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 (i.e., 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.