what is the average weight of a red fox
Red fox Red foxes are the largest species of the genus Vulpes.[37] However, relative to dimensions, red foxes are much lighter than similarly sized dogs of the genus Canis. Their limb bones, for example, weigh 30 percent less per unit area of bone than expected for similarly sized dogs.[38] They display significant individual, sexual, age and geographical variation in size. 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 ears measure 7.7–12.5 cm (3–5 in) and the hind feet 12–18.5 cm (5–7 in). Weights range from 2.2–14 kg (5–31 lb), with vixens typically weighing 15–20% less than males.[39][40] Adult red foxes have skulls measuring 129–167 mm (5.1–6.6 in), while those of vixens measure 128–159 mm (5.0–6.3 in).[6] 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. They trot at a speed of 6–13 km/h (4–8 mph), and have a maximum running speed of 50 km/h (30 mph). They have a stride of 25–35 cm (9.8–13.8 in) when walking at a normal pace.[38]:36 North American red foxes are generally lightly built, with comparatively long bodies for their mass and have a high degree of sexual dimorphism. British red foxes are heavily built, but short, while continental European red foxes are closer to the general average among red fox populations.[41] The largest red fox on record in Great Britain was a 17.2 kg (38 lb), 1.4-metre (4 ft 7 in) long male, killed in Aberdeenshire, Scotland, in early 2012.[42]
Fox Foxes are generally smaller than other members of the family Canidae such as wolves, jackals, and domestic dogs. For example, in the largest species, the red fox, males weigh on average between 4.1 and 8.7 kg (9.0 and 19.2 lb),[6] while the smallest species, the fennec fox, weighs just 0.7 to 1.6 kg (1.5 to 3.5 lb).[7] Fox-like features typically include a triangular face, pointed ears, an elongated rostrum, and a bushy tail. Foxes are digitigrade, and thus, walk on their toes. Unlike most members of the family Canidae, foxes have partially retractable claws.[8] Fox vibrissae, or whiskers, are black. The whiskers on the muzzle, mystaciae vibrissae, average 100–110 mm (3.9–4.3 in) long, while the whiskers everywhere else on the head average to be shorter in length. Whiskers (carpal vibrissae) are also on the forelimbs and average 40 mm (1.6 in) long, pointing downward and backward.[2] Other physical characteristics vary according to habitat and adaptive significance.
Red fox The red fox originated from smaller-sized ancestors from Eurasia during the Middle Villafranchian period,[4] and colonised North America shortly after the Wisconsin glaciation.[5] Among the true foxes, the red fox represents a more progressive form in the direction of carnivory.[6] 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 albinos and melanists.[6] Forty-five subspecies are currently recognised,[7] which are divided into two categories: the large northern foxes, and the small, basal southern foxes of Asia and North Africa.[6]
Standard deviation Let X be a random variable with mean value Î¼:
Red fox Red foxes are wide-ranging animals, whose range covers nearly 70 million km2 (27 million sq mi). They are distributed across the entire Northern Hemisphere from the Arctic Circle to North Africa, Central America, and Asia. They are absent in Iceland, the Arctic islands, some parts of Siberia, and in extreme deserts.[1]
Red fox The average litter size consists of four to six kits, though litters of up to 13 kits have occurred.[6] Large litters are typical in areas where fox mortality is high.[38]:93 Kits are born blind, deaf and toothless, with dark brown fluffy fur. At birth, they weigh 56–110 g (2.0–3.9 oz) and measure 14.5 cm (5.7 in) in body length and 7.5 cm (3.0 in) in tail length. At birth, they are short-legged, large-headed and have broad chests.[6] Mothers remain with the kits for 2–3 weeks, as they are unable to thermoregulate. During this period, the fathers or barren vixens feed the mothers.[8] Vixens are very protective of their kits, and have been known to even fight off terriers in their defence.[23]:21–22 If the mother dies before the kits are independent, the father takes over as their provider.[23]:13 The kits' eyes open after 13–15 days, during which time their ear canals open and their upper teeth erupt, with the lower teeth emerging 3–4 days later.[6] Their eyes are initially blue, but change to amber at 4–5 weeks. Coat colour begins to change at three weeks of age, when the black eye streak appears. By one month, red and white patches are apparent on their faces. During this time, their ears erect and their muzzles elongate.[8] Kits begin to leave their dens and experiment with solid food brought by their parents at the age of 3–4 weeks. The lactation period lasts 6–7 weeks.[6] Their woolly coats begin to be coated by shiny guard hairs after 8 weeks.[8] By the age of 3–4 months, the kits are long-legged, narrow-chested and sinewy. They reach adult proportions at the age of 6–7 months.[6] Some vixens may reach sexual maturity at the age of 9–10 months, thus bearing their first litters at one year of age.[6] In captivity, their longevity can be as long as 15 years, though in the wild they typically do not survive past 5 years of age.[50]