Most animals have tails, and it is often something we accept, but why do some have tails, and why do some animals not have tails? Due to evolution, are they simply a crossover, or do animals need their tails?
Animals have adapted to use their tails for movement, hunting, defense, communication, and aid balance. Every species has a unique use of its tail, and many animals struggle when their tail is injured or lost.
To learn more about how animals use their tails, please read on.
The most common use of a tail is for locomotion. Fish, for example, use their tails for both forward propulsion through the water and to change direction.
Crocodiles and alligators have muscular tails with flat, paddle-like ends, which help to give them additional speed in the water. Their appendages are so strong that they can even use them to propel their entire body upwards out of the water like a torpedo.
The North American manatee is the perfect example of aquatic locomotion. Although mammals, manatees have adapted well to life in the water. Instead of hind legs, they have a broad, flat paddle-like tail to propel themselves forward. They create a gentle forward movement through the water by moving their tail up and down. Since manatees are slow, gentle creatures, they do not need flippers that generate high speed.
Primates are one of the most well-known animals to use their tails for movement. However, there have been no primates native to North America for approximately 40 million years. During this time, the climate in North America was tropical – hot and humid, just like South America and perfect for many primate species. When the Drake Passage broke apart, the Pacific and Atlantic oceans mixed, drastically reducing the Earth’s temperature and causing a mass extinction. Only monkeys living along the equator survived as this region maintained its tropical climate.
Of all the uses of a tail, balance is one of the most common. Many species need their tail for balance. Squirrels have many uses for their tail, but balance is essential. Jumping large distances between tree branches can easily alter a squirrel’s balance, so they use their tail as a rudder to control their body movement in the air.
Cats are experts at utilizing their tails for balance. You may spot a cat walking along the top of a fence or narrow wall and flicking its tail to one side as they move. Whether a domestic cat or a wild cougar, cats use their tails as a counterbalance to keep their body weight steady. Cats also use their tails as a rudder to jump across large gaps or down a high drop. By moving its tail sideways and down towards its feet, a cat can turn their body and ensure that they always land on its feet.
Protection or Hunting
California is home to rubber boa snakes. These fascinating snakes have a flat, blunt tail that has a striking resemblance to their head. The snake will curl up with its head safely coiled within its body and its tail exposed. Since it looks like the head, any predator would strike the wrong end. Rubber boas secrete a nasty substance from their tail that will cause the predator to leave the snake alone.
As we have already learned, squirrels have many uses for their tails. Protection against the elements is a crucial adaptation. A squirrel’s tail is long and bushy, perfect for wrapping around the body and conserving heat. This is especially helpful during the cold winter months when squirrels hibernate.
North American beavers use their tail to warn others when danger is near. They slap their flat tail against the water’s surface to alert them that a predator or other threat is close. Similarly, whitetail deer use their tails to signal danger. If they hear or see a potential threat, the deer will lift its tail straight upward, exposing the white underside. This is a clear message to their herd to be alert or to flee.
Many reptile species have a unique feature that helps them escape predators. Small lizards such as geckos can drop their tails when caught by a predator, giving the gecko a second chance to get away. The wound will heal quickly, and a new one will grow in around 3-4 months. The new tail will never look quite like the original, but it will still function similarly
The giant desert hairy scorpion, or giant Arizona scorpion, is the largest species found in North America. They use their tail for both protection and to catch prey. When the scorpion finds a prey animal, it grabs hold with its pincers and strikes by arcing its tail and body over its head. The tail delivers venom into the prey animal, causing paralysis. While their main prey is insects, they occasionally eat smaller scorpions, lizards, and even birds.
When threatened by a predator, the giant desert hairy scorpion will hold its pincer out widely to make it appear larger and hold the tail over its head, ready to strike. The actual strike is quick as the scorpion does not want to risk being grabbed by the tail.
The peacock is perhaps the most famous animal to use its tail for display purposes. Although peafowl is not native to North America, there are many feral populations, and they can often be found roaming in parks.
A peacock is a male peafowl, with females referred to as peahens. The males are the ones with elaborate tails. They use their tails during the courtship of females or display their dominance over other males. A Peacock’s tail is typically carried closed and will trail on the ground. When the Peacock displays to other birds, he lifts his tail straight up and opens it out like a fan.
An open tail is a complete semi-circle touching the floor on either side of the bird’s body. They rustle their feathers as an addition to the visual display, but this has another feature. Peacocks can create infrasound by rustling their tail feathers. Humans cannot hear infrasound, but many animals can. It is believed that infrasound is used to attract close mates out of view, so the tail display alone would be ineffective.
When it comes to displays, dogs are experts. They use their tails to communicate with other dogs, which can help to prevent fights from occurring. Many people incorrectly believe that a wagging tail means a dog is happy. This is not the case. When a dog wags his tail, he is signaling that he is engaged with his environment and is willing to interact.
A high loose tail shows the dog is confident and relaxed, whereas a stiff tail signals tension regarding their situation. A tail held low or between the legs shows fear or submission. If a dog wags its tail quickly, this generally indicates that he is comfortable with his environment, but slow wags can signal that the dog is not satisfied and may react hostile.
It is common for dog owners whose dogs have lost their tails to encounter altercations with other dogs. A dog without a tail cannot effectively display their feelings to other dogs, which can often escalate into unfriendly interactions.
While most animals store fat within their bodies to use as energy, a small number of reptiles can use their tail as fat storage.
The Gila monster, native to the southwestern states of North America, uses its tails as a fat store. During times when food is scarce, they can use their tail as a source of energy until food becomes available. The more overweight a Gila monster’s tail, the healthier the animal is.
It is not just Gila monsters that can do this. Certain species of alligators can also store fat in their tails. Alligators do not need to feed often to survive, so they store additional calories on the underside of their tail in the form of fat. Their fat store can be used for as long as two years as energy sources when there is little food available.
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Bryan Harding is a member of the American Society of Mammalogists and a member of the American Birding Association. Bryan is especially fond of mammals and has studied and worked with them around the world. Bryan serves as owner, writer, and publisher of North American Nature.