Showing posts with label golden eagle predation. Show all posts
Showing posts with label golden eagle predation. Show all posts

Tuesday, June 22, 2010

12th Annual Meeting of the Island Fox Recovery Group

Last week biologists and land managers from across the Channel Islands came together to report on the current status of California's endangered island fox.


The news in 2010 is very positive. Conservation efforts are paying off in increased population numbers for all four of the endangered subspecies–San Miguel, Santa Rosa, Santa Cruz and Santa Catalina Islands. But even as there was discussion on the criteria needed to support a possible delisting from endangered status, the importance of monitoring these vulnerable populations was brought home.

In the early months of this year, 11 island foxes on Santa Rosa were killed by an unnatural predator, a golden eagle. A juvenile golden eagle was spotted on several occasions, but to date it has not been caught. The deaths of the endangered animals came to light because of individual island foxes that were radio collared and monitored.

Across the islands radio collars enable biologists to quickly locate a fox that has died. When the animal doesn't move at all for six hours the radio collar changes it signal to a "mortality" pattern. This timely knowledge enables the biologists to immediately find the carcass and begin to determine the cause of death. The sooner the cause of death is understood, the quicker steps can be taken to protect other island foxes.

Radio tracking collars play a vital role in monitoring island foxes and have helped these tiny animals to make an unprecedented recovery for an endangered mammal species. This is why Friends of the Island Fox has worked to raise funds to place radio collars on individual island foxes. (See Radio Collars)

As we distill down our notes from the Annual Conference and verify our information with the island fox biologists, we will be posting an update for each of the 6 subspecies of island foxes.

While there are still challenges ahead for endangered island foxes, population numbers are up and community awareness is growing. Friends of the Island Fox thanks all of you who have played a role in raising funds, educating the public, and working on island fox conservation. You have played an important role in bringing the island fox back from the brink of extinction.

Saturday, November 29, 2008

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

Wednesday, January 17, 2007

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: