The red fox (Vulpes vulpes) typically dominate other fox species. Arctic foxes generally escape competition from red foxes by living farther north, where food is too scarce to support the larger-bodied red species. Although the red species' northern limit is linked to the availability of food, the Arctic species' southern range is limited by the presence of the former. Red and Arctic foxes were both introduced to almost every island from the Aleutian Islands to the Alexander Archipelago during the 1830sā1930s by fur companies. The red foxes invariably displaced the Arctic foxes, with one male red fox having been reported to have killed off all resident Arctic foxes on a small island in 1866. Where they are sympatric, Arctic foxes may also escape competition by feeding on lemmings and flotsam, rather than voles, as favoured by red foxes. Both species will kill each other's kits, given the opportunity.
Red foxes are serious competitors of corsac foxes, as they hunt the same prey all year. The red species is also stronger, is better adapted to hunting in snow deeper than 10 cm (4 in) and is more effective in hunting and catching medium to large-sized rodents. Corsac foxes seem to only outcompete red foxes in semi-desert and steppe areas. In Israel, Blanford's foxes escape competition with red foxes by restricting themselves to rocky cliffs and actively avoiding the open plains inhabited by red foxes.:84ā85 Red foxes dominate kit and swift foxes. Kit foxes usually avoid competition with their larger cousins by living in more arid environments, though red foxes have been increasing in ranges formerly occupied by kit foxes due to human-induced environmental changes. Red foxes will kill both species, and compete for food and den sites. Grey foxes are exceptional, as they dominate red foxes wherever their ranges meet. Historically, interactions between the two species were rare, as grey foxes favoured heavily wooded or semiarid habitats as opposed to the open and mesic ones preferred by red foxes. However, interactions have become more frequent due to deforestation allowing red foxes to colonise grey fox-inhabited areas.
Wolves may kill and eat red foxes in disputes over carcasses. In areas in North America where red fox and coyote populations are sympatric, fox ranges tend to be located outside coyote territories. The principal cause of this separation is believed to be active avoidance of coyotes by the foxes. Interactions between the two species vary in nature, ranging from active antagonism to indifference. The majority of aggressive encounters are initiated by coyotes, and there are few reports of red foxes acting aggressively toward coyotes except when attacked or when their kits were approached. Foxes and coyotes have sometimes been seen feeding together. In Israel, red foxes share their habitat with golden jackals. Where their ranges meet, the two canids compete due to near identical diets. Foxes ignore jackal scents or tracks in their territories, and avoid close physical proximity with jackals themselves. In areas where jackals become very abundant, the population of foxes decreases significantly, apparently because of competitive exclusion.
Red foxes dominate raccoon dogs, sometimes killing their kits or biting adults to death. Cases are known of foxes killing raccoon dogs entering their dens. Both species compete for mouse-like prey. This competition reaches a peak during early spring, when food is scarce. In Tartaria, red fox predation accounted for 11.1% of deaths among 54 raccoon dogs, and amounted to 14.3% of 186 raccoon dog deaths in north-western Russia.
Red foxes may kill small mustelids like weasels, stone martens, pine martens, stoats, kolonoks, polecats and young sables. Eurasian badgers may live alongside red foxes in isolated sections of large burrows. It is possible that the two species tolerate each other out of mutualism; foxes provide badgers with food scraps, while badgers maintain the shared burrow's cleanliness.:15 However, cases are known of badgers driving vixens from their dens and destroying their litters without eating them. Wolverines may kill red foxes, often while the latter are sleeping or near carrion. Foxes in turn may kill unattended young wolverines.
Red foxes may compete with striped hyenas on large carcasses. Red foxes may give way to hyenas on unopened carcasses, as the latter's stronger jaws can easily tear open flesh that is too tough for foxes. Foxes may harass hyenas, using their smaller size and greater speed to avoid the hyena's attacks. Sometimes, foxes seem to deliberately torment hyenas even when there is no food at stake. Some foxes may mistime their attacks, and are killed.:77ā79 Fox remains are often found in hyena dens, and hyenas may steal foxes from traps.
In Eurasia, red foxes may be preyed upon by leopards, caracals and Eurasian lynxes. The lynxes chase red foxes into deep snow, where their longer legs and larger paws give them an advantage over foxes, especially when the depth of the snow exceeds one metre. In the Velikoluki district in Russia, red foxes are absent or are seen only occasionally where lynxes establish permanent territories. Researchers consider lynxes to represent considerably less danger to red foxes than wolves do. North American felid predators of red foxes include cougars, Canadian lynxes and bobcats. Occasionally, large raptors such as Eurasian eagle owls will prey on young foxes, while golden eagles have been known to kill adults.