The underside of the tail is pale grey with a straw-coloured tint.
Although the red fox tends to kill smaller predators, including other fox species, it is vulnerable to attack from larger predators, such as wolves, coyotes, golden jackals and medium- and large-sized felines.Compare with West Frisian foks, Dutch vos, and German Fuchs. Red foxes present in Britain (and therefore Australia) are usually ascribed to this subspecies, though many populations there display a great degree of tooth compaction not present in continental European populations. Their skulls are fairly narrow and elongated, with small braincases. Sexual dimorphism of the skull is more pronounced than in corsac foxes, with female red foxes tending to have smaller skulls than males, with wider nasal regions and hard palates, as well as having larger canines.This, in turn, derives from Proto-Indo-European *puḱ- 'thick-haired; tail'. The latter clade has been separated from all other red fox populations since the last glacial maximum, and may possess unique ecological or physiological adaptations. In addition, no evidence is seen of interbreeding of eastern red foxes in California with the montane Sierra Nevada red fox V. necator or other populations in the Intermountain West (between the Rocky Mountains to the east and the Cascade and Sierra Nevada ranges to the west. A large subspecies, the colour along its spine is light, dull yellowish-reddish with a strongly developed white ripple and greyish longitudinal stripes on the anterior side of the limbs. However, relative to dimensions, red foxes are much lighter than similarly sized dogs of the genus Canis.Too small to pose a threat to humans, it has extensively benefited from the presence of human habitation, and has successfully colonised many suburban and urban areas. vulpes by its smaller size, proportionately smaller skull and teeth, and coarser fur.Domestication of the Red fox is also underway in Russia, and has resulted in the Domesticated red fox. caucasica, its fur is pale yellow or light grey, sometimes brownish-reddish and is fluffier and denser than that of other Caucasian subspecies. The hairs on the sole of the feet are copiously mixed with softer, woolly hairs. vulpes, it has smaller teeth and more widely spaced premolars.The backs of the ears are black or brownish-reddish, while the inner surface is whitish.The top of the tail is brownish-reddish, but lighter in colour than the back and flanks.The red fox is considered a more specialised form of Vulpes than the Afghan, corsac and Bengal foxes in the direction of size and adaptation to carnivory; the skull displays much fewer neotenous traits than in other species, and its facial area is more developed. The fur is rusty grey or rusty brown, with a brighter rusty stripe along the spine. A large subspecies, it is the most brightly coloured of Old World red foxes, the fur being saturated bright-reddish and almost lacking the bright ripple along the back and flanks. A large subspecies, its coat is variable in colour, ranging from reddish to red-grey and nearly grey. Weights range from 2.2–14 kg (5–31 lb), with vixens typically weighing 15–20% less than males.The earliest fossil remains of the modern species date back to the mid-Pleistocene in association with the refuse of early human settlements. The southern (or montane) refugium occurs in the subalpine parklands and alpine meadows of the Rocky Mountains, the Cascade Range, and Sierra Nevada. The forefoot print measures 60 mm (2.4 in) in length and 45 mm (1.8 in) in width, while the hind foot print measures 55 mm (2.2 in) long and 38 mm (1.5 in) wide.Likewise, Portuguese: from rabo 'tail', Lithuanian uodẽgis from uodegà 'tail', and Ojibwa waagosh from waa, which refers to the up and down "bounce" or flickering of an animal or its tail. The fur is bright red with a strongly developed whitish and yellow ripple on the lower back. On average, adults measure 35–50 cm (14–20 in) high at the shoulder and 45–90 cm (18–35 in) in body length with tails measuring 30–55.5 cm (11.8–21.9 in).The scientific term vulpes derives from the Latin word for fox, and gives the adjectives vulpine and vulpecular. Scandinavia and the northern and middle (forest) districts of the European part of the former Soviet Union, southwards to forest-steppe and eastwards approximately to the Urals, and probably Central and Western Europe A small subspecies weighing 4 kg, its maximum skull length is 132–39 mm in males and 121–26 mm in females. The ears measure 7.7–12.5 cm (3–5 in) and the hind feet 12–18.5 cm (5–7 in).