The snow leopard, or ounce (Uncia uncia), is the only species of the genus Uncia. These big brownish-grey cats with large dark-brown rosettes differ from leopards proper (Panthera pardus) by the colour and rich texture of their fur, as well as by the length of their tail – about three quarters of its body length, which is 120-125 centimetres. An adult snow leopard weighs up to 45 kilograms. Their colour and size do not vary by region. There are two scientifically recognised subspecies, but they are generally considered one species.

Snow leopards are found in the mountains of Central Asian (Himalayas) and southern Siberia at middle to high altitudes, their habitat range stretching across parts of 13 countries – Afghanistan, Bhutan, Burma, China, India, Kazakhstan, Kyrgyzstan, Mongolia, Nepal, Pakistan, Russia, Tajikistan, and Uzbekistan. The animal lives primarily in subalpine and alpine altitudes up to 5,000 metres above sea level, and prefers gorges with dense undergrowth, bare uplands, gravel patches, and fields of snow.

Less fertile than the other felids, female snow leopards do not give birth every year. The mating season is from March through May, and gestation lasts 93-110 days, so cubs are usually born in late spring or early summer. There are one to five cubs in a litter – most often, two or three. They come into the world blind and deaf, weighing 450-500 grams, and feed only on their mother’s milk the first six weeks. The cubs follow their mother while she hunts as early as midsummer of their first year, while sexual maturity comes in the second or third year.

Adult snow leopards are considered solitary territorial animals, though females remain with their cubs for a rather long time. Dens are made in caves or rock clefts. Every snow leopard has its own territory, though the species is less aggressive in defence of its territory than other felids when the intruder is of the same species. The territories of one to three females may overlap with an adult male’s domain. Snow leopards mark the territory in a variety of ways, and they make regular rounds of their hunting grounds, always moving along the same paths. As it roams through the grazing grounds of its prey or descends to the lowlands, a snow leopard generally moves along mountain ridge or streams. Its established routes are usually very long, so the leopard revisits each spot once every several days.

The snow leopard is at the top of the food pyramid, with rival predators offering little to no competition. It can kill prey three times its own weight. Usually, snow leopards stalk their prey, or ambush it beside a path, by salt patches and watering places, or among the rocks. When the prey is at a distance of several dozen meters, the snow leopard springs from its hiding place and quickly overtakes it, bounding 6-7 metres at a time. Snow leopards either will not pursue prey that has escaped, or they will give up after 300 metres. In late summer, autumn and early winter, leopards usually hunt in twos or threes – a mother and her young. In lean years, they often approach human settlements to kill livestock. Mountain goats and rams, roe deer, wild boar, marmots, hares and snowcocks make up the greater part of their diet, complemented by grass and leaves in summertime.

Russia is home to the northernmost snow leopard population. They live in the Altai, Sayan and Tuvinian mountains in southern Siberia. Experts estimated the population at 150-200 in 2002. There is concern that since then the number of snow leopards may have decreased threefold. Information about their habitat and population structure was obtained in extensive but overly generalised studies carried out by zoologists of the Russian Academy of Sciences, with the help of hunters and experts working at several nature reserves to implement a World Wildlife Fund project to protect the fauna of the Altai-Hangai-Sayan area in 1998-1999.