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The New Rare Mutations
By Darren Francisco, Genetics Advisor
Recently I’ve received a number of questions about some of the newer color
mutations and have decided to write a little bit about each. Pastel, yellowface,
dominant silver and olive/spangled were the most inquired about.
Pastel is a rather subtle, but attractive mutation that is rather
appropriately named. The pastel mutation can be combined with just about any
other mutation with some beautiful results. All of the pastel cockatiels I’ve
seen have looked just like their normal counterpart (ie., pastel pearl vs.
pearl, etc), but the yellows, oranges, browns and grays are softened a bit.
Hence the name, pastel.
A really beautiful bird was a pastel pearl recessive silver. Wow! Talk about
a very soft, subtly colored bird. This is a neat mutation that gives a sort of
facelift to the birds we’ve come to keep on a regular basis. A pastel lutino is
just the neatest canary yellow, and the pastel cinnamon really brings new life
to this otherwise muted brown color.
Genetically, pastel is unique in the cockatiel world; it is both dominant and
recessive at the same time. Specifically, the pastel gene is only dominant to
the whiteface gene. To produce a pastel, you must breed it to either another
pastel or to a whiteface. The pastel mutation is not sex-linked (like pearl,
cinnamon and others). It doesn’t matter whether the pastel is the male or the
female in the pair to produce pastel offspring. Chromosomes occur in pairs in
cockatiels. Because of this, a visual pastel must carry the pastel gene on one
chromosome and either the pastel gene or the whiteface gene on the other
chromosome. Depending on whether your bird is carrying the pastel gene once or
twice would determine how many pastels and how many whitefaces you will produce.
Most of the pastels I’ve encountered just carry the gene once; they are
pastels split to whiteface. When a bird such as this is mated to a visual
whiteface, about one-half of the chicks will be visual pastels (split whiteface)
and the other half will be regular whitefaces (no pastel genes). If you have a
pastel cockatiel carrying this trait on both chromosomes, then all of the
offspring will be pastels split to whiteface.
Yellowface is another recent mutation that has generated
some interest. While it’s a few years old, the yellowfaces haven’t really made a
splash on the scene, so to speak. I don’t know why. Personally, I think any of
the mutations can be attractive (provided they’re on the right bird). There have
been a relatively high number of new mutations in the past few years, so the
market is a bit flooded, so to speak, and I’m sure the economy of the past few
years has put a squeeze on all of our new bird budgets. Yellowface cockatiels
look pretty much like normals, except that the traditional orange cheek patch
has been changed to a golden-yellow.
Genetically, yellowfaces cockatiels are produced through the same sex-linked
mechanisms as lutinos, cinnamons and pearls. If you have a yellowface male
paired with a normal hen, all of the female chicks will be visual yellowfaces
and all of the male chicks will be split to yellowface. If you have a normal
male paired with a yellowface hen, then all of the chicks will be normal, and
all of the male chicks will be split to yellowface. If you pair a normal male
split yellowface to a normal hen, the about one-half of the female chicks will
be normal and one-half will be visual yellowfaces, while all of the male chicks
will be normal, half will carry the yellowface gene. This is the same color
gene-passing process for any sex-linked mutation.
Dominant Silver is a mutation that I’ve had no personal experience with,
so I’ll pass on information that has been given to me by a couple of individuals
who are producing the mutation. It is aptly named since it is dominant to other
mutations to produce a silver of sorts. These silvers look significantly
different from the recessive silvers we’ve all been admiring for years. The
birds can carry the dominant gene on one or both chromosomes, with the coloring
effect being more pronounced in double-factored birds (if the dominant silver
gene is carried on one chromosome, it is single-factored; if the gene carried on
both chromosomes, it is double-factored). In my opinion, the dominant silver
reaches it’s most beautiful as a whiteface double-factored bird.
Because this mutation is dominant, you can produce dominant silver cockatiels
with as little as one single-factored parent bird. The dominant gene is passed
randomly to chicks of either sex. Those who receive it will be a dominant
silver; those who do not will be normal. It is not possible for a bird to be
"split to dominant silver." I did have a breeder try to sell me a bird that was
"split to dominant silver," which told me he either didn’t know what he was
doing or he was trying to pull a fast one. Either way, he didn’t get my money
(and I still don’t own any birds with this mutation).
One thing I am not aware of is how dominant silver would interact with the
cinnamon or lutino mutations. With recessive silvers, cinnamon and lutino really
show through the silver and lessen its appearance. I don’t know whether or not
this is true with the dominant variety, however I suspect you wouldn’t find
introducing cinnamon and lutino desirable with the dominant silver trait. If any
breeders have experience with this I would appreciate a note or an email so I am
clear on the matter.
Olive or Spangled is the newest mutation I’ve seen. The coloration is
difficult to describe. It isn’t an especially attractive coloration (my
opinion), but it is quite different and that alone makes it intriguing. It’s
kind of a dull greenish-cinnamon that is rather drab. The olives I’ve seen
weren’t even or uniform in color; it was a somewhat mottled appearance. It is
quite a unique look – unlike anything else. I have also seen an olive-lutino. It
looked like a lutino with a strange washed over its back – not completely
unattractive. In fact, if I hadn’t have known, I would have assumed the bird was
some bizarre cinnamon-lutino. Personally, I think the mutation will reach its
potential when combined with either whiteface or pied or both.
Genetically, the olive gene is non-sex-linked and recessive, just like
whiteface and pied. That means you will need both parents to carry the gene in
order to produce any visual olives. How many olives you would get depends upon
whether each parent is a split or visual olive. For example, if both parents
were split to olive, about one-fourth of the chicks (either sex) would be
visually olive, about one-half would be split to olive and one-fourth would not
carry the gene at all. Any chicks that weren’t visual olives would have to be
test-bred in order to determine whether or not they were split. If one parent
were a visual olive and the other a split, then about one-half of their chicks
would be visual olives and the other half would be split to olive. Treat the
olive gene just like pied or whiteface and you will have no problem producing
and keeping track of your chicks.
Well, that’s a brief glimpse into some of the mutations that we don’t get to
see with much regularity. If you have a chance to look at any of these new
colors, take it. I’m not saying you should buy the first rare bird you see (or
any for that matter). But I do think it would be a good thing for everyone to be
exposed to all aspects of cockatiel life, if for no other reason that to just
know what’s going on out there.
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