Friends of the Island Fox Friends of the Island Fox, Inc and Eclipse-1 Media

Friends of the Island Fox is currently taking applications through June 30 for the FIF 2024 Research GrantDownload Application From the complex relationship between island foxes and island spotted skunks, to diet, microbiome impacts on health, and changing territory sizes, research projects are revealing the complexities of the Channel Island ecosystem and the role of island foxes in island ecology. In 2024, Friends of the Island Fox is offering up to $7,000 in support to research projects benefiting greater understanding of the island fox and the Channel Island ecosystem.   Last year's grant recipients are using wildlife cameras to quantify island spotted skunk populations and investigating the impact of individual island fox behavior on the island ecosystem. It's Science, for Fox Sake! And we encourage all applicants to apply.  2023 grant recipient, D. Thomaier Past Research Grant Recipients and Projects Grant Recipients are asked to provide public updates on their work - "Date with a Fox" programs, hear from the researchers Published science on island foxes and island spotted skunks   Your Donations Help Fund this Important Science!

Juliann Schamel has been researching island fox diet using stable isotopes in whisker samples since 2018. Friends of the Island Fox has supported the processing of whisker samples through several Research Grants. In November of 2023, Schamel presented the following poster of her latest work at the California Islands Symposium. Using Stable Isotopes to Assess a Decade of Dietary Resource Use in Two Sympatric Island Endemics: The Island Fox and the Island Spotted Skunk (link to complete poster) Island foxes and island spotted skunks live together on two islands, Santa Rosa and Santa Cruz. When island fox numbers crashed due to predation by golden eagles, island spotted skunk numbers appeared to increase dramatically. In 2011, on Santa Rosa Island, there were still fewer than 90 island foxes in the wild. During annual health checks, whisker samples were collected from both island foxes and island spotted skunks in a northern area of the island and stored for later analysis of what food resources each species was using. In 2011, island spotted skunks out numbered island foxes in the wild. Stable isotope analysis shows that the skunks and foxes were using different resources.  J. Schamel, 2023 poster  Carbon and nitrogen isotopes travel up the food chain leaving a specific isotope signature for plant and animal resources. Literally, you are what you eat and isotopes from a mammal's diet are laid down chronologically in hair or fur. A single island fox whisker can provide 5–6 months of weekly diet data. On the graph above, native terrestrial plant foods, like manzanita berries, are high in Carbon and low in Nitrogen. A deer mouse is the accumulation of its own, mostly plant diet; it has a mid-range Carbon and Nitrogen signature. In the graph above, the blue data points represent island fox diet and the orange data points represent island spotted skunk diet.  In 2011, when island fox numbers in the wild were low, their diet tended to be higher on the food chain or trophic level: deer mice, birds and reptiles. The data suggested separate diet niches for island foxes and island spotted skunks. The skunks were eating primarily, lower level prey, like insects, and some plant foods. J. Schamel, 2023 poster In 2014, continuing drought influenced wildlife survival; island fox and island spotted skunks were nearly even in number on Santa Rosa Island. Island foxes expanded their diet, including marine resources, and island spotted skunks preyed more on deer mice and higher level prey. The two predators began competing for resources.J. Schamel, 2023 poster By 2018, the island fox population had recovered, but island spotted skunks appeared to decline in number. (Counting island spotted skunks) As island fox density increased across the island, they dramatically broadened their diet–from native fruit through a range of prey species. The spotted skunks maintained a more narrow diet, but they were now in constant competition with island foxes. What will this mean for the two species? Schamel's work also revealed that individual island foxes are becoming specialized in their diet. J. Schamel, 2023 poster   In the graphic above, each circle of data points represents an individual island fox and its diet. Some individuals appear to be specializing in fruit and insects, while others are eating predominately terrestrial prey. How is island fox diet continuing to change? Save the date of April 30th at 6:30 pm PT Juliann Schamel will talk about her work on FIF's "Date with a Fox" webinarsign-up for FIF's e-newsletter to receive an invitation Measuring out a whisker sample Whisker samples continue to be collected for both species.  designed by island biologist, Stacy Baker When you purchase an island spotted skunk pin, you send a sample of island spotted skunk whisker to the mass spectrometer to reveal stable isotopes.

  Are island spotted skunks genetically different enough from mainland spotted skunks to warrant species status? FIF 2022 Research Grant recipient Julia Owen is probing the island spotted skunk genome.   Are island foxes crossing into the territory of other island foxes to access beach foods on Santa Rosa Island? FIF 2021 Research Grant recipient Katie Elder and recipient Juliann Schamel continue to investigate island fox territory size and diet.  Are you investigating island foxes, prey species, Channel Island ecosystem dynamics, public education and attitudes toward island fox conservation, or any topic relating to island fox survival and a healthy island ecosystem? Apply for FIF's 2023 Island Fox Research GrantDownload Application Grants will be considered for up to $7,000 Application Deadline August 28