Question

the only species that can have its tail vertically up while walking?

Answer 1

hey mate,
 

Animals can use their tails to convey a wide range of emotions, from happiness to fear, and some can even use them as a weapon when threatened. But a much more frequent use of the tail is to maintain balance. Much like the way a circus performer walking a tightrope might use an umbrella to steady himself, an animal can use his tail to remain stable.

Beaver

One of the beaver's most distinguishable features is its wide, flat tail that it uses to slap against water when it feels that danger is near. The beaver tail also helps the animal maneuver when swimming, acting as a makeshift rudder. When sitting, its tail helps to keep it propped up and, when collecting materials for use in building a dam, the tail acts as a leveraging device to keep the beaver's body weight balanced.

Squirrel

Squirrels use their big, bushy tails to help them remain balanced when jumping from tree to tree and running along electrical wires. The size of a squirrel's tail also helps it maintain its balance when making fast turns to escape a perceived threat.

Kangaroo

Kangaroos are easily recognizable by their thick, powerful tails, which play a huge part in keeping this marsupial balanced. Certain species of kangaroo can jump up to 30 feet in the air while hopping from place to place and the tail helps the animal to do so without faltering. When walking at a more leisurely pace, the kangaroo uses its hind and front legs simultaneously while its tail helps it stay upright.

Cougar

The cougar, one of the largest wild cats in the western hemisphere, has a tail that is about one-third of its overall body length. Its heavy tail helps to counterbalance its rapid movements as it is in pursuit of prey, keeping it balanced throughout the duration of the chase and kill.