Window on Nature
By Lowell and Kaye Christie, F47246
These appendages tell a story in the varied ways animals use them.
Outside our window the rain begins to fall a bit harder, but the local gray squirrel just uses its tail as an umbrella to keep the drops from bouncing off its head. Evidently, the acorns it is collecting are more important than the slight discomfort of a little moisture. During drier weather, the tail becomes a parasol, providing shade from the sun as the squirrel forages under the oaks.
Tonight when it grows cold, the squirrel will use its tail as a warm comforter to keep out the chill. Animal tails come in many sizes and shapes, and if you watch closely you’ll find they have multiple uses.
Birds use their tails both in flight and in foraging. Larger birds use their tails as a rudder to help change direction during a glide. When a smaller bird comes in for a landing on a branch, the tail is used as an air break, helping to cancel the forward motion right when its feet reach their target.
Watch a woodpecker use its tail for support as it climbs a tree in search of insects. The two feet and the tail form a tripod, almost as though the bird had a third foot. This tail support is so important that the woodpecker molts its tail feathers in stages so it always has something to lean on.
Other critters also make efficient use of their tails while climbing. On the West Coast, the southern alligator lizard wraps its prehensile tail (adapted for grasping) around small branches when it decides to leave the ground. This tail may be as much as 10 inches long, assuming the original tail wasn’t claimed by a predator.
Like many lizards, this species may shed its tail when attacked. If grabbed, the tail snaps off and continues to wiggle, providing enough distraction to the predator to allow the lizard to flee. Over time a replacement tail will grow. It’s usually a slightly different color and a bit shorter, but the lizard probably considers this a better alternative to being eaten.
An even more impressive example of a prehensile tail is that of the opossum. The opossum is one of the oldest mammals; some sources claim it has been around for more than 70 million years. It has opposable “thumbs” (actually a hallux or big toe) on its rear feet. This gives the critter excellent grasping capabilities that help it maneuver while climbing. It also can get a grip with its tail.
The opossum tail is not strong enough to completely support the heavy animal, but since it spends a lot of time in trees, it uses the appendage like another limb. And when building a nest, the opossum even carries leaves and other materials with its tail.
In addition to utilitarian functions, some tails come in handy for attracting a mate. A prime example in this country is the wild turkey. The turkey is the largest North American game bird, and when the male spreads his tail to attract a female, he looks almost twice his size. A turkey’s tail consists of 18 feathers, each 12 to 15 inches long. Because of the way a young turkey molts, first-year birds have a “bump” in the middle of the fan where the center feathers are longer than the others. By the bird’s second year, the tail feathers are all the same length.
Although birds use their tails to assist in flying, water dwellers tend to use the tail as their primary means of propulsion. Fish move their tails back and forth by contracting and relaxing muscles on alternating sides of their bodies. Whales and dolphins do the same, but their tails (called flukes) are horizontal, and so they move up and down instead of side to side. The basic action is the same, whether that of a tiny minnow or the giant blue whale with a fluke measuring up to 25 feet wide.
Another swimmer, the beaver, is well known for its distinctive tail. Wide and flat, it can be used as a rudder or, in conjunction with the feet, as a means of propulsion while in the water. On dry land the beaver uses the tail as a prop when it stands on its hind legs to chew through branches or tree trunks.
When a beaver senses danger, it uses its tail as a warning device, slapping it hard on the surface of the water. The explosive sound warns nearby beavers, along with other creatures that live near the pond, to be on the alert.
The tail is used as a warning by many animals. Pay attention should you see a skunk turn its back and raise its tail. If it also stomps its front feet, that’s all the notice you are likely to receive before getting sprayed. Then there is the porcupine. With its piercing quills as its main defense, this animal seldom has to threaten, but when the porcupine goes into battle, it leads with its prickly tail.
As you can readily see, there is much you can learn about animals and their behavior by paying attention to tails. The deer that frequent our backyard quickly raise their tails when they sense a strange sound or smell. The white under the tail acts as an alarm signal. By being aware, we immediately start looking for the intruder and often see wildlife we would otherwise miss.
Domestic animals use the same signals as those in the wild. If our cat flicks her tail quickly back and forth as she stares out the window, we can be sure there is some small creature in the area.
Tails tell tales. It’s just a matter of learning how to read them.