To understand how truly important and unique the normal
grey cockatiel is it is important to understand the theory behind what is
called a 'mutation'. Normal Grey Cockatiels are what is referred to as
the 'Wild-type' Cockatiel colour. They are not a mutation.
Female and male
What is a mutation?
A colour mutation is a result of a malfunction or change of
an original gene which causes it to act differently and thus change the original
colour of what we would expect. The genes that give us any other colour that
differs from the normal grey bird are mutant genes. Each separate colour
mutation is in fact a result of only one gene that has mutated from the original
out of the thousands of genes that are found in any one individual. No-one can
give an exact reason why any particular gene changes from its original form and
acts differently but it occurs in the wild the same as it does in captivity.
Because of the process of natural selection in the wild often these new
mutations are never seen. In captivity we have the ability to selectively
propagate these individuals that are mutations and thus create larger numbers.
Normal Grey Cockatiels
Having now learnt what a mutation is it becomes apparent how
important the normal grey cockatiel is. Every gene within this bird is original
and working perfectly. There are no mutant genes present to alter the colour or
pattern from the original in any way. This is what makes this bird even more
valuable when we start breeding mutations. The normal grey has the perfect
original genes that can be used through breeding to strengthen the mutant
genes to give normal sized healthy birds of different colours.
The
normal grey cockbird is a dark grey almost black coloured bird with a yellow
face and bright orange cheekpatch. His main body feathers are solid coloured
dark grey with no signs of spots or stripes or barring. It is only when the bird
carries the pied gene or is split pied that any visual external variation is
noticeable. The bird in the picture on the left is split pied and can be
recognised because of the white patch of feathers on the back of his head. Some
say that the a whitish ring around the yellow face of the bird indicates he is
split to whiteface but I am not 100% certain this is true. This bird does have a
white ring around the yellow and he is split to whiteface so there may be some
truth to it.
The
normal grey hen bird is the same grey body colour as the cock but lacks the
bright yellow face. She still carries the normal cheekpatch but instead of the
face being yellow it remains grey with sometimes a slight yellow suffusion of
colour. The colour that she is when she first gets her feathers as a chick is
basically the colour she will remain. The cheekpatch gets more orange as she
ages but by about three months old she will look the same as she will as a
mature hen. The cock bird however is indistinguishable from the hen at hatching
but by six months when he moults he will have become obviously male. The picture
to the right is a juvenile photo of the same cock bird shown above. In
fact this bird was purchased at three months old as a hen.
A noticeable difference between the cock and hen bird apart
from the yellow face is the absence of tail barring and stripes that appears on
the hen. When the male goes through his first moult the new feathers he grows
will have no sign of any striping or bars. These traits are retained in the hen
and thus the normal grey cockatiel is referred to as Dimorphic. Sexual
Dimorphism means that there is a different feather colour or pattern for
hens and cockbirds of the same species. The yellow face on the males and the
lack of tail-barring are examples of this.