do birds have smooth skin

The integumentary system consists of the skin, the feathers and the appendages (claws and beak). The skin covers the majority of the body and contains glands in the outer ear canal and the preen gland at the base of the tail, that the bird uses to preen its feathers. The integumentary system is very important in providing protection to the bird from a number of potentially dangerous situations. The functions provided by the integumentary system include:

BARE SKIN AND EPIDERMAL OUTGROWTHS

The avian integument undergoes numerous regional modifications or transformations. A spectrum of conditions can result in bare, non-scaly skin, from thin, sparsely feathered skin lacking any particular color to bare, colorful, extravagant outgrowths. The thickened integument in between can be plain or vividly colored, sparsely bristly or bare. Such altered skin is found mostly on the head, where it can be thick and covered in tubercles, as in guineafowl, vultures, colies (Colius), and many storks, ibises, spoonbills, and cranes, or it can be smooth, as in rockfowl (Picathartes). It may extend just around or beyond the eyes, e. g. bare-eyes (Phlegopsis), lyrebirds (Menura), helmet-shrikes (Prionops), cariamas, falcons, sheathbills (Chionis), parrots, cuckoos, broadbills, or around the corner of the mouth, as in gulls It is common to refer to the thickenings and projections as “fleshy” structures, but this term is misleading because “flesh” actually refers to muscle or fat, which they typically lack.

Almost always, these alterations or outgrowths are most noticeable on the head or neck. Typically, outgrowths of a species are bigger, brighter, or exclusive to adult males. Their coloring, which frequently differs from the surrounding plumage, is caused by blood in the superficial capillary network, intrinsic pigments, or structural mechanisms in the epidermis (Lucas, 1970; Prum et al. , 1994).

Adult birds have bare spots and outgrowths that grow with age; in young birds, these features are absent or very primitive. Certain ibises and storks are among the species whose juvenile feathered areas eventually become bare, losing both feather follicles and feathers. These regions’ epidermis exhibits a significant level of lipoid secretion (personal communication, G K. Menon). The integumentary structures formed by adults are typically permanent, though they may change in size or color depending on the bird’s reproductive activity.

Skin of the feathered areas

Because the feathers typically cover the skin, it is normally protected and therefore thinner. Compared to the rest of the body, the skin over the wings and thighs is more tightly attached to underlying tissue. The thickness of the epidermis is approximately 12 cells, with approximately 5 cells in the horny outer layer, 2 cells in the transitional layer, and 4-6 cells in the inner, germinative layer.

Feather growth

When feather growth begins and when down is replaced, it is determined by sex-linked genes. It is more accurate to refer to a chicken’s feathering as early or late rather than fast or slow. The moulting of feathers in close proximity is regulated locally by something, possibly a hormone. Each pterylum (pterylae) in a wild bird has a growth center that provides an ordered sequence for the typical moult. In poultry, this control is less noticeable even though the proximal flight feathers moult first.

There is also a degree of control between pterylae. An essential characteristic of flying birds is the synchronized moulting of bilaterally symmetrical pterylae. The pterylae sequence begins with the feathers on the wings, moves down the body, and terminates at the head and neck. In fowls, the moult is a seasonal occurrence in autumn. However, environmental conditions may initiate a moult at other times. When stressed, fowl in good production are prone to moult. Males moult before females.

Thyroxine, the thyroid gland’s hormone, increases the metabolic activity of the cells that form feathers, which is important for feather growth, differentiation, and patterning. Thyroxine has no effect on chicken down; only the feathers of juveniles and adults are reliant on sufficient quantities being accessible. The growth of feathers on wings is independent of other factors, and in adults, all feather growth stops except on the wings following thyroid gland removal. By accelerating the anagen phase, thyroxine induces a moult, with females being more sensitive than males.

FAQ

What is the skin texture of a bird?

Avian integument is thin, elastic, and loosely attached to the body, giving birds the freedom of movement needed for flight. Its epidermis is both keratinized and lipogenic, and the skin as a whole acts as a sebaceous secretory organ.

What kind of skin do bird have?

Birds have a thin and delicate epidermis, or skin, compared to other vertebrates. Their skin produces specialized structures called feathers, which is one of the unique characteristics of birds. Feathers are made up of keratin, a flexible protein that also forms the hair and fingernails of mammals.

Do birds have scales or scaly skin?

In birds, there are two major integument appendages: scales on the foot and feathers on most of the rest of the body [2••]. Scales provide protection and prevent water loss.

How is your skin different than a bird?

Bird skin is made to hold feathers. Human skin is thicker and stretchier and can only grow hair follicles.