Tuesday, July 07, 2015

Observing Channel Island Fox Behavior on Santa Cruz Island

Santa Cruz Island, Channel Islands National Park
Participants in the Friends of the Island Fox trip to Santa Cruz Island on June 20th had a beautiful day and an opportunity to observe behavior between individual wild Channel Island foxes. Fifteen years ago, when this subspecies of Channel Island fox was facing extinction, such an opportunity was unthinkable.

The island foxes on Santa Cruz Island have made a strong recovery. A baby boom of foxes occurred on Santa Cruz between the fall count in 2007 and 2009. The population jumped from 350 to 1,200. Adult survivorship has been very high, which means we are seeing an increasing number of island foxes between the ages of 5 and 8 years old. These are mature individuals. Island foxes are believed to be in their prime between 2-5 years of age and are estimated to live 8-10 years in the wild.

This trip two elderly animals were noticeable by their broken-down ears and minor injuries to legs and tails. These injuries were most likely inflicted by younger adult island foxes protecting territory. The campground offers an area where infirm animals can potentially find resources, while having some protection from other foxes. 

We observed this older island fox lying down on the ground between campsites where people were active at tables. His coloring camouflaged him well in the dappled shade.

When some campers left their site, a healthy adult island fox checked out their table area. We watched as the slightly larger, but older animal, approached. We didn’t know what to expect.

Submissive behavior of elderly island fox toward another adult.
However, when the older fox got within five feet of the table area, it lowered its head submissively to the younger animal. The younger fox did not chase the older animal or show aggression, yet it physically communicated to the older fox not to approach any closer. Without any direct contact, the older fox was sent off into the bushes.

photo courtesy of Daniel Mekonnen, 2015
We saw 8 - 10 adult island foxes (none were radio-collared individuals). 

We watched island foxes searching for food, retrieving figs, and eating them (Check out the video by Douglas Welch). (The fox jumps up into a shrub at ~2:48) A large percentage of the Santa Cruz Island fox’s diet is fruit.

We’ll have more on the status of the Santa Cruz Island fox in an upcoming Island-by-Island Update. At the Island Fox Conservation Working Group meeting, biologists from The Nature Conservancy reported that a female island fox, born during captive breeding on Santa Cruz, recently passed away at age 12. She is the oldest wild island fox scientifically documented on Santa Cruz Island. Biologists were able to accurately date her age and follow her life because of her ID microchip.

We also had a fantastic encounter with common dolphins on our boat ride home. Hundreds of these colorful dolphins were feeding and swimming right next to us. Look closely and you will see a youngster swimming beside its mother. We saw numerous young dolphins.  (Video of the common dolphins by Douglas Welch).

More photos of the Friends of the Island Fox Trip to Santa Cruz Island:
A special thank you to trip participants Eric Gotthelf, Douglas Welch, Michael Solomon and Daniel Mekonnen for their photos.