Most mammals can swim, including lions, leopards and cheetahs. Being able to swim is quite different from being able to swim well though. Most of the big cats tend to avoid water as they are adapted to hunt on land.
Tigers, on the other hand, live in lush tropical jungles with lots of wide rivers. (The other big cat that swims well is the jaguar – another forest dweller.) Prey animals in forest environments don’t form nice convenient herds, so tigers have to go looking for their food.
Tigers can have territories as large as 100 square kilometres (37 square miles) and being able to swim across rivers is a big evolutionary advantage.
Tigers can swim rivers as wide as seven kilometres (4.3 miles) across and might swim up to 29 kilometres (18 miles) per day as they patrol their territory.
Answered by Luis Villazon