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.
In 2026, FIF's goal is to raise funds to refurbish 15 VHF radio collars for San Miguel Island. Cost to refurbish a VHF collar: $220
GPS Collars - More Info/Bigger Price
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.
In 2026, FIF's goal is to raise funds to refurbish 12 GPS tracking collars for Santa Rosa Island. Cost to refurbish a GPS collar: $500
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| Island fox with new Digipeater collar in 2025 |
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.
FIF has already raised funds for 15 new Digipeater collars in 2026. Now our goal is to raise funds for 3 additional antennae stations ($2000 each).
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.
