on the distinctness of each population of island spotted skunks may help inform and increase conservation efforts on each island."

Friends of the Island Fox participates in the Island Spotted Skunk Conservation Working Group. For more about island spotted skunks check out their website: www.islandspottedskunk.com

See Ellie Bolas talk on preliminary research on island fox and island spotted skunk interactions

Tuesday, December 06, 2022

Running for Island Foxes!

Cassidy Smith has found a new way to help raise funds and awareness of island foxes!

On January 7th, 2023

Cassidy is running in the Avalon 50K 

(= to 31 miles!)

And she'll be doing it to benefit island foxes!


The course will take her and more than 700 other participants along Catalina Island's mountain ridges and down canyons, from Avalon to Little Harbor and back. Along the way island foxes will be cheering Cassidy on!


You can join-in the effort and sponsor Cassidy through FIF's Special Event Sponsorship page hosted on Givebutter 

Her goal is $1000 and FIF hopes to match Cassidy's fundraising! 

$2000 will vaccinate 100 island foxes on Catalina Island.

Help Cassidy raise funds for island foxes 

each step of this ultra-marathon!

Friday, October 21, 2022

Radio Collars Going On Island Foxes!

Radio-tracking collars are the primary way that island fox survival is monitored across the Channel Islands.


12 new radio collars and 21 refurbished radio collars funded by your donations are going on island foxes RIGHT NOW on Catalina Island.


Across Catalina Island wildlife biologists are giving island foxes health checks. Weighing them, checking their ears, 


and overall condition.

Meet wildlife biologist Emily Hamblin and hear how she gives health checks to island foxes. "Date with a Fox" program (video recording)

Island foxes also receive vaccinations and have a sample of their blood drawn looking for signs of exposure to other diseases.

Island foxes faced near extinction on four islands twenty-two years ago. One of the causes was introduced canine distemper virus. Island foxes can be vaccinated for this disease, but new diseases arriving on the islands remains one of the greatest threats to this island species. The word for this is "biosecurity." 

Everyone that visits the islands plays a role in biosecurity. See what you can do  

Friday, October 14, 2022

Fox Foto Friday - Island Foxes Say: "Happy 50th"

Happy 50 Years of protecting Catalina Island's wildlife and wild places to the Catalina Island Conservancy (CIC).


This photo says it all. Twenty-three years ago Catalina Island foxes faced extinction from introduced canine distemper virus. Today Catalina's island foxes thrive.

Friends of the Island Fox works with CIC to help vaccinate island foxes, provide radio collars for monitoring survival and investigate threats from other virus introductions.

Protecting island foxes takes a community.  

Friday, September 16, 2022

Do You Remember This Fox? It's F257


Even with her face covered, F257 from Santa Rosa Island is a stunning island fox. Her coat is lustrous, her weight is good, she looks healthy. The mask/muzzle helps keep her calm during her health check.

You might remember F257 from 2021, 2020, and 2019

She received her first health check when she was a pup in July of 2019. In the winter of 2019, she was fitted with her first radio tracking collar.

F257 continues to live in the Old Ranch area on Santa Rosa Island. This is the same area where she was born and first seen.


In August, National Park biologists were happy to see F257 during island-wide counting of island foxes. Biologist Juliann Schamel says "[F257] has been captured every summer on the [Old Ranch] grid, and has never shown signs of having reproduced, although she is in good condition/health. She's still quite young and most foxes on Rosa did not reproduce in 2020 or 2021, so this isn't surprising." 

Low rainfall frequently correlates with fewer resources and female foxes tend to have fewer pups or no pups. Santa Rosa Island may also have reached maximum population size. F257 may not be able to find a mate or adequate territory to support having pups. Being single, may also be a choice. She looks great.

You can see from her data sheet that F257s health check and the replacement of her radio-collar took only 12 minutes.

After two and a half years, F257's radio collar needed a new battery. Her collar was replaced and the old collar will be refurbished so it can be used again. In the video below, you'll see F257 be released after her health check.


Did you notice F257 looked back at the biologist multiple times. Maybe she recognizes the biologist, too. 

With her radio-tracking collar F257 is helping to monitor island fox survival on Santa Rosa Island. 

Your donations to Friends of the Island Fox fund radio-tracking collars and important research across the Channel Islands.

Friday, September 09, 2022

Zoos Helping Island Foxes

Sometimes you have to look behind the scenes to see the important role that zoos play in wildlife conservation. The island fox has several important zoo friends.

Fresno's Chaffee Zoo

Fresno's Chaffee Zoo has been a vital partner in island fox recovery and health for 16 years. It started with a few zoo keepers committed to helping island foxes and a donation for a radio-tracking collar. 

When the zoo established their Wildlife Conservation Fund, Friends of the Island Fox was a 2014 grant recipient. Over the years, the FCZ Wildlife Conservation Fund has funded not only radio collars, but vaccinations, equipment for safe capture of island foxes, important evaluation of island fox blood samples for evidence of disease and other critical health measures.

In January of 2022, the FCZ Wildlife Conservation Fund provided a special one-time grant that funded the refurbishment of 15 radio collars for Santa Cruz Island foxes. These collars were all placed on island foxes over the last month. The grant also helped fund vital testing for disease among island foxes.

Friends of the Island Fox just received our FCZWCF grant of $3,200 for 2022. This funding will go toward health monitoring and/or vaccinations for island foxes.


Santa Barbara Zoo

The Santa Barbara Zoo was the first to come to the aid of endangered island foxes and they participate in the Island Fox Conservation Working Group. Keepers and veterinary staff helped develop the care and feeding protocols for island foxes in captive breeding facilities from 2001–2006. The zoo has provided a home for a few island foxes and was the first to successfully breed island foxes in captivity. Today, all of the island foxes living in mainland zoos are rescued wild individuals that do not have the skills to survive in the wild. 

Lewis and Clark (above) are brothers who were abandoned by their parents in the midst of drought on San Clemente Island. Today these two island foxes play an important role for their wild relatives. Because they live in a controlled environment with ready access to veterinary care, they are health advocates for other island foxes. They provided samples to the island fox microbiome research study. 

Early in the pandemic it was discovered that Covid-19 could be passed to canines. As the pandemic grew there was concern for island foxes in the wild. Could biologists handle island foxes for health checks as they had in the past? Might island visitors pass Covid-19 to island foxes?

Island foxes are very susceptible to introduced diseases. Many vaccinations for dogs are not safe for island foxes. In the controlled environment of the Santa Barbara Zoo, Lewis and Clark were vaccinated against Covid-19. They had no ill side-effects. Zoo veterinarians monitor whether the vaccine continues to protect the two foxes. If necessary we know island foxes can be safely vaccinated for Covid-19.

Beau at the Living Desert

Island Foxes at other Zoos

Living Desert in Palm Springs - Home to Beau (above) a male abandoned as a pup during drought on San Clemente Island

Female gray fox and island fox sisters at CALM

California Living Museum in Bakersfield - Home to two sisters (above) abandoned as pups during drought on San Clemente Island

San Diego Safari Park - Home to Sage a female with a chronic health condition from Catalina Island

FIF is thankful for the continued support of island fox conservation from our Zoo Friends.

Wednesday, August 10, 2022

FIF Research Grant Deadline for 2022 Approaches


Small pieces of island fox whisker can reveal big data on island fox diet and behavior. 

Analyzing stable isotopes in slivers of island fox whisker, Juliann Schamel (Research grant recipient 2018 and 2019) has been uncovering the range of diet eaten by island foxes, drought impacts on their diet, and a new understanding of how some island foxes use marine resources.

Your scientific research could also benefit island fox survival and the management of rare and endangered species.

Friends of the Island Fox is accepting applications for the 2022 Island Fox Research Grant through August 29, 2022. 


More about current island fox research and recent grant recipients.

Your donations help support vital island fox research. 

Friday, July 08, 2022

2022 Island Fox Status Update

Island fox populations remain stable, but continuing drought raises concerns.

This is the update from across the Channel Islands as compiled from notes by Friends of the Island Fox at the Island Fox Working Group Meeting held May 11, 2022 at the Santa Barbara Zoo (hybrid meeting).

Reported population numbers are official estimates from each land manager as calculated during the 2021 counting period. (How are island foxes counted)


Overview: While adult island foxes appeared healthy across the islands in 2021, record low rainfall correlated with an extremely low number of births. As California and the Channel Islands face a second year of drought in 2022, island foxes will experience greater survival challenges. Concern is heightened for the San Miguel and San Nicolas Island foxes because they are naturally smaller populations and the native plant communities on these islands have been slow to recover from historic overgrazing.

The leading threats to island foxes in 2022 are:

  • climate warming: increasing regional temperatures and decreasing annual rainfall reduce food resources, decrease reproduction, increase wildfire threat, and promote greater parasite numbers
  • biosecurity: threats of introduced viruses, disease, and/or non-native animal species

Greatest Concern: The connection between island fox reproduction and rainfall was first documented on Catalina Island. A lack of rainfall reduces resources and depresses island fox reproduction. This is a natural way for canine populations to adjust downward so that individuals can find adequate food and territory.

Notice how the yellow bar (Santa Cruz, above) and the red bar (Catalina) decline from 2017 to 2018, a year of extreme drought. The following year (2019), above normal rainfall returned and all island fox populations benefited. While 2020 provided a minimum average rainfall of 12 inches, it was followed by historic low rainfall in 2021. Most island fox populations adjusted downward.

The 2021 estimates for Santa Rosa and Santa Cruz Islands may be slightly inflated. It is possible that in the face of food instability, a greater number of adult island foxes may have gone into capture cages for a meal. At the same time, the number of pups documented on these two islands was only 2 and 3 individuals, respectively. There was virtually no observed reproduction in 2021. Expected age range models can get out of balance when no pups are born into the population and the surviving island foxes continue to age. 

Further impacts from drought and increased temperatures: 

  1. San Nicolas Island recorded a decline in fox body weight 
  2. Multiple islands cited increases in fleas, lice, and/or ticks
  3. Activity research noted a possible trend in foxes shifting to increased nocturnal behavior during hotter summers

Island foxes enter a second year of drought with minimal reserves. 

 Smaller Islands:

The smaller islands remain stable, but did adjust downward after two years of reduced rainfall. Both San Miguel (lime green) and San Nicolas Island (pink) appear to be balancing out at lower population levels than in the past. This may be due to reduced food availability and a diet shifting away from nonnative ice plant which died off in earlier drought years.

San Miguel Island - (lime green line) The lower density of foxes on this island combined with higher levels of moisture from fog supported more pups than on the larger islands. Adults had a 85% probability of surviving the year. 

San Nicolas Island - (pink line) Lower density also benefited island foxes on this island–11 pups received health checks. While still a low number, this was the highest pup count seen across the islands in 2021. Adenovirus (dog flu) was unexpectedly found in a high number of foxes on this island, but fortunately no fatalities were found. The source of the virus's introduction remains a mystery. Friends of the Island Fox worked with U.S. Navy biologists to educate Navy personnel about island fox behavior and life cycle. The number of island foxes hit by cars was reduced from the same period of time the previous year.

San Clemente Island - (blue line) Island foxes appeared healthy, but only 3 pups were recorded in 2021. Concerted education efforts by Institute for Wildlife Studies biologists and the U.S. Navy dramatically decreased car strike fatalities in 2021 - though the low number of young foxes may have also helped decrease the number of animals on the roads.


Larger Islands:

island fox being vaccinated


Santa Catalina Island - (red line) The recovery of this population is well established and the population naturally fluctuates around 1500 individual island foxes. Biosecurity is a daily challenge. Vaccination efforts have increased to every fox in-hand except sentinel foxes. In 2021 Adenovirus increased to 80% of the fox population; fortunately no fatalities are known. Testing for introduced disease is vitally important and there are hopes to increase this effort.

Santa Cruz Island - (green line) The recovery of this population is also well established. The population naturally fluctuates around 2,300 individuals with a fairly high density of 9.86 foxes per square kilometer. [for reference Disneyland's Magic Kingdom in Anaheim, CA is 1 sq. km] Biosecurity is also a heightened concern on this island. As well as monitoring with radio collars, new wildlife cameras are being established at island entry points to watch for introduced species that could be carrying disease. Adult survival rates declined to a 69% chance of surviving the year and there is concern that continuing drought will challenge adult survival in 2022.

Santa Rosa Island - (pink line) With the plateauing of the island fox population on Santa Rosa Island, it is believed this island has fully recovered and reached carrying capacity. The next few years should see adjustment toward a naturally sustainable population level. Currently the island has a density calculated at 12.4 foxes per square kilometer; a very high density. Continuing drought could impact the ability of older island foxes to maintain territory and access to resources. Two GPS research projects supported by Friends of the Island Fox will be watching the movement, diet, territory size, and interaction of island foxes very closely this summer on Santa Rosa Island.

*Note line graphs show population estimates from even years, with the exception of the most current year 2021. Population graphs with all years show greater fluctuation. See bar graph "Island Fox Populations of the Last 5 Years" at top of page.

Friday, July 01, 2022

Testing for Disease Threats on Catalina Island

At the Island Fox Working Group Meeting in May, FIF provided $4,500 to support testing for disease antibodies on Catalina Island during 2022 island fox health checks.

This effort spots viruses introduced to the island. If a fox comes in contact with a virus, its immune system will develop antibodies to try and fight off the disease.

This is similar to how COVID-19 is tracked in humans.


We know this effort is important because FIF funding in 2021  helped biologists on Catalina Island discover that antibodies for Adenovirus (dog flu) were present in 80% of Catalina Island foxes. This is a steep increase from 2020. 

While no island foxes are believed to have died from Adenovirus, this rapid increase reminded everyone of how canine distemper virus would spread if it reoccurred on the island and foxes were not vaccinated.

A blood sample might not seem as exciting as a radio collar, but both are important to island fox survival. This effort was funded by donors like you and a one-time grant from the Fresno Chaffee Zoo Wildlife Conservation Fund.

Your donations help protect island foxes from disease.

Please donate today

Friday, June 24, 2022

Friends of the Island Fox Vaccinates Island Foxes

You're making a HUGE difference for island foxes this summer.

Biosecurity is a major concern across the Channel Islands. Disease, especially viruses, can be introduced through unvaccinated pets, people, and wildlife species that are not native to the islands.

The island foxes on Catalina Island face the greatest potential biosecurity threat because their home is visited by millions of people

Friends of the Island Fox just purchased over $5,100 worth of vaccines to vaccinate 350 Catalina Island foxes this summer. Island foxes captured for health checks will receive two vaccinations:

  • Canine distemper virus: It's the equivalent of measles in humans. This virus is highly lethal to island foxes and killed over 90% of the Catalina Island fox population between 1998–2000. Even with a great deal of human assistance, it took until 2016 for the population to recover.
  • Rabies virus: Rabies is lethal to island foxes and dangerous to humans. Just like with dogs, the best protection is prevention.  


It costs $20 to vaccinate and protect an island fox.

Make A Difference 

Your donations help island foxes

This vaccine effort was funded by donors and a grant from the Fresno Chaffee Zoo Wildlife Conservation Fund.

Biosecurity measures you can take when traveling to the islands


Saturday, June 11, 2022

GPS Tracking Collars vs Radio Telemetry Collars

Radio telemetry collars are used across the Channel Islands to monitor island fox survival. These collars help biologists locate an island fox in real time and they give a specific signal when a fox is alive and moving around. 

Fifty to sixty island foxes on each island wear radio telemetry collars. Most of these are sentinel foxes. FIF funds radio collars to monitor island foxes.

GPS tracking collars record exact GPS coordinates. They have an additional antenna (that black bump at the top). Location data is recorded at designated times or time intervals over a specific amount of days, weeks, or months.

See the GPS data comparing island fox movement and island spotted skunks on the same hillside.

"Date With a Fox" May 1, 2022 Brian Cypher, Ph.D., Director and Research Ecologist CSU Stanislaus' Endangered Species Recovery Program talks about how GPS data provided important information on endangered San Joaquin kit foxes and how this same technology can benefit island foxes.


Friends of the Island Fox is supporting two research projects starting this summer to investigate island fox territory and habitat use on Santa Rosa Island. 

Katie Elder will replicate a GPS investigation of island fox territory size that was initially done when the population was under 400 individuals. Will territory size be different with the current estimated 2600 island foxes? Have these foxes reached the island's carrying capacity?

Juliann Schamel will also track island fox movement and territory size with GPS collars. She'll integrate her findings on diet with how individual island foxes are moving in the environment. Do all island foxes have access to beach resources or are there distinct areas and resources used by individual island foxes?  

In combination, this will be the largest investigation of island fox movement and territory size ever initiated. 

Your donations make this important research possible. 

Please consider donating today

Friday, May 06, 2022

Island Foxes and Carrying Capacity

"Carrying capacity" is a term used in biology to describe when a habitat has reached the maximum population of a specific species that can be supported by the habitat's resources.

Think of a table with a platter of cookies. If there are more cookies than people, individuals will recruit others to enjoy the cookies; the population at the table increases. If there is just one cookie for each person, carrying capacity has been reached. If there are more people than cookies the table has exceeded its carrying capacity. People who need cookies will have to leave the table and go to another habitat; there aren't enough resources to support the larger human population.

Seeing three island foxes in such close proximity, as in the image above, is unusual.  A unique weather situation provided unusual resources.

Because island foxes live on islands, they are definitively confined to the resources of their habitats. They can not migrate to another location when resources or climate become challenging. Carrying capacity, however, isn't a strict number. The Channel Islands are wild natural places and island resources vary from year-to-year depending on rainfall and weather. 

Island foxes on Santa Rosa Island (pink line, in graph) have been increasing as they recovered from near extinction twenty-two years ago. In 2021, biologists documented the first estimated decrease in the Santa Rosa Island fox population. (Official 2021 population numbers will be available later this month.) This could be signally that the population estimate of 2,657 in 2020 was a larger population than the island's resources could actually support.

How does the population adjust down? Older island foxes (8–10 years old) may have a more difficult time surviving. They may be pushed out of their established territory by younger foxes. 

In addition, reproduction can slow down, decreasing the natural population replacement of individuals. We know that very few pups were documented on Santa Rosa Island in 2021. 

This female fox on Santa Rosa Island (right), identified as F257, was captured in 2019 as pup and then again in 2020 and 2021. At two years old, F257 is in her breeding prime, but she has yet to produce pups. This most likely is in response to limited resources.

Santa Rosa Island was extremely dry in 2021. Canines are adapted to produce offspring in balance with the amount of available resources. A female island fox with lots of food resources can produce five pups in her annual litter, but if there aren't enough resources or available territorial space to keep pups safe, her body can reabsorb embryos and give birth to no pups. 

Carrying capacity can sound ominous, but it doesn't mean that island foxes will experience a die-off event because they have reached a specific population number. 

If we look at Catalina Island (red line, in graph above), we can see that the island foxes on Catalina reached carrying capacity around 2013–2014. A healthy population on this island appears to be between 1,800 and 2,200 island foxes. During years of normal rainfall, resources increase and so do island foxes. Drought years, like the winter of 2015–2016, can result in natural fox fatalities and less reproduction. The population gradually adjusts down. When normal rainfall returns, the population rebounds. This is the natural fluctuation expected in a wild population. 

Now that the Santa Rosa Island fox population is at a high and has potentially reached carrying capacity, 2022 is the perfect time to re-evaluate territory-size and fox movement to access various island resources. Collecting GPS tracking data this summer will provide valuable data on territory, the current interactions between individual foxes, and how they access resources in their habitat.

Your donations are helping fund two important GPS-tracking studies on Santa Rosa Island this year.

FIF is also taking applications for the FIF 2022 Research Grant.