Foxes are small-to-medium-sized omnivorous mammals belonging to the Canidae family, which also includes dogs, wolves, and coyotes. The term “fox” is a general descriptor for over 20 species across several genera, including the “true foxes” of the genus Vulpes and other fox-like canids like the Gray Fox (Urocyon) and South American foxes (Lycalopex). This diversity reflects a remarkable ability to adapt to nearly every terrestrial environment on Earth, resulting in a global distribution that spans every continent except Antarctica. Fox species have evolved unique traits to thrive in specialized habitats, from the extreme cold of the Arctic tundra to the scorching heat of the Sahara Desert.
The Red Fox: Global Dominance and Adaptation
The Red Fox, Vulpes vulpes, possesses the largest natural distribution of any non-human land mammal, establishing a baseline for the global fox map. Its native range covers the entire Northern Hemisphere, stretching across almost all of Europe, temperate Asia, North America, and extending into parts of North Africa. Within North America, the Red Fox is found widely across Canada, Alaska, and the northern and eastern United States.
This species’ remarkable success stems from its generalist nature, allowing it to occupy a vast array of habitats, including forests, mountains, grasslands, and even deserts. It is also highly successful in human-modified environments and is classified as a resident urban carnivore in many cities worldwide.
Beyond its native Holarctic range, the Red Fox was introduced to Australia in the mid-1800s for sport, where it rapidly colonized the continent. Within about 60 years, it spread across most of Australia, excluding the tropical north and Tasmania, where eradication efforts are ongoing. This introduced population is listed among the “world’s 100 worst invasive species” due to its devastating impact on native Australian fauna, such as small marsupials.
Polar and Arid Specialists
In contrast to the Red Fox’s generalist range are species that have specialized to survive in the planet’s most extreme temperature zones: the Arctic and major deserts. The Arctic Fox, Vulpes lagopus, is a circumpolar species found exclusively in the Arctic tundra biome of the Northern Hemisphere. Its range includes the northernmost reaches of Europe, Asia, and North America, spanning countries and regions like Siberia, Canada, Greenland, Iceland, and Scandinavia.
This animal is uniquely adapted to the cold, inhabiting tundra and pack ice, and it is even sighted on sea ice close to the North Pole. The Arctic Fox is the only terrestrial mammal native to Iceland, having arrived by walking across the frozen sea ice at the end of the last ice age.
At the opposite thermal extreme, the Fennec Fox, Vulpes zerda, is a specialist of the arid regions of North Africa. This small canid is found throughout the Sahara Desert, with its range extending from the Western Sahara and Mauritania eastward to the Sinai Peninsula. Its most distinctive features are its disproportionately large ears, which function to dissipate heat and help locate prey moving underground.
Another desert specialist in North America is the Kit Fox, Vulpes macrotis, which inhabits the arid and semi-arid regions of the southwestern United States and northern Mexico. Its distribution includes the desert scrub and grasslands of states like Oregon, Nevada, Utah, Arizona, and New Mexico, extending south into Mexico.
North and South American Endemics
The North and South American continents are home to several fox species with ranges geographically distinct from the globally dominant Red Fox. The Gray Fox, Urocyon cinereoargenteus, has a broad distribution spanning from the southern edge of central and eastern Canada, through much of the United States and Mexico, and continuing south into northern South America, reaching Venezuela and Colombia.
It is unique among canids for its ability to climb trees, an adaptation that assists in foraging and evading predators in its preferred wooded and brushy habitats. While its range overlaps with the Red Fox in many areas of North America, the Gray Fox tends to prefer denser woodland and scrub. The Gray Fox’s presence in parts of the northern Andes makes it the only canid species whose natural range spans both North and South America.
South America hosts a separate genus of fox-like canids, Lycalopex, often referred to as “South American foxes” or “zorros.” These are not true foxes but resemble them due to convergent evolution.
The Culpeo, Lycalopex culpaeus, is the second-largest canid on the continent and has an extensive range along the Andes Mountains, from Ecuador and Peru south through Chile and Argentina, including the Patagonian steppe. Another species, Darwin’s Fox (Lycalopex fulvipes), is highly restricted, found only in the temperate rainforests of southern Chile, primarily on Chiloé Island and in a few mainland coastal areas.