The red fox (Vulpes vulpes) is the largest of the true foxes and one of the most widely distributed members of the order Carnivora, being present across the entire Northern Hemisphere, plus parts of North Africa. It is listed as least concern by the IUCN. Its range has increased alongside human expansion, having been introduced to Australia, where it is considered harmful to native mammals and bird populations. Due to its presence in Australia, it is included on the list of the “world’s 100 worst invasive species”. It should be noted, that humans have usually been either the direct cause of red foxes invading a new country, or have allowed them to migrate as a result of climate change.
The red fox originated from smaller-sized ancestors from Eurasia during the Middle Villafranchian period, and colonised North America shortly after the Wisconsin glaciation. Among the true foxes, the red fox represents a more progressive form in the direction of carnivory. Apart from its large size, the red fox is distinguished from other fox species by its ability to adapt quickly to new environments. Despite its name, the species often produces individuals with other colourings, including leucistic and melanistic individuals. Forty-five subspecies are currently recognised, which are divided into two categories: the large northern foxes and the small, basal southern grey desert foxes of Asia and North Africa.