CATALINA ISLAND FOX FACTS HOW BIG IS THE FOX?
The Catalina Island fox is about 25% smaller than its mainland relative, the gray fox, and is Catalina’s largest native land predator. Although it is often referred to as “the size of a house cat,” an adult Island fox generally weighs 4–6 pounds, while house cats average 8–10 pounds with some breeds weighing as much as 18 pounds.
WHAT DOES THE FOX
EAT?
An omnivore, the Catalina Island fox’s diet includes mice, lizards, birds, berries, insects and cactus fruit. Taking advantage of many food resources enhances the foxes’ chances for survival on the Island. The foxes climb trees in search of food. But they’re hard to spot on the Island. They may be active during daylight, but most of their foraging for food is done at dawn and dusk.
HOW DO THEY
REPRODUCE? Foxes generally form monogamous pairs. They breed
once a year, usually in early February through early March. Pups are born from midMarch through May. Litter sizes may range from 1–5, but 1–2 pups are more common
PHOTO: JULIE KING
in the wild. Unlike most other species of foxes, Island foxes do not use formal dens. They generally just find refuge under thick brush or in a rock pile. Pups are born helpless, and both parents play a role in raising the young. Pups emerge from their den sites after about a month. They remain with their parents for approximately 6 months before dispersing in late fall to find their own territories and mates.
125 Clarissa Ave., Avalon, CA 9070
310-510-2595
CatalinaConservancy.org
HOW DID THE FOX GET HERE?
PHOTO: JACK BALDELLI
Previous genetic research suggested that foxes first inhabited the northern Channel Islands more than 16,000 years ago, a few thousand years prior to humans, who arrived around 13,000 years ago. But archaeological and paleontological data indicated a much more recent introduction of approximately 7,000 years ago. Considering both timelines, scientists generally answered this question by stating that foxes first arrived on the northern Channel Islands by rafting on debris or were introduced by Native Americans. Both theories have support. Lower sea levels at the time resulted in the northern Channel Islands being a single immense island much closer to the mainland than the islands are currently. There is confirmation that several other species that have inhabited islands in other areas did so by rafting on debris. The connection between Island foxes and Native Americans is also very well documented, and there is no question that the foxes were introduced to the southern Channel Islands, including Catalina, by Native Americans. So which is it? A genetic study led by Smithsonian predoctoral fellow, Courtney Hofman, provides some more evidence to support the hypothesis that humans were involved with the first introduction of foxes to any of the Channel Islands. Instead of using a fraction of mitochondrial DNA, as was done in prior genetic research, Hofman was able to analyze entire mitochondrial genomes. Her results suggest that foxes did not arrive on the northern Channel Islands until 7,100–9,200 years ago, much closer to the time that humans first inhabited the islands. A confounding issue remains, however. The earliest fossil records for Island foxes reflect an already diminutive species, suggesting that the foxes had already evolved on the Island for thousands of years prior to human colonization. Perhaps new advancements in genetic research or new archeological discoveries will once and for all solve this mystery. But for now, both possibilities must be considered.
HOW DOES THE FOXES'
RECOVERY HELP PROTECT THE ISLAND? Protecting the Catalina Island fox is crucial to the health of the Island’s ecosystem because it is considered a “keystone species,” which has a disproportionately large effect on its environment in relation to its actual numbers. Island foxes are “opportunistic omnivores,” meaning that they feed on a wide variety of food items and focus primarily on what is most abundant or available. Through this approach, foxes are able to prevent certain animals, such as mice, from becoming overly abundant on the Island. Foxes also support the spread and germination of seeds when plants are actively producing fruit. In the same manner, foxes do not exhaust a food resource entirely but rather shift to whatever item is easily attainable. In this manner, they support the balance of the ecological community. From the management perspective, the Catalina Island fox is also categorized as an “umbrella species.” This means that the successful conservation of the Island fox and its habitat indirectly protects the many other species present in the community.
125 Clarissa Ave., Avalon, CA 9070
310-510-2595
CatalinaConservancy.org