Monday, March 13, 2023

Everything You Wanted to Know About Island Fox Pups

island fox pup, courtesy of I. Rose

Across the Channel Islands, island fox parents are finding hidden-away spots for a den where females can give birth to pups. Most island fox pups are born in April.

How big are island fox pups at birth? Small - about the size and weight of two AA batteries.

What do you call baby island foxes? Pups or kits. At birth their natal fur is a cocoa brown and their ears appear small and rounded. The pup pictured was born at a zoo in 2006–at that time there was a small breeding population in a few zoos. Island fox dens are not disturbed in the wild.

When do pups emerge from the den? Typically in June. When pups come out into the world they have replaced their baby fur with a coat that looks like their parents. Island fox fur

How many pups are in a litter? Typically, 2–3 pups are born in a litter. Play between siblings is an important part of learning to hunt and interact socially. If food resources are abundant, an island fox pair can have up to 5 pups. In years of drought, few pups are born. Drought year, 2021

What sounds do pups make? LISTEN to the sounds of a young island fox pup.

What do they eat?
Like all mammals, island fox pups initially nurse milk from their mother. Gradually, they eat prey brought to them by both of their parents. The parent above is bringing 3 island deer mice back to the den. Both parents teach the pups to hunt and find plant foods. Island fox diet

Are island foxes born knowing how to hunt and find food?
No. All of the island foxes currently in captivity were pups that were separated from their parents and did not learn how to provide for themselves in the wild. Island fox pups need their parents to teach them how to hunt and find food.

Video - Island fox pup reunited with mother

Friday, February 24, 2023

Island Foxes on the Cover of Molecular Ecology

Fox Foto Friday - Island foxes make the cover of another scientific journal!


Friends of the Island Fox congratulates Jasmine Lu on the publication of her paper–"Ear mite infection restructures otic microbial networks in conservation–reliant Santa Catalina Island foxes (Urocyon littoralis catalinae)"–in Molecular Ecology

Working with Dr. Alexandra DeCandia, Lu investigated the connections between bacteria communities and ear mite infection to understand why island foxes on Catalina became so vulnerable to cancerous tumors in their ear canals.

When there's biodiversity in an island fox's microbiome, good bacteria can work together to keep harmful bacteria in check. When there is a lack of diversity, opportunistic pathogens, like Staphylococcus pseudintermedius can become the dominant bacteria in a fox's ear. In combination, ear mite infestation and S. pseudintermedius promote chronic inflammation. More on bacterial imbalance in island fox ear canal

Compounding the probability for serious disease, two strains of Staph bacteria appeared to cooperate in forming a "multistrain biofilm." As the bacterial community deteriorated, other carcinogenesis-promoting microbes rose in prevalence and assumed a keystone role in the microbiome. 

A video of Jasmine Lu discussing her work on "Date with a Fox" will be available soon.

Read the scientific paper

Why does the occurrence of ear mites in Catalina Island foxes initiate this bacterial imbalance? Other island foxes encounter ear mites, but a similar imbalance does not occur.

Those smudgy swabs collected from island fox ears during health checks continue to provide data to compare microbiomes between island foxes. 

Your donations helped to fund this important research for island foxes and the furtherance of scientific understanding of the potential role of bacteria in some cancers.

Friday, February 17, 2023

Fresno Chaffee Zoo Helps Island Foxes

What are those island foxes whispering?

They are spreading the word that the Fresno Chaffee Zoo Wildlife Conservation Fund has provided island foxes with a special end of the year 2022 grant.

$2,400 will help fund Canine Distemper Virus and 

Rabies vaccinations

Canine distemper virus is typically fatal to island foxes. To protect them, a minimum number of 100 island foxes are vaccinated each year on each island.

Because the vaccine that is safe for island foxes only provides protection for 10–11 months, island foxes need to be vaccinated every year.

Vaccination takes place during annual health checks.

Catalina Island has an increased threat of CDV for island foxes. Approximately, 350 island foxes are vaccinated each year on Catalina. FIF funds Catalina shots 2022

This year FIF has the goal to provide vaccine for: 

  • 350 Catalina Island foxes
  • 100 foxes on Santa Cruz
  • 100 foxes on Santa Rosa
  • 100 foxes on San Miguel

With support from the Fresno Chaffee Zoo, Riverbanks Zoo, and private donors like you, we'll vaccinate 650 island foxes in 2023.

We only need to raise another $2,000 to protect 650 island foxes


Friday, January 27, 2023

Virtual Program: How Microbes Influence Island Fox Health and Understanding Island Spotted Skunks

 Join Friends of the Island Fox for a virtual

"Date with a Fox"

Tuesday, January 31 at 6:30–7:30 pm (Pacific Time)

on Zoom

Hear directly from researchers investigating island fox health and biologists working in the field on the Channel Islands.

Jasmine Lu became acquainted with Channel Island foxes while working on her senior thesis at Princeton under the guidance of Alexandra DeCandia, Ph.D. Their work investigated how mite infection can destabilize the microbial community structure in the ear canals of Santa Catalina Island foxes. Their findings have recently been published in the journal Molecular Ecology. Lu will explain their discoveries; she says "It's exciting to be able to contribute to the growing body of knowledge on this fox population!"



Lara Brenner is a FIF Board Member, island biologist for the Nature Conservancy, and member of the Island Spotted Skunk Conservation Working Group. Island spotted skunks co-exist with island foxes on Santa Cruz and Santa Rosa Islands, but little is known about these tiny predators. As island foxes have recovered, how have island spotted skunks been affected? What are we learning about the relationship between these two endemic predators and what more needs to be investigated? Brenner will provide an update on island spotted skunks.

It should be a fascinating evening. We hope you will join us for this free virtual event. Reservations are required.

Watch The Recorded Program

More on FIF and island spotted skunks

Videos of past "Date with a Fox" programs are available here.

Friday, January 06, 2023

Fox Foto Friday - Rain, Races, & Island Foxes

The rains are bringing renewed resources to the Channel Islands! Time to bask in the sun and be hopeful for a positive 2023.

This photo was taken by FIF volunteer Megan Sarrail in December on Santa Cruz Island. 

Avalon 50K Update - Island foxes are sad to report that Cassidy Smith has sustained an injury making her unable to run in the Avalon 50K on Saturday, January 7. The sponsorships she has received will be carried over to a new race and still go to work helping island foxes. 

While the rainy weather isn't the best for all-terrain races, its a good time to spot island fox tracks.


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:

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.