Although sometimes overlooked, a bird's tail is much more useful than you realize. Learn fascinating bird tail facts.
All About Bird Tail Feathers
Have you ever wondered what a bird’s tail is made of? It’s actually just feathers. Unlike animals such as cats or dogs, there are no bones or muscles back there, just a set of strong, flat feathers.
Most birds have 10 or 12 tail feathers, arranged in five or six pairs, from the central two to the outermost pair. The positions of the tail feathers are controlled by muscles at the rear of the body, and the bird can change the apparent shape of its tail by fanning the feathers out widely or folding them close together.
When the tail is folded, the outermost pair of feathers is on the bottom and the central ones are on top.
Rudders and Props
Tail feathers play important roles for birds that are flying or landing. For example, a bird coming in for a landing may pump its tail downward and fan it out wide to push against the air, helping it come to a quick stop.
Although their wings provide most of the lift and the forward motion, flying birds turn to one side or the other by shifting the position of their tail—as if turning a boat by operating the rudder at the back end. Species that are especially graceful and acrobatic in flight, such as barn swallows and common terns, may have long, deeply forked tails for extra-fine control. On the other hand, birds that fly rarely or not at all, such as kiwis and emus, usually have short, insignificant tail feathers.
Woodpeckers and some other tree-climbing birds demonstrate another practical use for tail feathers. As a woodpecker hitches its way up a tree trunk with a series of short hops, it presses its strong, stiff tail feathers against the tree with each hop, helping to prop itself up.
Unlike woodpeckers, chimney swifts don’t climb, but they cling to vertical surfaces inside chimneys or hollow trees, where the spiny tips of their tail feathers help hold them in place.
Flashing Signals to the Flock
Just as the taillights on a car can convey useful information to other drivers—such as turning or braking—a bird’s tail pattern can communicate with other members of its flock.
For example, the white outer tail feathers of a dark-eyed junco are hardly visible while the bird is hopping on the ground. But if it takes off suddenly, those white feathers flash like a beacon, alerting other members of the junco flock that danger may be approaching. Other birds that forage on the ground, such as meadowlarks and pipits, can create a similar effect.
A Bird Tail That Makes Music
Some birds make remarkable sounds with their tail feathers.
A Wilson’s snipe makes a hollow, bubbling whistle, known as “winnowing,” as it flies over its marshy habitat in spring. The snipe doesn’t make this sound with its voice; instead, it’s created by air vibrating its narrow outer tail feathers. Other species of snipes elsewhere in the world also make their own versions of this sound.
A male Anna’s hummingbird in its territorial and courtship display makes a steep dive from high in the air, pulling up at the bottom of the dive with a loud, explosive squeak. It took careful research for scientists to figure out that this hummingbird sound is produced by air passing over the outermost tail feathers.
Fine Tail Feathers for Flirting
Some of the most decorative tail feathers belong to male birds that use them in amazing courtship displays to woo females.
A Peruvian hummingbird called the marvelous spatuletail has two very long, wiry tail feathers, each with a broad, rounded racket at the tip. Some birds-of-paradise in New Guinea have tail feathers like long ribbons or wires, to go with their other elaborate plumes.
Australia’s superb lyrebird has a tail shaped like the ancient musical instrument, the lyre, with broad, curved outer feathers. Here in North America, the male scissor-tailed flycatcher shows off his long, streaming outer tail feathers as he performs an acrobatic sky dance in front of a prospective mate.
What might seem like the fanciest tails are not tail feathers at all. They represent a different set of feathers, known as the upper tail coverts. The flowing emerald-green train of the male resplendent quetzal is really made up of these coverts, which are much longer than the tail itself. The stunning fanlike display of a peacock, with big eyelike spots on dozens of long, wispy feathers, is also created by upper tail coverts. The tail itself, short and plain, is hidden underneath.
Of course, it doesn’t matter to the birds which feathers are involved, as long as the result is spectacular enough.
Are Bird Tail Feathers Replaceable?
Tail feathers eventually wear out, but they can be replaced. Most birds molt their tail feathers once a year, two at a time, with old ones falling out and fresh ones growing in their place. And if they lose feathers at other times, outside the normal molting season, they can regrow them. So if a predator grabs for a bird, it may just get a mouthful of tail feathers. The bird then flies away unharmed and begins to grow a new tail.
