Wednesday, September 06, 2017

Tracking An Island Fox

Welcome guest writer Mike Watling. As a certified wildlife tracker and member of Ventura County Wildlife Trackers, Mike shares his expertise in identifying island fox tracks.

Visiting Santa Cruz Island this past winter, I was more excited than usual as it had rained a few days prior to the trip. The miracle of mud, following a rain, provides an excellent medium for studying the tracks left behind by animals. As a naturalist and wildlife tracker, I was looking forward to spending my day carefully observing the minute details of the delicate tracks of the Channel Island fox.

The island fox and its mainland cousin the gray fox are the only fox species capable of climbing trees. The island fox is the island's largest mammal and main predator; the top dog if you will.

Unlike the gray fox, which is primarily a nocturnal hunter, the island fox is active both day and night and can be readily observed foraging for lizards, insects, and fruit that comprise a large portion of its diet. To help conserve energy, foxes will often travel on the roads and trails found throughout the Channel Islands, leaving behind tiny tracks for the observant naturalist to find. 

Like all species in the Canidae family, the fox places its feet on the ground in a manner known as digitigrade. To put it simply, while they are moving, their body weight is being supported by the digits (toes) rather than the entire foot structure. In contrast, humans and bears are plantigrade, meaning the body weight while in moition is being supported by the entire sole of the foot. This characteristic is evident in the tracks left behind.

Consistent with all canids, the island fox has five toes on each forefoot. Toe one, the dew claw, is greatly reduced and located above the carpal pad on the inner leg. Only four toes typically appear in a track. The metacarpal pads, or palm,are fused together to form a larger rounded, yet triangular pad. The space between the toes and the pad, known as the negative space, forms an “H”.

The hind feet have four toes, and like the front, the pads are fused to form a narrow heel pad, which only partially registers in a track.  The negative space forms an “X”.
Island fox tracks are small, mostly symmetrical, approximately 1 to an 1 1/4 inches long by 13/16 of an inch wide, with the front track larger than the hind. The two inner toes tend to be close together and are often angled inward towards each other. Often the fur surrounding the foot will leave a visible impression in the track as well. The claws of the island fox are semi-retractable and slightly curved, and may not register. Even in mud, the claws appear very fine if at all. 

Island foxes generally move throughout their territory in a slight under-step trot. Having the shortest leg-to-body ratio of all the wild canines, the resulting track pattern is such that the front toes are visible ahead of a complete hind track.

While hiking the Channel Islands, take time to look closely on the side of the trail where you’ll likely encounter the tracks of the island fox, as well as other island inhabitants.  Quietly observe the entire area; look around for other pieces of evidence and you may be able to determine what the animal was doing.  Give pause, and for that moment, walk with the Island Fox. - Mike Watling