The Catalina Island Fox is an endemic species to Catalina, meaning it is only found here. Living on an island for many years have caused the Catalina Island Fox to become 25% smaller than its mainland relative, the Grey Fox. This is a common microevolution that happens to animals living on islands, and is explained by a scientific principle called “Foster’s Rule”. Foster’s Rule (or the Island Rule) states that animals grow larger or smaller over generations depending on the resources available to them. Therefore, because there is a limited amount of lizards, berries, mice, and birds for the foxes to eat, they have dwarfed in size over the years to adapt and endure. The smaller foxes need less food to survive, and as a result they are the ones to pass on their genes to the next generation.
Though the foxes adapted to live on an island, they almost went extinct when an outbreak of Canine Distemper Virus nearly infected the entire population. In the late 1990’s, around 1,300 foxes roamed Catalina Island, however in 1999 a census showed that only 100 foxes remained. This staggering drop in the population was caused by the spread of a highly contagious virus called canine distemper virus. Quickly, the Fox Recovery Program was established by the Catalina Island Conservancy and the Institute for Wildlife Studies to aid in the revival of this beloved species. The plan combined vaccination, relocation, and captive breeding in order to let the foxes establish themselves again. The recovery program has been so successful, it has been proposed that the Catalina Island Fox be removed from the endangered species list. With a population over 1,700 in 2015, the fox appears to have made a tremendous recovery!
The Catalina Island fox population has made a journey from being healthy and established, to critically endangered, and back again. Their dramatic recovery shows what can happen when we, as humans, are aware of the impact we have on our earth, and are willing to step in to make things right.
