Many animals have tails. Even humans once had a small tail, which is still just visible at the end of the coxyx. Whilst we do not need a tail to balance or use as an extra limb, many animals have specialised tails which have evolved for purposes which are important to the animal’s survival.
Monkeys, as opposed to apes, have tails which can curl, offer strongholds and support the animal’s weight. This is the prehensile tail and is also found in other groups such as lemurs. The tail is an additional limb and holds the animals when they are in trees and also is used for balance. It is one of the defining differences between monkeys and apes because apes (chimpanzees, gorillas and humans) do not have a prehensile tail.
The cat family have tails which are used for additional balance and to control drift when the animal leaps. The tail is an integral part of the balance of the animal and is extended when they run quickly and when they leap. In cats, the tail is an extension of the spine with bones almost to the tip and is strongly fortified with muscle tissue. Loss of a tail is not life-threatening but the cats have to adapt and it can spoil their chances of hunting successfully.
Dogs have tails and, like cats, also use them for comminicating to other dogs. Wolves use their tails to signal aggression, pleasure and a readiness to mate. Unlike cats, a dog’s tail is muscle with few bones and can be lost with little impact on balance. The practice of docking tails was carried out until recently on many breeds to increase their percieved attractiveness.
Many aminals including sheep, deer and cows have tails which they use to keep insects away from their nether regions. They also use them to signal a readiness to mate by rasing the tail, flicking their scent and exposing their reproductive areas.Hippos use their tails to flick waste to signal ownership of a territory.
Fish and sea mammals like dolphins, whales and seals possess muscle-packed tails with two types of muscle, one (red muscle) for slow constant swimming and white muscle which is used for quick bursts of speed such as when a shark strikes prey.
Birds have tails for balance and they are also used to control direction and reduce speed in flight and when stooping on prey. Watching a kestrel hunting really allows you to see the use of the tail in flight and to control the speed of the stoop onto their prey. The tail is vital in allowing them to pin point the strike and also helps balance when they perch.
Chameleons and other climbing reptiles use their tails as a limb to hold, curl around branches and for balance and crocodiles use their hugely muscular tails for incredible bursts of speed when they strike prey. Their tailis strong enough to life the weight of a 1.2 tonne animal clean out of the water.
Tails are incredibly useful to many animals. They are used as signals, for balance, to control sideways movement in flight and running and , though we have long lost ours, they remain a vital part of many animals’ anatomy.