The hill fox[1] (Vulpes vulpes montana),[2] also known as the hill red fox,[1] or the Himalayan red fox,[3] is a subspecies of the red fox that is native to parts of the Himalayan Mountain Range and the Karakoram Mountain Range. It has two noticeable populations: one in northeastern India, far southern Nepal, and far northern Bangladesh. The other is in portions of far northwestern India, and northeastern Pakistan. Populations may be present in far southwestern China, and in other areas of the Himalayas.[4] Its natural range is made up of rocky terrain, low grasslands, and tundra within a temperate climate.[5]
The hill fox is differentiated from the nominate subspecies by having a smaller body, smaller skull, and teeth, and by having rough or coarse hair. Its foot hair is mixed with softer, woolly hair.[6] It is occasionally known to build dens near urbanized human areas.[7] Researchers in the Shigar Valley of the Karakoram Range in Pakistan studied the foxes' habits and den locations. Their study reported that, in the resting state, 83.33% of the foxes had a den in a grass or bare habitat.[7]
Many hill foxes are high-altitude animals with adaptations suited to their environment. Studies have shown that many high-altitude animals reduce oxygen demand by suppressing total metabolism to compensate for a reduced cellular oxygen supply in response to hypoxia.[8]
Several studies have examined the subspecies' genetic information to understand its evolution and adaptation to high-altitude habitats. One study used blood samples from a wild female red fox captured near Lhasa in Tibet, China; the Qinghai–Tibet Plateau is the highest plateau in the world, with an average elevation above 3,500 m.[9] The researchers analyzed the gene sequences and identified a gene associated with the animal's ability to adapt to its environment.
