Tuesday, November 15, 2011

Island Fox Population Update

courtesy of Anita Machlis
Every year biologists count island foxes across the California Channel Islands in the late summer and early fall. Island foxes are captured in safe traps so they can be given health checks, fitted with radio collars and given vaccinations. When the biologist from the six different islands meet for the annual Island Fox Conference in June, they share their official population numbers and discuss the successes and challenges from each island.

The official population estimates from 2010 are:
  • San Miguel Island - 516
  • Santa Rosa Island - 292
  • Santa Cruz Island - 1302
  • Santa Catalina Island - 1008
  • San Nicolas Island - ~500
  • San Clemente Island - 1127

The numbers show that island fox recovery has been very robust on San Miguel, Santa Cruz and Santa Catalina Islands. The island foxes on Santa Rosa Island are recovering, but at a much slower rate. Each island fox population has its own challenges. For the current status of island foxes by island Download - Island Fox Update 2011 pdf

Stay tuned for updates on 2011 population numbers as they come in from the autumn field counts. 

Monday, November 07, 2011

A Radio Collar for Tani, the Island Fox!

photo courtesy of Kevin Schafer
Across the Channel Islands young island foxes are striking out on their own. They have spent the summer playing with their siblings and growing up. Their parents have taught them to hunt and find native fruit. Island fox food. Now, it is time for them to search out their own territory.

Tani, the young island fox that we have been following on Twitter, has left her parents and faced some challenges. Tani. A few days ago she tangled with another adult island fox female and was injured. Island foxes depend on the resources in their territory and they will protect their territory from other island foxes. Tani was lucky to only be injured on her ear, but the infection she suffered left her weak and vulnerable. Fortunately, on the Channel Islands biologists in the field are able to provide some medical care to wild island foxes. (Channel Islands National Park, Santa Catalina Island and the U.S. Navy islands)

When Tani received medical treatment she also was fitted with a radio collar to track her movements. The radio collar will provide information on how far she travels from her parents home range and enable biologists to understand where a young fox establishes its own territory. 

Across the islands young island foxes face challenges surviving without their parents. In the past two months several young island foxes have been hit by cars on Santa Catalina Island. Territory along roads can be attractive, but inexperienced youngsters don't know how to avoid cars. Support Watch for Foxes Signs.

This autumn Friends of the Island Fox funded our 72nd radio collar to track island foxes on the Channel Islands. Radio collars provide information on island fox movements and also alert biologists when an island fox has died. If the animal stops moving for a 6-8 hours, the collar gives off a special mortality signal. With the aid of the radio collar, biologists can locate the island fox's body and determine if the animals death marks a potential threat to other island foxes. Response to introduced disease and unexpected predation by golden eagles can happen rapidly when biologists have specific information from animals in the field. Radio collars on island foxes have helped the endangered populations on San Miguel, Santa Rosa, Santa Cruz and Santa Catalina Islands to make unprecedented recoveries.

photo courtesy of Kevin Pease
Tani is wearing her new radio collar and hopefully it will help biologists track her recovery and her activities as she becomes an adult island fox and establishes her own territory.

Follow Tani on Facebook and on Twitter.