Tuesday, January 28, 2014

Which Island Foxes Wear Radio Collars?

island fox with radio tracking collar; courtesy CIC
Island fox populations are returning to normal levels across the six California Channel Islands where this rare species lives. With hundreds of island foxes on each island, the number of radio-collared animals is limited to a representative group. Typically 40-60 individual animals wear radio-tracking collars on each island.

 Which island foxes receive radio tracking collars?

Island foxes that wear radio-tracking collars are typically younger–ages 1-4 years old. Island foxes can live 8-10 years in the wild, with rare individuals living to age 12 years. Younger animals are more likely to move across the islands as they try to find a mate and establish their territory. (Female that traveled across Catalina's isthmus

While some radio-collared island foxes are individuals with specific survival challenges (Burnie Boots and three-legged island fox), most collared island foxes act as disease and predator sentinels. If something happens to these foxes their demise is quickly brought to the biologists' attention because of the radio collar. When an island fox stops moving, even breathing, for over six-eight hours the collar signals a specific mortality signal. Using the signal, biologists can locate the island fox's body, discover the cause of death and take action. (Listen to radio signals on our Audio/Video page)

“Being able to identify the threats greatly improves our ability to understand and protect this unique species,” says Julie King, director of conservation and wildlife management for the Catalina Island Conservancy. Once the carcass is collected it is sent to the California Animal Health and Food Safety Laboratory to ascertain the exact cause of death.

Both male and female island foxes can be sentinels. These individuals are not vaccinated against the two most threatening diseases to island foxes–rabies and canine distemper. (FIF vaccination funding) 

courtesy of Jason Bean
Reading information from the radio-collars varies across the islands. On flat-terrain islands radio receiver towers pick up the signals of island foxes in their area and relay the information to a computer terminal. Mountainous terrain is more challenging; on some islands radio-collar signals are picked up from the air by small aircraft, weekly or biweekly. On other islands, biologists with hand-held antennae and a receiver locate island foxes from vehicles or on foot.

In 2014 FIF has the goal to fund our 100th radio collar. With your help we will reach that goal.