How are wild island foxes handled during annual health checks?
What data determines a healthy island fox?
What measures are taken to safeguard island fox health into the future?
How do island foxes contribute to ongoing research investigating their health, diet, and relationship to island ecology?
In this online Zoom program, FIF Board member and wildlife veterinarian Jessica Sanchez will take us through the steps of an island fox health check. She'll detail why each step is important and give the inside scoop on what a day performing health checks is really like.
Make a reservation and hold your spot for this fun and informative insider's view of island fox conservation.
Look who received a GPS tracking collar that you helped fund!
This young female island fox lives at the tip top of Santa Rosa Island in Channel Islands National Park. The GPS collar she's wearing was refurbished with donations to Friends of the Island Fox. The movements of this fox, documented by her collar, will help tell the story of her life: Where and how large is her territory? What resources can she access? Combined with dietary info, it will reveal how she is interacting with the island ecosystem.
VHF Collars - The Original
As island fox populations recovered from near extinction on four islands, individuals released back into the wild were collared with VHF radio-tracking collars to monitor their survival. (video of Senior Biologist for Channel Islands Park tells the story of island fox collapse of 1998–2000) VHF collars provide the location of an individual island fox at a specific moment. Biologists in the field are able to use hand-held antennae to triangulate the island fox's location. If a radio-collared island fox stops moving for 6–8 hours, the collar has a sensor that changes the signal from a "live-animal" beep to a possible "mortality" beep. This allows the quick retrieval of island fox bodies so the cause of death can be determined and steps can be taken to protect the island's entire island fox population.
Initially, GPS tracking collars were too large for female island foxes to wear. Today, modern GPS and battery technology provides for a smaller collar with less weight that can be worn by both male and female island foxes. GPS vs VHF collars
GPS collars document an individual island fox's location several times a day for months to a year. This data can now be downloaded remotely to allow researchers to track movement patterns, territory size, and overlap with other collared individuals without having much of an impact on wild island fox behavior. These collars include VHF capabilities and sometimes have additional abilities, like accelerometers that document movement patterns over 24 hours.
A new GPS collar for an island fox can cost $2400. GPS collars used in prior research projects for island foxes and San Joaquin kit foxes can be refurbished at a much reduced cost.
Digipeater Collars - New Technology and New Strategy
Digipeater collars include VHF capabilities, but they interact with a series of antennae stations. An island fox within signal view of the antennae is automatically check-in and reported as alive and well. Digipeater collars don't record precise movement like GPS collars, but they monitor island fox survival while reducing staffing hours in the field. More on digipeater collars and system
Sustainable monitoring of island fox survival requires reducing costs. FIF is assisting with the transition to monitoring island foxes on Santa Cruz Island with the Digipeater system.
No matter the type of tracking collar, protecting island foxes requires monitoring! Tracking collars provide the best opportunity to monitor island foxes while they live their wild lives.
Friends of the Island Fox happily announces that the 2025 Research Grant was awarded to Kimberly Schoenberger to expand her investigation of connections between island fox genetics and health: Transcriptomics of the Channel Island Fox (Urocyon littoralis) through RNA-seq.
Schoenberger is a Ph.D. candidate at the University of Southern California and works with the Natural History Museum of Los Angeles County. This second year of grant support will fund RNA genetic sequencing of an additional 40 foxes from across all six Channel Islands.
The initial 48 island foxes were all adults who had never been vaccinated. (First year of study) This second group includes juveniles and adults that had been previously vaccinated.
Health checks have revealed that San Nicolas Island foxes have similar ear mite infestation to Catalina Island foxes, but the foxes on San Nic do not develop microbial monocultures or cancerous tumors in their ears. Genetically influenced immune-system response may offer insight into why some island populations face health threats that others do not. Similar ear mite infestation with reduced microbial diversity has been found on San Clemente Island and the population there has faced survival declines in the last three years. (More on microbiome and connection to cancer in Catalina Island fox).
Examination of an island fox's ear canal with an otoscope
Schoenberger's RNA research may also provide noninvasive ways to detect dangerous amounts of internal parasites in island foxes. Examination of immune transcriptomes in dogs has shown that increases in specific interleukins signal the presence of intestinal worms. Currently island foxes are challenged by intestinal parasites, especially spirocerca on San Nicolas Island, anancanthocephalin on San Miguel Island, and possibly a new parasite on Santa Rosa Island.
Researchers like Kimberly Schoenberger are vital to healthy island fox populations. Insight from her work will help inform land managers and protect island foxes into the future.
Your donations make FIF's support for research possible.
