Not Every Fox on an Island is an Island Fox

Friends of the Island Fox educators had a great question from a student in the Oak Park School District in California.

Are the foxes on the San Juan Islands in Washington island foxes?

Monascherie for San Juan Visitors Bureau

San Juan Island in Washington does in deed have a fox population; it's the only island along the coast of Washington that does.

The foxes range in color from tawny red to silvery black, but if you know your foxes there is a distinct characteristic that tells you these foxes are very different from the Channel Island fox. The tail tip is white! 

How to ID North American Foxes

The foxes on San Juan Island are red foxes (Vulpes vulpes). 

The story of the San Juan Island foxes has some similar plot points to island foxes: 

• introduction of non-native species to an island
  
• damage to an island ecosystem
• a search for ecosystem balance

In the 1800s, a lighthouse was built on San Juan Island to help ships avoid dangerous waters. (Just like the lighthouse on Anacapa Island). Transporting fresh food to the island was costly, so in the late 1800s, European rabbits were introduced to San Juan Island to provide a fresh meat source for lighthouse keepers.

Without any natural predators on the island, the rabbits quickly began devouring the native island plants. The island ecosystem was crashing. There were too many rabbits for the people to control. It's believed that some time around 1930, red foxes and/or red foxes bred to have black fur for the fur industry were introduced or set free on San Juan Island. It was hoped that the red foxes would control the rabbit population and also provide foxes for people to hunt.

The red fox population on San Juan Island is fairly small, but they have controlled the European rabbits and, fortunately, they have not had a negative impact on other native island species. The island has returned to a tenuous balance and the red foxes are now protected on San Juan Island. 

The red foxes have been isolated on San Juan Island for almost 100 years. 

Will they develop island adaptations? Will they become island dwarfs over time like the island fox? How long will it take for them to evolve into a new species? Only time and evolution can tell.

Island foxes on California's Channel Island remain the only island-endemic fox species in the United States.

If you have a good question about island foxes send FIF an email at info@islandfox.org.

Island Fox Microbiome at the Smithsonian!

FIF's 2020 Research Grant recipient Dr. Alexandra DeCandia recently spoke about her work investigating the island fox microbiome. 

Watch the video of the program

Here's a behind the scenes look at her process extracting the DNA of different microbes from the island fox swab samples.

Dr. Allie reports: 

I inventoried over 800 swabs and over 300 blood samples collected from Channel Island foxes and island spotted skunks in 2020. I then extracted DNA and prepared samples for microbiome sequencing (a process called "library preparation"). The last step of the library preparation is cleaning the library–in essence, removing all of the DNA fragments that I don't want to ultimately sequence.

Although it may seem like a straightforward process, this took a bit of troubleshooting. After a few failed attempts, I worked with the lab manager at the Smithsonian National Zoo's Center for Conservation Genomics to learn how to run an "eGel". In this approach, you put your library in an agarose gel (which looks like a think rectangle of gelatin), run an electrical current through the gel to separate DNA fragments based on size...

(under UV light, the fragments look like glowing bands of the gel), and then pull out the band you want to sequence (in my case, fragments roughly 400 base pairs in length).

Then the DNA had to be treated to remove "gel particles and other potential contaminants."

Overall, this was a nerve-wracking process, but thankfully it worked!

Dr. Allie has submitted all seven sequencing libraries to the Princeton University Genomics Core Facility for sequencing. She reported on some preliminary findings during her "Date with a Fox" presentation. This is Fox Science at work! 

Your donations support this cutting-edge science that will provide important information regarding island fox health.  

Swab collection continues.

What is a microbiome? and Why is this important for island foxes?

A San Miguel Island Fox Gets A Radio Tracking Collar

San Miguel Island is a windswept, treeless place. The most northwest of the California Channel Islands, and part of Channel Islands National Park, few people visit, but this island provides vital habitat for the rare San Miguel Island fox.

This fall during fox counting, a young male island fox was captured in this area of dunes and sage. Few pups were captured in 2021 on any of the Channel Islands; continued drought conditions reduced available food resources resulting in fewer pups being born. 

Male M515 is one of the few island fox pups documented in 2021. Following his health check, he was fitted with a radio-tracking collar funded by Friends of the Island Fox. This radio collar will enable biologists to monitor his survival and track his movement. 

As a young adult, M515 has yet to establish his territory. Will he stay in this dune area or roam to more shrubby parts of the island?

Will he stay close to the coastline or will he find a home in the island's interior? Which area will provide the greatest quantity and quality of resources? How large of a territory will he patrol? These are important questions that researchers are trying to answer.

Young male island foxes are on the move in autumn and winter. Is his priority finding a territory or a mate? We don't really know. As a youngster, however, he will have competition for territory from other males. The population of island foxes on San Miguel Island was estimated at 277 individuals in 2020. (2021 population estimates are currently being calculated.) Because the current population is down from an estimated high of 453 in 2019 (an average rainfall year), M515 may have an easier time finding a territory of his own.

His island is a beautiful, if rugged place to live. If he's lucky, winter rains will bring renewed plant growth and prey species. He might find a mate and father pups before his first birthday in April.

Through it all, his radio collar will allow biologists to track his survival and see where he ends up on the island. If you donated to Friends of the Island Fox - M515 might be wearing a collar you helped provide! 

Every Donation Helps Island Foxes

More about San Miguel Island

Fox Foto Friday - This Is Island Fox Science

Fresh from the fox swabs...This past week, Friends of the Island Fox had the opportunity to spend some time in the field with the biologists of the Catalina Island Conservancy during their final days this season counting and providing island foxes with health checks.

During health checks, samples, like the one shown above, were taken. (how are island foxes swabbed?)

Soon these swabs will be boxed up and sent across the country to enrich the data set of Dr. Alexandra De Candia. During FIF's first virtual "Date with a Fox," Dr. Allie shared her work on the island fox microbiome and its importance for fox health and immunity.

Dr. Allie explains that Catalina Island biologists "have been collecting swabs since 2017, so we are building a really nice longitudinal dataset. 2020–2021 samples will help that dataset grow. This will allow us to look at changes in fox microbiomes through time and (once we have enough repeat individuals sampled) see how treatment or past history of mite infection alters microbiomes in the short- and long-term."

If you missed the virtual event you can watch the video here.

More on the connection between microbiome and fox health on Catalina Island.

Not only were the CIC biologists taking these samples to enrich the microbiome data set, they were also putting radio collars, funded by you, on island foxes.

Friends of the Island Fox Wants to Give Back to You

 It's Giving Back Wednesday!

Thank you for your support of island fox conservation.

If you missed FIF's first virtual program, you can now watch a video recording. 

"Date with a Fox" Nov. 20, 2021: Dr. Alexandra DeCandia provides an update on her island fox microbiome research, supported by your donations, and island biologist Lara Brenner outlines a new effort to protect island foxes from introduced species on Santa Cruz Island.

 

We hope you'll share this with your friends.

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