Is That An Island Fox? Identifying North American Foxes

Fox species overlap in many parts of North America, which can make it difficult to distinguish one species from the next. In California alone, there are four fox species:

• island fox - seen in the wild only on the Channel Islands
  
• gray fox
• red fox
• kit fox

The last three occur only on the mainland. If you are fortunate to see a small to medium canid in the field, you should ask yourself a few questions to aid in identification:

fox silhouette

 

coyote silhouette

1. Is it a coyote or a fox? 

Coyotes now inhabit most of North America, but they are typically larger than foxes and appear more dog-like with a larger face. The coyote tail is also shorter for their body than a fox's. While most foxes have distinct color markings to aid in identification, coyotes do not.

If it is a fox: 

2. Start with the tip of the tail:

White tail tip: Probably a red fox. Even if the fur coloring is not red or cinnamon, a fox with a white-tipped tail is a red fox.  The image to the right shows a "silver fox," an almost black-colored fox with white-tipped guard hairs beside a red fox. Both show a white tail tip. 

The silver fox is a color phase of the red fox (Vulpes vulpes). Most foxes used in the fur trade are red foxes. They are bred for various colorations. (FIF's red fox pelts are used in education. The silver fox pelt was rescued from a 1940s coat and the wild red fox was a car strike victim in 2005.)

 

gray fox; ancestor of the island fox

Black tail tip:

With a black stripe all the way down the back - you are looking at a gray fox. (If you are on the Channel Islands, it's an island fox.)

island fox on Catalina Island

 

kit fox; courtesy of K. Schafer

 

Just a black tail tip: Consider your location.

The Gemini foxes, the kit fox and the swift fox, seldom overlap in range. If you are located in parts of New Mexico and adjacent parts of Texas, big ears will separate the kit fox from the swift fox. In general, understanding the habitat where you see the fox will provide a clue as to the species you're observing.

No, definitive tail tip coloration: Arctic fox

Arctic foxes are easy to identify by their white coat in winter or their compact body size with small rounded ears and no contrasting marks on the tail.

Use this downloadable Identifying the Foxes of North America chart to help you know your local foxes. 

In this series of posts, we only touched the basics for each of the species covered. A list of research used in writing this project can be found at the end of each post. These resources are a great starting point for more information about the foxes that may live in your area. In addition, reading the abstracts of research articles provides wonderful insights into the latest information regarding a particular species. While the thought of wading through heavy scientist language may make your head spin, the abstract's concise language will slow that spin, allowing you the opportunity to glean useful information to assist in the better understanding of the fox you're interested in. It will also help sort fox fact from fiction.

Thank you to FIF Board Members - Mike Watling and Lara Brenner for this series on North American Foxes.

Series installments:

How is the Island Fox Unique?

Red Fox: Life on the Edge

Gemini Foxes: Kit Fox and Swift Fox

Arctic Fox: Fox of the Tundra

The Island Fox's Origin - The Gray Fox

 

Gemini Foxes: The Kit Fox and Swift Fox

Santa Cruz Island fox

In the first installment of Foxes of North America we introduced you to the beautiful and intelligent red fox, a fox that prefers to live on the edge and is very different from the island fox.

Here we'll take a quick look at the kit and swift foxes. Don't be fooled by their general appearance–they are not island foxes.

According to J. David Henry in his book Foxes: Living on the Edge, "The kit fox and the swift fox are the Gemini foxes of North America," because they share many physiological and morphological similarities. Kit and swift foxes inhabit the arid regions of North America and are adapted to habitats with relatively open vegetation.

 

Kit Fox, photo courtesy of CA Fish & Wildlife

Kit Fox

Kit foxes are native to the desert and semi-arid shrublands and grasslands of the southwestern US, including parts of Oregon, Colorado, and northwestern Mexico. They are a small fox species with a slender appearance, 5 pounds on average. Their coat is grizzled to tawny gray with buffy highlights on the neck, sides and legs. Their face has a typical "foxy" appearance, except for their ears, which are much longer than those of any other North American canid. This adaptation may help them dissipate body heat in the desert and could help them hunt insects and mice. To protect their feet from the hot sands, kit foxes have considerable hair between the pads, forming a kind of "sand shoe." Kit foxes are often confused with gray foxes because their ranges overlap, but kit foxes can be distinguished by the lack of a black ridge running the length of the tail as well as by their large ears.

The scientific name is Vulpes macrotis, which translates to "big eared fox."

San Joaquin Kit Fox, photo courtesy Tory Westall, ESRP - CSU Stanislaus

Kit foxes are opportunistic foragers that rely heavily on rodents and insects for sustenance. Kangaroo rats, pocket mice, and ground squirrels are common rodent prey. Like island foxes, kit foxes also consume beetles and grasshoppers. Kit foxes are also known to consume rabbits, birds, reptiles, and a variety of non-insect invertebrates

A unique feature of both the kit fox and the swift fox is the continuous use of underground dens throughout the year. Other canid species, including the island fox, use underground dens only during pup season. The Gemini Foxes clump their dens in suitable habitat and use them to provide critical protection from predators and shelter from extreme temperatures in desert summers and northern winters.

The San Joaquin subspecies of kit fox (V. macrotis mutica), which is restricted to the San Joaquin Valley and adjacent valleys in California, is currently listed as endangered under the Endangered Species Act. The kit fox is also listed as endangered by the State of Colorado and as threatened by the State of Oregon. The most serious threats include habitat loss and declining habitat suitability due to invasion of non-native grasses.

Swift Fox, photo courtesy K. Schafer

Swift Fox

Swift foxes primarily occur in the short and mixed-grass prairies from New Mexico and Texas north to southern Canada. Similar in size and appearance to the kit fox, the swift fox is pale yellowish-red and grey, with a thick grey stripe down its back that extends to its black-tipped tail. Its underside is lighter in color, and it has black patches on either side of its muzzle. You can distinguish swift foxes from kit foxes by the swift fox's smaller and rounder ears. Also, the swift fox's tail is shorter in relation to its body size than that of the kit fox.

Their scientific name is Vulpes velox, which simply translates to "swift fox."

 

Swift Fox, photo courtesy Gordon Court

 

Swift foxes are resourceful foragers, with a varied diet that includes small mammals, such as prairie dogs, birds, insects, plants and carrion. To reduce risk of predation by coyotes, swift foxes avoid areas with high prey density, such as areas of high plant diversity. They prefer open habitat where visibility is greatest.

Once abundant throughout their range, swift fox populations began to decline in the late 1800s due to rodent and predator control programs and the plowing of prairie into cultivated crop fields. As a result, the species is currently recognized as a species of conservation concern over much of its range. In Canada, the swift fox was gone or extripated by the 1930s. However, in 1983, a privately run program began breeding swift foxes in captivity in the US so that they could eventually be reintroduced back into the wild in Canada. Experts from this captive breeding effort provided advice for the captive breeding of island foxes in the early 2000s. While swift foxes are still classified as endangered, the swift fox's return is one of the most successful species reintroduction stories in Canada, just as the island fox's recovery is hailed as a success in the US.

Coming up next is the Fox of the Tundra: Arctic Fox

Series installments:

How is the Island Fox Unique?

Red Fox: Life on the Edge

Arctic Fox: Fox of the Tundra

The Island Fox's Origin - The Gray Fox

For additional information on the San Joaquin Kit fox visit: https://www.facebook.com/groups/friendsofthesjkf

References:

Butler, Andrew R., Kristy L.S. Bly, Heather Harris, Robert M. Inman, Axel Moehrenschlager, Donelle Schwaim, and David S. Jachowski. May 22, 2020. "Home range size and resource us by swift foxes in northeastern Montana." Journal of Mammalogy, vol. 101, (3), pg 684–696. Accessed at: https://doi.org/10.1093/jmammal/gyaa030

Cyper, B.L. 2003. "Foxes (Vulpes species, Urocyon species and Alopex lagopus)." In Wild Mammals of North America: Biology, Management, and Conservation, 2nd edition by G. Feldhamer, B. Thompson, and J. Chapman (eds), pg 511–546. Baltimore: Johns Hopkins University Press.

Elbroch, M. and K. Rinehart. 2001. Behavior of North American Mammals. pg 94–100. Peterson Reference Guides.

Harris, Heather (ed). July 2020. Swift Fox Conservation Team Report for 2017–2018. Montana: Montana Fish, Wildlife & Parks Glasgow.

Henry, J. D. 1996. Living on the Edge, Foxes. Minocqua, WI: Northword Press. 

Kelly, Erica C., Brian L. Cypher, and David J. Gemano. 2019. "Temporal variation in foraging patterns of Desert Kit Foxes (Vulpes macrotis arsipus) in the Mojave Desert, California, USA." Journal of Arid Environments, vol 167, pg 1–7. ISSN 0140-1963.

Meaney, C.A., M. Reed-Eckert, and G.P. Beauvais. August 21, 2006. Kit Fox (Vulpes macrotis): a technical conservation assessment. USDA Forest Service, Rocky Mountain Region. Accessed at: http://www.fs.fed.us/r2/projects/scp/assessments/kitfox.pdf 

 

 

Not All Foxes Are The Same - Red Fox vs. Island Fox

Santa Cruz Island fox

Foxes are small- to medium-sized members of the dog family that are found throughout the world. In North America there are six species of fox: Red Fox, Gray Fox, Kit Fox, Swift Fox, Arctic Fox, and of course, the Island Fox. Foxes are the smallest of the North American wild canids, the others being wolves and coyotes. Foxes are very intelligent and adaptable. They occupy varying landscapes across the continent from the vast Arctic tundra to the desert scrub land of the American southwest. From the wind-swept prairies to the boreal forests, the foxes of North America have carved out a niche as specially adapted predators of small prey. 

In the first of a multi-part post on different foxes, we'll introduce you to the Red Fox.

 

European red fox

 

Life on the Edge: Red Fox

The red fox is the most widely distributed land carnivore on the planet, with a range covering more than 28 million square miles. By contrast, the San Miguel Island fox has a very small range: only 24 square miles. Red foxes occupy five of the seven continents, including Australia, where they were introduced by English settlers in the 1800's. Only South America and Antarctica are free from these adaptable animals.

The scientific name for the red fox is Vulpes vulpes, the "fox's fox," which is fitting since most people conjure up an image of the red fox when asked about foxes. (Island fox's scientific name.) The presence of red foxes all over the world has led to their appearance in pop culture and folklore as people are readily drawn to this beautiful and cunning creature. More than any other canid, the red fox has received positive representation in literature and film. Aesop's Fables contain numerous tales of foxes. Disney's The Fox and the Hound tells the story of two unlikely friends, a red fox named Tod and a dog named Copper. To indigenous tribes of North America, the fox is a spiritual animal with different meanings across cultures–from a clever trickster to being associated with intelligence and wisdom.

Tod fox from Disney's The Fox and the Hound

 

Red foxes are the largest of the North American fox species, with a long, bushy tail, a narrow pointed muzzle, and thick soft fur. Their legs are slender with black fur covering the feet, nose, and the back of their erect, pointed ears. The coat of the upper body, head, and tail are bright red to yellowish-red. The tip of the tail is white. Adults are approximately 36–42 inches in total length and their tail accounts for slightly more than one-third of their length. Most adults weigh 10–11 pounds, as much as three times the size of an island fox.

Sacramento Valley red fox; photo courtesy Ben Sacks/UC Davis

Red foxes prefer habitat along edge environments where two habitat types meet, such as the intersection of open meadows and woodlands. In the west, red foxes are primarily found in higher, sub-alpine elevations. In California there are two native sub-species, the Sierra Nevada red fox and the newly described Sacramento Valley red fox. These two native red fox populations are small and geographically isolated (like being on an island). The study of island fox populations has played an important role in helping biologists evaluate the vulnerability of these red foxes to survive into the future.

Red foxes thrive near human settlements, most likely due to the protections humans provide against the foxes main predators: coyotes, bears, and mountain lions.

Red foxes are primarily active at twilight and night, although they may be seen during the day when foraging to feed their young. While omnivorous, their diet consists primarily of rodents, including voles, pocket gophers, and deer mice, as well as cottontail rabbits, jackrabbits, and snowshoe hairs. Like island foxes, red foxes readily eat fruits when they are in season. In some areas, fruits make up 100% of their diet! They commonly consume blueberries, blackberries, and raspberries, as well as apples, grapes, and even acorns.

Like many canids, North American foxes are basically monogamous, and the red fox is no different. Mating occurs between December and April. Pups are born between April and May. (Similar to island foxes.) The typical litter size is 3–6 pups. The male initially participates in feeding and rearing the kits, but moves on as the kits mature.

Red foxes are an adaptable and successful species. They have been extensively studied and their populations are stable apart from the two California sub-species. These beautiful animals extrude the cuddle factor more than any other fox species. (Well, except maybe island foxes.)

San Clemente Island fox

How is the Island Fox Unique?

Coming up next: Gemini Foxes: Kit Fox and Swift Fox;

Series installments:

How is the Island Fox Unique?

Gemini Foxes: Kit Fox and Swift Fox

Arctic Fox: Fox of the Tundra

The Island Fox's Origin - The Gray Fox

 

References:

Cyper, B.L. 2003. "Foxes (Vulpes species, Urocyon species and Alopex lagopus)." In Wild Mammals of North America: Biology, Management, and Conservation, 2nd edition by G. Feldhamer, B. Thompson, and J. Chapman (eds), pg 511–546. Baltimore: Johns Hopkins University Press.

Elbroch, M. and K. Rinehart. 2001. Behavior of North American Mammals. pg 105–111. Peterson Reference Guides.

Henry, J. D. 1996. Living on the Edge, Foxes. Minocqua, WI: Northword Press.

Saunders, D. A. 1988. "Red Fox: (Vulpes vulpes desmarest)." In Adirondack Mammals, pg 216. New York: State University of New York, College of Environmental Science and Forestry.