Island Fox Origins and the Truth Behind Eagle Diets

Are you looking for information on the origin of island foxes; how they evolved and their biology? Perhaps you’ve heard people question whether golden eagles were actually preying on island foxes. Answer your questions with information from the primary sources.

Friends of the Island Fox is honored to make information available from top researchers and biologists working with the island fox and the Channel Island ecosystem.


Paul W. Collins, Curator of Vertebrate Zoology at the Santa Barbara Museum of Natural History recently gave two presentations from his accumulated research at an Island Fox Workshop sponsored by the Santa Barbara Museum, Ty Warner Sea Center, Santa Barbara Zoo and Friends of the Island Fox. Both of these presentations are now available through links from the Friends of the Island Fox Educational Research Library.

• Origin, Evolution and Biology of the Island Fox - looks at genetic, morphological, and archeological data regarding island fox origins and the basics of island fox biology, size, behavior, reproduction and diet

• Diet of Bald and Golden Eagles on the Channel Islands - looks at the role eagles played in the decline of island foxes on the Northern Channel Islands and compares the diet of bald and golden eagles on the islands by examining prey remains in nests.

These two slideshow presentations can be found in the Educational Research Library

Under: “Island Fox Fact Sheets & Current Research”

Under: “Links to Research Sources”

Friends of the Island Fox is endeavoring to create the Internet’s most current library of information regarding island foxes. If you are a researcher or biologist and would like us to link to or host your published work relating to the island fox or the Channel Island ecosystem, please contact the Friends of the Island Fox Webmaster at islandfoxnews@gmail.com

Island Fox Research Notes – Hilary Swarts

Hilary in the field on Santa Cruz Island with one of the oldest collared females, A3Y. (Photo by Jessica Sanchez)

“You can kind of see her collar ID colors: Pink, White, Pink, Pink. That's how we identify the foxes photographed by remote cameras. Annoyingly, it doesn't work all the time. This female just got her newly painted collar in mid October.” - Hilary

Research: Circadian temporal activity of the Santa Cruz Island Fox (Urocyon littoralis): A possible newfound anti-predator defense for a naïve, endangered species

Hilary Swarts, a PhD candidate at the University of California at Davis, is studying the behavioral response of the island fox to golden eagles, a predator to which foxes are not adapted. Her theory is that foxes, which are naturally active during the day (diurnal), have possibly changed their behavior in response to predation pressures from golden eagles. Eagles also hunt during the day, so foxes may be responding by being more active at night (nocturnal). Specifically, the research is investigating whether behavior patterns of foxes on Santa Cruz Island have changed in the period since the 1990’s when golden eagles colonized that island. If foxes have changed their behavior, this shift may be a selection- or learning-based response to predation by golden eagles, or it may be a response to reduced fox density.

Hilary’s research will examine several aspects of island fox ecology including reproductive success, changes in population abundance in response to different levels of predation, daytime activity levels in the absence of predation, and will compare measures of daytime activity to the risk of predation. The results from her research will contribute scientifically to the understanding of the effects of invasions on behavioral ecology, while also providing crucial information to resource managers on the risks of golden eagle predation to the Santa Cruz Island fox population.

Hilary Swarts , Ph.D. Candidate
Department of Wildlife, Fish, and Conservation Biology
University of California at Davis


FIF plans to fund future island fox research. You can help with your donation to Friends of the Island Fox, Inc. To donate use the PayPal or Network for Good buttons in the upper right corner.

For more on Santa Cruz Island and the island fox:

• Experiencing Santa Cruz Island
  
• Where Does the Island Fox Live
• What is an Island Fox
• What Do Island Foxes Eat?