Foxes do not exist on islands, with the exception of a fox that occurs on some of the Channel Islands. This archipelago is located off the coast of California in the United States. The archipelago is quite large in area, about 900 square kilometers. It has a pleasant climate, but not many people live there. Almost all people live on the island of Santa Catalina. There are almost as many different foxes as there are islands in the Channel Islands. Although they can reproduce with each other, there are genetic and observable differences between the foxes. The island fox is not afraid of people and is easy to domesticate. The island fox is threatened by all kinds of causes: the golden eagle, the disappearance of food and diseases of dogs.
- Taxonomic Classification
- General Channel Islands
- Origin island fox Channel Islands
- Types of island foxes
- Description island fox
- Features island fox
- Length, size, weight of the island fox
- Appearance island fox
- Appearance fox San Clemente and San Nicolas
- Communication
- Reproduction island fox
- Lifestyle island fox
- Food
- Threat from the island fox
- The golden eagle
- Diseases
- Food shortage
- Marine
Taxonomic Classification
- Rich: Animalia;
- Strain: Chordata;
- Class: Mammalia;
- Order: Carnivora;
- Family: Canidae;
- Genus: Urocyon;
- Species: Urocyon littoralis.
General Channel Islands
As such, there are no foxes on islands, with the exception of a fox that occurs on some of the islands of the Channel Islands. The Channel Islands are an archipelago off the coast of California. It is an archipelago of eight islands in total, five of which are part of the national park: Channel Islands National Park. The islands that belong to the national park are: San Miguel, Santa Rosa, Santa Cruz, Anacapa, and Santa Barbara. The entire archipelago is about 900 square kilometers in size.
The islands are divided into a northern and a southern part. In 2019, a total of about 4,000 people live on the islands, most of which, about 3,700, live on Santa Catalina. Two of the islands, San Clemente and San Miquel, are used by the United States Navy.
Anacapa Island / Source: Constantine, Wikimedia Commons (CC BY-SA-3.0)
Northern Islands
- San Miquel;
- Santa Rosa;
- Santa Cruz;
- Anacapa.
Southern Islands
- Santa Barbara;
- San Nicolas;
- Santa Catalina;
- San Clemente.
Santa Rosea / Source: Exoplanetaryscience, Wikimedia Commons (CC0)
Origin island fox Channel Islands
It is likely that the gray fox arrived in the northern islands of the Channel Islands about 13,000 years ago. Foxes were the first to appear on three of the northern islands. The sea level was much lower at the time, making the four islands of the north one large island, which was called Santa Rosea. The distance between the large northern island and the main land was also not that great. The fox has, as it were, walked or been driven to the island. The fox on the southern islands was probably brought there 3,000 years ago by Native Americans who used the fox as a pet or hunting dog.
Types of island foxes
It occurs on six of the eight islands. The island fox is not found on Anacapa because that island has no fresh water source and Santa Barbara is too small to provide enough food for the island fox. Each island has its own kind. Although the foxes can reproduce with each other, they are genetically different and there are other visible differences as well. So there are six different island foxes:
- Urocyon littoralis littoralis from the island of San Miguel;
- Urocyon littoralis santarosae from Santa Rosa Island;
- Urocyon littoralis santacruzae from Santa Cruz Island;
- Urocyon littoralis dickeyi from the island of San Nicolas;
- Urocyon littoralis catalinae from Santa Catalina Island;
- Urocyon littoralis clementae from the island of San Clemente.
Source: Pacific Southwest Region USFWS, Wikimedia Commons (CC BY-2.0)
Description island fox
The fox is the smallest fox in the United States. The fox is descended from the gray fox but is a lot smaller and that’s caused by something called island dwarfism. If animals end up on an island, or in an ecosystem where the population and growth possibilities are limited, the phenomenon occurs that an animal species becomes smaller. Another disadvantage of living in a small gated community isolated from your peers is that this fox is vulnerable to all kinds of diseases and parasites that can come from the mainland to the islands. Diseases therefore threaten the island fox with extinction.
Features island fox
Island foxes are not shy at all, but even easy to domesticate. They were kept by the islanders as pets and probably also as a way to control mice and rats.
Length, size, weight of the island fox
The length without tail is about 50 cm, the height of a red fox is about 35 to 40 cm, but that of the island fox is only 12 to 15 cm high. The tail is about 10 to 30 cm long.
It weighs about one to three kilos. The largest island fox is the one on the island of Santa Catalina. The smallest lives in Santa Cruz. A male island fox is always larger than the female.
Appearance island fox
An island fox has a gray head with a black spot on both sides of the muzzle, the rest of the fur is gray with red colored stripes on the sides. It has a white band and the bottom of its mouth is also white. There is a black stripe across its tail. The coat is darker than that of its gray mainland nephew. The island fox sheds once a year in the months of August to November. Before the cub sheds it is a wool ball and the coat is darker than the adult.
Opunita cactus / Source: Stan Shebs, Wikimedia Commons (CC BY-SA-3.0)
Appearance fox San Clemente and San Nicolas
The foxes of San Clemente and San Nicolas may have their gray-black coat suddenly sandy brown to deep brown after molting. It is not entirely certain whether discoloration is due to molting or whether the color difference is caused by an indigenous plant, the Opuntia cactus or the prickly pear. The juices of this plant contain a natural colorant and the discoloration could be caused by the prickles of the cactus getting stuck in the island fox’s fur.
Communication
The island fox communicates through sounds and body language such as staring and by holding its ears in certain positions. This also shows whether the fox is dominant or submissive. He makes barking and growling noises. Another way of communicating is to demarcate his area with urine and feces.
Reproduction island fox
Like the red fox, the island fox is basically monogamous. The fox is fertile in the months of January to March. The couples are inseparable during that period. The female is pregnant for 50 to 63 days. The female retreats to a den to give birth. An island fox gives birth to one to five cubs per throw. The average per litter is two or three young. They are born in the spring and leave the burrow in the summer. They are sexually mature at ten months. The island foxes live for four to six years in the wild. In captivity, the fox will live to be eight years old.
Lifestyle island fox
The island fox prefers to live in sheltered areas with fruit-bearing shrubs. The island fox is found in all areas on the islands: forest, meadows, hills and so on. There are no more than a thousand foxes per island.
Food
Like the gray fox, the island fox climbs trees. It eats fruits, insects, lizards, crabs, eggs and small mammals. The island fox only hunts in the evening, in the early morning or at dusk. In summer the fox is more active than in winter.
Threat from the island fox
The island fox is an endangered species, except for those residing on San Clemente and San Nicolas. There are also four dangers that threaten the fox with extinction:
- golden eagle;
- diseases;
- food shortage;
- navy.
Golden eagle / Source: J. Glover – Atlanta, Wikimedia Commons (CC BY-SA-2.0)
The golden eagle
Until recently, the golden eagle was not found in the Channel Islands at all. At one point it was discovered that the number of foxes had been severely reduced from thousands to just a few hundred, dozens on some islands. The golden eagle turned out to be the cause. The bald eagle used to be found on the islands, so the golden eagle probably stayed away. The bald eagle eats fish, small birds and rodents but left the fox alone. Wild boars were also found on the islands and the golden eagle probably came to see them. Then they killed all wild boars on the island of Santa Cruz in the hope that the golden eagle would disappear, but then it turned out that the eagle was mainly focusing on the island fox. Probably the only thing that will help protect the foxes from the golden eagle is to get the golden eagle away from the islands. The fox is no match for the golden eagle which is four times the size of the island fox.
Diseases
The island fox is particularly vulnerable to all kinds of diseases because the isolation on the islands has prevented it from building up resistance against those diseases. Dog diseases are especially dangerous for the fox. In the year 1998 the population on Santa Catalina was reduced from 1300 to 103 by the outbreak of a distemper. The disease is likely to have come from one of the pets or from a raccoon that happened to be on the islands. In 2019, pets are no longer allowed to enter the National Park and the foxes are vaccinated. There are now more foxes on Santa Catalina than in the time before the disease struck.
Food shortage
Another reason for the drastic population decline is that the available food for the island fox has declined. That’s because other animals have come to the island such as feral cats, pigs, sheep, goats and the American bison.
Marine
To protect a native bird, the Great Gray Shrike, from San Clemente Island, the U.S. Navy actively killed the fox until the year 2000. After 1990, the Navy used other methods, such as catching the fox during the bird’s breeding season and releasing the fox afterwards. They also have a fence with electricity around the bird’s habitat and the foxes have straps to distribute electric shocks. Now the bird is no longer threatened and the fox is left alone.
