Silver Spangle Cockatiels or the Spangle Cockatiel
or Edged Dilute Mutation is a colour that has been around for quite
some time. It was first discovered in Australia over 20 years ago but its
popularity has been minimal. Question has arisen as to the fertility of
visually spangle hens over the years but breeders have different opinions on
this. Some breeders have claimed to have successfully bred from visual spangle
hens of late but at this stage I have not been able to prove or disprove this
from my own breeding efforts. I believe that the spangles popularity has been
reduced due to significant inbreeding in the early stages and as a result it
has only been dedicated breeders that have been prepared to outcross these
birds that have kept the mutation going. At present I am working with 2
unrelated visual males and some nice big normal grey hens to hopefully
increase the size and vigour of the mutation. The resultant offspring will
hopefully give some good size split spangle birds to boost the quality in next
years breeding season.
Click on each picture to see enlarged size
Edged Dilute Mutation
Edged Dilute is the correct name of the genetic change
that has occurred to produce this colour cockatiel. Spangle is the term
that refers to the colour that is produced by the Edged Dilute change. The term
Silver has been added to the colour name because of the lighter grey colouration
produced. It does not mean that these birds will produce any normal pastelsilver
or west coast silver offspring if mated with a hen of those colours. It is
possible to produce a multi-mutation bird that is a pastelsilver spangle for
example, but at this stage I am only dealing with the single mutation.
The Edged Dilute mutation acts on the bird by reducing
the amount of melanin pigment produced. This reduction does not occur on an even
overall scale in the feathers and because of the unevenness the effect is that
of spangles or striations on the feathers. The longer flight feathers are the
mot obvious in showing the melanin that has been retained by the darker ends
still visible. In this picture of the back feathers on a 6 week old baby spangle
cockatiel you can see the obvious unevenness of the melanin reduction, shown
here as darker spangles or striations on each individual feather. The Spangle
pattern usually is darker on the shoulders and the head area.
On hatching the chicks appear to have a dark brown eye rather
than black but these appear to change to the normal dark coloured eye as seen in
normal grey cockatiels once the bird matures. The legs, feet and beak are all
seems to be some difference to the usual feather patterning on very young chicks
at pin feather stage compared to normal greys. I have noticed on Spangle
cockatiel chicks there seems to be a less noticeable white wingbar visible on
the pins (picture left) and upon opening of the feathers the flights have had no
spots on the underside as one would normally see in other mutations. I cannot
say that this is a characteristic of this mutation as I have only studied my own
birds but these traits have been the same on each one.
Genetics and Heredity
The Edged dilute mutation that gives us these gorgeous
Australian Spangle cockatiels is a result of the actions of an autosomal recessive
gene. This means that the gene is inherited in the same manner as pied or
whiteface or any other of the usual recessive mutations. To get a visual Spangle
cockatiel a bird must carry 2 Edged Dilute genes, one it receives from its
mother and the other from its father. A bird carrying only 1 gene will not show
any visual signs of the mutation but will be able to produce Spangle chicks if
paired with another bird carrying the Edged Dilute gene.
By far the
nicest cockatiels I have seen of this
have been the Whiteface Spangles (pictured right).
The variegated charcoal colouring interspersed with the lighter silver or white
feather colour give the bird a dusty or smokey appearance. The white face on the
adult males is striking when surrounded by this hazy patterning.
Another multimutation is the Pied
Spangle (pictured left). I have not seen many but the one I did have was a nice
sized bird. I found the pied effect seemed to take away most of the Spangling
except for on the shoulder area. This combination to me is not advisable as
there seems to be no point to deleting the spangles by adding the pied gene when
in effect the aim in breeding spangles is to promote their gorgeous pattern.
I currently have 2 unrelated clutches of juveniles from
Smokey, the whiteface spangle, and my other male Bo Jangles, a normal Spangle.
All Juveniles are normal grey split to spangle and whiteface so I am hoping to
add to my aviaries next year a lot more babies in the Whiteface Spangle.