Birds are famous for their wings.
But did you know their tails are just as important for smooth flying?
And tails come in way more shapes and sizes.
Let's learn how birds use their tail feathers.
Tails are generally triangles of feathers at the back of a bird.
The triangle shape is like a fighter jet's wings.
So the tail can be thought of as a second set of wings that provide extra lift and control.
Tails have three basic functions for flying:
Extra lift during slow flight - aka smooth landings
Stability - aka keeping the bird from yawing, rolling, pitching, or otherwise losing control
Enhancing Wing Function - aka keeping the bird way up in the sky
Let's look at these three functions in actual birds.
Tails provide extra lift during takeoff and landing.
Let's look at this video of a bird taking off.
It's using its tail for lift.
When a bird takes off it folds its tail downwards and spreads out the feathers as wide as they
can go.
As the bird flies forwards air hits the tail and is pushed down.
This provides extra lifting capacity to get the bird up in the air.
In fact, up to 30% of the bird's total lift comes from the tail, with the rest coming
from the wings.
That extra lift from the tail also provides stability.
When a bird extends its wings its center of lift moves forward.
This is unstable, and without help the bird would fall over backwards.
But a tail can chip in some lift at the back of the bird, which keeps the whole bird stable.
Same thing during slow flight and landing.
The tail is folded down to stabilize and keep the bird up in the air for a nice, controlled
descent.
And finally, enhancing wings.
As the bird flies forwards air is pushed upwards by the tail.
That upwards-moving air also pushes up the back of each wing.
Using the tail this way makes the bird slower, but gives it more lift while flying.
Those are the general uses for tails.
Now let's look at specific tail designs to see how birds actually use them.
Performance Tails
Some birds just want to fly fast and turn faster.
Birds that eat flying insects are an example.
Like swifts and swallows.
They want to fly fast, so they can explore lots of air, and at random times they also
need to adjust course quickly to catch food.
Their whole survival strategy is to fly efficiently and do fast maneuvers.
So these birds have tails which are optimized for performance.
The pinnacle of a tail for flying efficiency this: A triangle with a 120
degree leading edge, where the outer feathers are twice as long as the middle feathers.
Hey look at a swift tail.
That looks familiar.
It's an almost theoretically perfect performance tail.
The tail does create a small amount of drag that slows the bird down.
So performance birds will fold their tails out of the way during fast flight and fold out the tail during turns.
When it's folded up a performance tail will look like two thin tails, because the outer
feathers are longer than the inner feathers.
And look at a swallow's tail when it's folded.
If you see a forked tail on a bird, it's likely to be a very, very good flier.
Durable Tails
While birds with performance tails may appreciate the efficiency of a triangle or delta
tail, the fact of the matter is triangles are fragile.
Those outer feathers are completely unsupported. And they can be damaged as a bird flies past trees.
So birds that live in forests tend to have more rounded shapes to their tails.
Like this one.
The sub-optimal feathers are less efficient, but think about what a woodland bird has to
do.
It has to have maneuverability to fly between branches and sticks, but the feathers also
need to take a few hits.
So woodland birds will tend to have rounded tails.
If you see a bird with a round tail shape, it's probably one that flies around in plants.
Those tails can provide lots of turning and stopping power when a bird needs to slow down
quickly.
And the delicate outer feathers are gone.
These tails are more resilient to damage because they have sections that are less important
for flight.
Ornamental Tails
In fact, tails are much less sensitive to changes in their shape than wings are.
So wing shape tends to be consistent in a few broad categories.
But tails can have a lot more unusual adaptations and still be useful for flight.
Ornamental tails are MUCH more common than ornamental wings.
These tails are used for display, to attract or to warn.
Just look at this diversity of tail feathers.
Beautiful bird tails.
Big bird tails.
Big and beautiful bird tails.
Bird tails that make sounds.
Tails with dangly bits.
Tails that are 8 times longer than the bird itself.
Mystery Tails
Just in case you thought we had this all figured out, there are some tails that have COMPLETELY
different.
Woodpeckers use their tails for support as they drill into wood.
Spine-tailed swifts have these tiny tails that hardly do anything but support the bird
as it builds its nest.
The Wiretail has this tail, and nobody knows why.
And the Pintail Snipe has tail feathers that are large in the middle and small on the edges.
Again.
No idea.
I hope you learned something that solved a mystery for you.
We talked about why birds have tails, and saw some strong examples of tail shapes from
around the world.
This doesn't have to be the tail end of your bird learning.
You can watch whichever of these ornamental videos catches your eye.
And you can increase your bird knowledge performance by subscribing.
Thanks for stopping by this week to learn what makes Life awesome!