And the most noticeable differences lie in the plumage... that is, the feathers. Not just in the different colours and patterns either. There are other, more structural differences. Now you might think that a feather is a feather is a feather, but when it comes to chickens this just ain't so! So let's look at what makes up feathers and how different genetic factors can alter the basics to give us all the wonderfully different chickens we have today.

Firstly, let us look at what feathers actually do. They provide the bird with protection from the elements, weather-proofing and maintaining body temperature. They allow the bird to fly, therefore offering protection from predators and other danger and they provide the means to attract the opposite sex. So how many feathers does a chicken actually have? Studies have indicated each grown chicken carries in excess of 5000 feathers, with some reports putting the number at closer to 7000, (though hard-feathered breeds such as Malay Games which have large bare patches on their bodies, obviously carry less feathers than say, a soft-feathered bird like a Cochin which carries profuse feathering). And of these thousands of feathers, there is a wide variation of shapes and sizes, depending on the functions they fulfill. Feathers which cover and help mould the shape of the bird are called tetrices. Those which are softest and closest to the skin are plumule feathers and those on the tail and wings which provide flight abilities are called quill or flight feathers. There is one further type, known as filoplume, which are hair-like and lie close to the skin. It is not known what function these provide.

Most feathers consist of the following parts. The quill is the hard stem which actually joins the feather to the bird's skin. This extends into the rachis (or shaft). Extending out from the shaft close to the base is the fluff. Further along the shaft comes the web which is the main surface of the feather. The edge of the web is called the vane. The web consists of branch-like barbs which in turn are lined with barbules and troughs. These interlock preventing air from passing through, while still allowing the feather to remain flexible. It works in a similar fashion to the fly zipper of your favourite jeans! The barbules and troughs are easily separated creating breaks in the feather vane, the bird repairs these breaks by running its beak along the separation and rejoining them just like a zipper. This is partly what chickens do when they preen themselves. However, not all breeds of chickens have these conventional feathers.

Silkies have a unique feather structure which gives them a fluffy "hairy" appearance. Normal feather structure is caused by the 'H' gene, however Silkies carry a recessive 'h' gene which is not present in other breeds of fowls. This results in the barbules being elongated and lacking the conformation required to hook together. It is this 'h' gene which gives the Silkie its strange woolly appearance.

Another breed with distinctively different plumage is the Frizzle. These birds have recurved feather shafts which makes the birds appear as if they have been put backwards through a wind tunnel! The feathers all curve toward the head. It is caused by an incompletely indominant gene 'F' and dependant on the influences of one of three recessive modifying genes. This means there are three distinct types of frizzling. The first of these gives extreme curling with narrow, weak feathers and a woolly appearance. The second gives less extreme curling, longer feathers of stronger structure (these are the exhibition type Frizzles). The last group display no frizzling at all yet these are valuable as breeding stock, useful for improving feather length and quality.