Common features that make birds birds include laying eggs, having beaks, and being covered in feathers. But do all birds have feathers? Are there any exceptions or examples of featherless birds?
Join us as we take a look at plumage, molting patterns, and how birds care for their feathers. So let's get into it, do all birds have feathers?
All birds have feathers, even flightless birds which do not depend on streamlined wings to take to the skies. A bird’s plumage serves an important function in regulating a bird’s temperature, helps them to attract a mate, and (in most cases) allows for flight.
The young of many bird species are born naked, but develop their first set of flight feathers in the first weeks of life.
The number and size of feathers an adult bird has varies between species; however, for all birds, their plumage plays an important role from everything to foraging effectively, attracting a mate, staying warm in winter, keeping cool in extremely hot conditions, not getting waterlogged in heavy rain, and deterring predators.
Read on to find out more about whether all birds have the same types of feathers, and whether if a bird loses or damages its feathers, will they be replaced?
All birds have feathers to help them fly, keep warm and attract a mate
There are seven categories of feather, all with distinct purposes, structures, and locations on a bird’s body.
There are seven different categories of feather on a bird
Two of the main reasons for which birds have feathers are vital to their survival: keeping warm and flying.
Baby birds that are born without feathers are at risk of dying from exposure to the cold unless their parent bird continues to brood them until their own feathers develop.
In juvenile and adult birds, feathers play an important role in the thermoregulation of a bird’s body temperature. In cold weather, birds fluff up their feathers to trap air in the pockets between them, thereby preserving any body heat.
Feathers have a water-resistant coating, which keeps the birds dry and warm in wet weather. In warm temperatures, birds can rearrange their feathers to maximize heat loss, cooling themselves to a more manageable level.
Birds need feathers to fly; although bats and insects achieve flight without feathers, they are a very much necessary part of a birds’ physiology for taking off and remaining airborne.
An additional, but undeniably important, purpose of feathers is the role that a bird’s plumage plays in attracting a mate. In many species the males with the showiest, most impressive plumage during breeding season stand the strongest chance of finding a mate quickly.
Conversely, many birds depend on their plumage to ensure they do not stand out, but instead are well-camouflaged against their surroundings, making it harder for predators to spot them.
Being covered in feathers also protects a bird against injury, as the delicate layer of skin is cushioned.
Mandarin Ducks have a spectacular range of colored feathers
Even flightless birds have feathers, despite them not being necessary for them to fly. All birds that fly need feathers in order to take to the skies.
The only birds that may not have feathers are some newborn chicks in the initial period after hatching – but this is only temporary and their first set of feathers tend to come through within the first few days of life.
Birds are not always born with feathers, and it’s usual for their appearance to change rapidly in the first few weeks and months of life.
Birds that are born largely featherless and undeveloped are known as altricial. They may have some tufts of down, but no feathers are visible until several days later. Initial pin feathers develop beneath the down on the wings, and these gradually open into their first plumage of flight feathers.
In contrast, precocial birds are reasonably well developed when they are born, fully covered with dense down. Precocial species such as chickens, ducks, and geese are born with feathers, and although they are ready to walk, run and sometimes swim shortly after hatching, it usually takes a further 6 weeks or more before their feathers are developed enough to support flight.
Most songbird chicks hatch altricial. It usually takes a couple of days for their feathers to start developing (Chaffinch pictured)
This young Sandhill Crane chick is an example of a precocial chick
Birds spend several hours a day preening their feathers, using their beaks to groom themselves, and arranging their plumage for flight and insulation. By ensuring their feathers are in premium condition, a bird maximizes its chances for good health.
A bird’s uropygial gland, which secretes oil, is located at the base of its tail. This oil helps with waterproofing, and is spread to different feathers by the birds’ beak and in some cases its feet.
Dust baths are another grooming technique used by birds as a way of keeping their feathers in tip-top condition. While flapping around in dust may seem counter-productive, the dust actually soaks up any excess oil, which is then easier to shed in oily-dust form. Dust can also help eliminate any lice or dry skin.
Bathing in water is another way in which a bird can maintain its feathers, not only for cleanliness, but also to repair any damage to the keratin in the feather shaft and structure. Research shows that after soaking damaged feathers in water, any out-of-shape fibers were refreshed and regained their original shape.
Puffing preening it's feathers
Molting is a natural part of a bird’s life cycle, shedding worn out feathers and replacing them with brand new ones. This molt happens once a year for some species but more often in other cases. Feathers are made from keratin, which becomes weakened with wear from regular flight or damaged by contact with trees, bushes, or even the ground surface.
Gradually every feather will be replaced, and while this is happening, birds will often have a noticeably shabby, patchy appearance, as new, vibrant feathers grow into the gaps alongside the worn, faded feathers as they are being shed. Molting may take a while, especially when new flight feathers are growing in, and this may mean a bird is unable to fly for a brief period.
A blue jay going through molting
In breeding season, male birds of some species rely on their bright plumage to get noticed and be successful in attracting a mate. Later in the season, once a pair have bonded and a brood raised, it is not uncommon for males, particularly some species of duck, to migrate to molting grounds where they lose their bright plumage and acquire a duller set of feathers until it is time for them to breed again the following year.
Another benefit bright feathers may bring is the ability to scare off predators. One fine example of this is the male peacock, who displays his full
A striking Fiery-throated Hummingbird
The number of feathers a bird has varies from species to species.
Hummingbirds are thought to have the fewest feathers of any bird, with around 1,000 on a typical adult. At the opposite end of the scale are Tundra swans, which have over 25,000 feathers. Penguins have the densest covering of feathers, with up to 15 feathers per sq cm (100 per sq in), with one Emperor penguin counted to have had 80,000 feathers.
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