Females' territories may either be exclusive or overlapping, with range size being dependent on the density of the prey species. Males' ranges are larger and usually overlap the ranges of several females. They are active chiefly at night. They can leap distances of 16 to 20 feet, and 6 feet high. Tigers are not unsocial, despite the fact that they usually hunt alone and, in fact, often come together to share a kill. Neighbors often have amicable relationships. Females spend a large portion of their lives accompanied by cubs. Tigers are tolerant of a wide range of climates and habitats, only requiring adequate cover, water, and prey. They depend primarily on sight and hearing for hunting, and kill by strangulation or a bite to the back of the neck. They will bury the remains of a carcass and may return to feed from it for several days. Tigers can eat as much as 88 pounds of meat at one time. Although they are excellent hunters, only 10% of all attempts result in a kill. They lead a nomadic life, travelling long distances in the winter in search of food. They can endure intense frost, but when travelling in deep snow they tire rapidly, and must rest often. Vocalizations include woofs, roars, rasping grunts, purring, soft grunts or puffing sounds called "prusten."