Bird Feathers (Structure, Types, Uses & Fun Facts)
Disclosure: Some links may be affiliate links. If you buy an item via links on our site, we may earn a commission. Learn more.
Birds are unique in many ways but did you know that they are the only group of animals that have feathers? Well, today at least; there were some dinosaur species that had feathers.
Feathers are a special adaptation in birds and come in a wide range of shapes, sizes, and colors. Each type of feather has its own unique job.
In this detailed guide to bird feathers, we’ll explore the various types, why birds have them, feather anatomy, and much more.
Bird Feather Structure
Feathers are made from the same protein as human nails and hair; this is called keratin. It’s also the same material that their beaks are made from and is incredibly strong.
While feathers do come in a variety of shapes and sizes, they all have some features in common. Interestingly, individual feathers are incredibly light, but when combined, they could make up most of the bird’s weight.
Let’s take a look at the structure of a bird feather.
Barb
Each bird feather can have hundreds of barbs which are filament-like structures protruding from the rachis (more on that later).
The bards point in an outward diagonal direction towards the tip of the feather and are arranged parallel on either side of the rachis.
Some describe the barbs as being similar to the branches of a tree and they hook together to form the vane.
Barbule
The barbules extend from the barbs and are small hair-like structures. They are held together by barbicels which are even smaller structures that act in a similar way to Velcro, hooking the barbules together.
Rachis
The rachis is the main structure of the feather and is a long shaft that sits in the center from which the barbs grow. The rachis supports the entire structure of the feather.
Calamus
You’ll sometimes hear this part of the feather being called the quill, but whatever name it goes by, the calamus is the bottom part of the rachis which is hollow and whose main job is to anchor the feather. Unlike the rachis, it provides no structural support to the barbs.
Vane
The vane is the name for the flat surface of the feather at either side of the rachis. This is made up from the barbs and barbules.
Types of Bird Feathers
Birds have various different types of feathers, each one designed to do a different job and aid the bird in various ways. Let’s explore the types of bird feathers in a little more detail.
Wing Feathers
Wing feathers, also called flight feathers, are located on the wings and the tail. These feathers have a windproof vane, of which one side is wider than the other. Compared to other types of feathers, the flight feathers are also considerably longer.
The barbules of the wing feathers are a lot more robust as additional strength is needed when the bird is in flight. The leading edge is not as flexible, and this prevents the feathers from twisting during flight.
Tail Feathers
The tail feathers are very similar in their structure to the wing feathers. However, the main purpose of the tail feathers is to aid the bird in steering when it is flying; the fan-shaped arrangement helps with this also.
Most bird species have six pairs of tail feathers on either side. However, there are some species that have evolved to have much greater plumage in this area, largely for mating rituals and displays.
Contour Feathers
At the base of the contour feathers, the bird is provided with extra insulation. However, these feathers also provide the color of the bird. They’re among the most prominent on its body but are not on the feet, legs, or beak.
Contour feathers come in a range of colors that are uniquely beneficial to the bird. Typically only colored at the tip, some are made for showy displays, whereas others are very bland and help the bird to camouflage.
Semiplume Feathers
In the main, semiplume feathers are located underneath the contour feathers and provide additional insulation for the bird. However, there are some that are elongated and used in mating rituals. While these feathers are not as well formed as contour feathers, they’re considerably more structured than down feathers. The underdeveloped barbicels mean that the semiplumes are much softer.
Down Feathers
Down feathers are among some of the smallest of all feathers and are noticeably fluffier. These feathers’ main purpose is insulation. However, there are some birds whose down feathers turn into a powder which the bird can then spread over themselves as a waterproof layer. This is largely seen in aquatic birds such as the heron.
These feathers are much closer to the bird’s body in order to better retain heat and unlike other feathers, they have a very small, or no rachis. The barb structure is also much looser.
Filoplume Feathers
Filoplumes are sensory feathers that act in a similar way to whiskers on mammals. They allow the bird to detect the position of its contour feathers and, for this reason, only have a few barbs concentrated at the tip.
Other types of bird feathers are attached to muscles but the filoplume feathers connect to nerve endings. They direct messages to the brain and can tell the bird everything from the position of other feathers to wind speed and much more.
Bristle Feathers
Some birds have bristle feathers around the mouth, primarily those that feed on insects. They use these feathers to funnel their food into their beak. There are also birds that have them around the eyes and, in this case, they work the same as human eyelashes, protecting the eyes from debris.
Bristle feathers are much sparser and stiffer than other types, and the barbs are largely located at the base.
What Use are Feathers for Birds?
Feathers have a lot of uses and without them, birds simply wouldn’t survive. From keeping them concealed from predators to attracting a mate, providing them with insulation and protection to aiding their senses, these are essential parts of the bird’s anatomy.
Protection Against the Elements
Just like mammals have fur to keep them warm, birds’ feathers act as a source of insulation. What’s truly amazing is that some bird species, particularly those that live in colder climates, will shed feathers in the summer and gain more when winter comes around.
As well as keeping the bird warm, feathers also protect them in hot weather by helping to regulate their body temperature and keeping them cool.
Birds spend a lot of time out in the open, and this means they have to face rain, snow, and other forms of precipitation. Not to mention that some birds spend a lot of time in bodies of water. But feathers act as a waterproof barrier, keeping the bird dry. There is one exception to this; the anhinga, sometimes called the water turkey, who actually has to dry itself after bathing.
You may have heard the saying like water off a duck’s back and this comes from the fact that the coated contour feathers allow water to literally roll off!
The feathers will also help to protect the bird against other types of external dangers, such as tree branches. Without them, birds flying into trees could sustain cuts to the skin. Moreover, feathers provide a layer of protection against mites and parasites. This is particularly true of birds with powder down which can be used to control mites.
Camouflage
Whether they need to hide from predators or camouflage themselves to be stealthy when catching prey, some birds have feathers that help them to blend in.
For example, the snowy owl has beautiful white feathers that help it to blend into the snowy backdrop of its habitat. Other types of owls have brownish feathers that help them to blend in with the bark of trees.
Display
Many birds have colorful feathers that they use for communication. In order to do this, they need to create bright displays. For example, the blue jay is well known for its call but it also has a crest of feathers on top of its head which the bird moves depending on what he is trying to say. The feathers may slick back when they’re nesting but they’ll raise when they’re trying to communicate something.
You may notice similar behavior in one of the most common garden birds in the US, the northern cardinal. They have crested heads, which they display for communication, but even birds without a crown may move or puff up their feathers to relay a message.
Attracting a Mate
Feathers can be an excellent way to attract a mate since some are incredibly bright and colorful. It’s mostly male birds that have bright plumage, and you’ll notice that females can seem very dull in comparison.
Perhaps the most well-known male bird to use its feathers in a courtship display is the peacock. His long, patterned, and brightly colored tail feathers extend upwards and outwards behind him in an attempt to attract a female.
Flight
Not all bird species can fly, there are around 60 flightless species. But among the majority that can fly, feathers play an important role in transportation. The bird’s contour feathers make them more streamlined, so it’s easier to move through the air.
They also have long wing and tail feathers that aid the bird in propelling through the air. These flight feathers are strongly anchored to the bones and have incredibly strong ligaments because flying is a demanding activity.
Birds also have secondary flight feathers which provide additional lift even though they cannot be independently moved.
How Did Birds Evolve to Have Feathers?
It’s hard to imagine a bird without feathers but these creatures didn’t always look the same as they do today. In fact, feathers are something that evolved over time, so let’s go back and see how and why that happened.
It’s been discovered that there were feather-covered animals as far as 150-200 million years ago, and surprisingly, birds weren’t the first to don these unique body coverings. As a matter of fact, new research has shown that feathers came along well before the birds we are familiar with today. It was actually bird-like dinosaurs that had the first feathers, such as the archeopteryx fossil found in the mid-1800s in Germany.
But even so, the feathers on these creatures are thought not to be the most primal. It’s been discovered that the first feathers were nothing more than hollow tubes which slowly evolved into small clusters. These clusters further evolved with the development of barbules before eventually forming a structure that more closely resembled the flight feathers of modern birds.
At this point, the evolution of the hooks that create vanes continued but scientists are still unsure how flight truly came about with theories that support both the idea of gliding and a running terrestrial animal. But one thing they are sure of is that many dinosaurs had feather-like coverings including the T-Rex. While these were likely intended for insulation, the clear evolution of feathers means that the modern relatives of these ancient creatures now have the ability to fly.
Feather Colors
Bird feathers come in almost every color imaginable. There are those that have very dull and drab feathers for camouflage, whereas others are so brightly colored, one feels as though sunglasses are needed!
The color of the bird’s feathers is determined by pigments. These pigments are either made by the bird itself or come from the food it eats. There are three types of pigment responsible for bird colorings which include:
- Melanin
- Carotenoids
- Porphyrins
For example, flamingos are not pink when they’re born, but their diet of algae and shrimp causes their feathers to change color.
This is also true of birds that have red or yellow plumage; the saying you are what you eat could not be more accurate.
However, it has long baffled scientists as to why some bird species have green and blue feathers, as this cannot come from their diet. Any blue pigments in food are broken down by the digestive system, so cannot emerge as color in the feathers.
But it’s now known that these colors are a result of refraction; light bouncing off the feathers giving the illusion of color. While red and yellow light are able to pass through the atmosphere owing to their longer wavelengths, the shorter blue waves just bounce off whatever they hit.
Did you also know that the color of a bird’s feathers determines how strong they are? The darker the feathers, the more robust they are. For example, white feathers are incredibly brittle whereas black are the strongest. This is because of the presence of melanin in the feathers; the more melanin there is, the darker the color.
But melanin is also a type of strengthener, so the more there is, the stronger the feathers. This is why you’ll often see at least some black on a bird’s flight feathers which need to be very durable.
Why do Birds Fluff their Feathers?
You’ve probably seen birds in your backyard during the winter all puffed up like little baubles. But they’re not doing this with a mind of appearing cute; birds fluff their feathers to keep warm.
In summer, birds tend to keep their feathers very close to their body as this sends out any insulating air, helping them to stay cool.
But in the winter, they puff up their feathers which traps air between them that is warmed by their body heat, helping the bird to stay warm. Couple this behavior with those soft downy feathers near the bird’s skin and it’s a pretty effective system to keep cozy!
Why Do Birds Preen Themselves?
Preening is a word used to describe the way that birds maintain their feathers. This is something, when we observe avian species, can be seen often, and that’s because it’s so important. It’s thought that birds spend up to 25% of their time preening because, if they didn’t, their feathers would not work as intended.
Why Do Birds Need To Preen?
Preening involves many different aspects but the main aim is to reposition the feathers so they are most effective. If birds did not preen, this could be a threat to their survival. Moreover, if you look at the preening habits of captive birds, these are vastly different to wild birds with a role model. While birds are born knowing the basics of preening, much of it is learned behavior.
Birds that do not preen would have feathers that were badly placed and this would affect their ability to fly.
What’s more, preening ensures that the barbs are in uniform rows and this creates an airtight surface. The bird does this in order to ensure the feathers properly insulate it. With the feathers properly aligned, the bird also improves their waterproof abilities.
Birds, like many other animals, are prone to mites but preening with their beaks allows them to remove pests and parasites. You might even see bonded pairs preening one another to remove mites and as a sign of affection.
And speaking of bonds, birds will preen themselves to ensure their feathers remain attractive looking for when it’s time to seek out a mate.
Preen Oil
When birds preen themselves, they secrete a special substance called preen oil which they use to coat and protect their feathers. This oil also adds a waterproof layer to the feathers.
Preen oil also ensures that the feathers remain hydrated and moisturized. If they weren’t, then they would become brittle and be at risk of breaking.
Although, there are some species of birds that do not have the glands under their skin to produce this oil. It is these species that rely on powder down instead.
How Do Birds Preen?
The main way that birds preen themselves is to move the feathers and rearrange the barbules so that they can perform optimally. They do this using their beaks, although this isn’t the only thing they’ll do to ensure their feathers are well maintained.
They may also combine preening with sitting in the sun and ‘sunbathing’ which can be beneficial in keeping mites at bay. This behavior has also been noticed in birds after rain and is thought to be used as a way to dry the feathers.
Some birds will bathe in dust as a way to dislodge parasites from their feathers, while others will take a dip in a body of water before performing preening with their beaks. The dust will also soak up any extra preen oil because you can have too much of a good thing!
When a bird is preening, you may see it stretching. The reason for this is that the stretch allows space to form between feathers which makes it easier for the bird to rearrange the barbs and make everything flat.
Finally, some birds have a very unusual way of maintaining their feathers, and they do this with the help of ants. The action is known as anting, and sees the bird rubbing itself on an ant’s nest. These insects are covered in formic acid which, when rubbed onto the bird, can act as a pest deterrent.
