Are Splits "the Pits"?

Abstract

(While this article i'> written <pccifically in terms of Cockaticls. it applic-, a' well to the breeding of most species of birds that involve rnutations.)

First let me define the term ··.,rlih · ". It i" a bird that usually appear- to be one coloration (a Normal or a mutation). but because of it"., heredity .. carric-. a hidden gene for another t) re. He or vhe i' literal I) "<plit " genetically The bird is one half what he or xhe looks like. and one half an entire I) different color (mutation l. Thi'> masked half is hidden in Normal split'> (example: a Normal colored bird split to Pearl) because Normal is dominant mer the recessive mutant gene (in this case:

Pearl). Thi'> is written: X X"' On mutant split!'> (for instance: a Pearl split to Lutino). it is not a matter of Pearl being dominant 0\ er Lutino: but because both color genes carry Pearl. and only .one carries Lutino - written: X" X"1• In other words. a spl it is a bird that carries a mutant factor only on one of the two genes. Again. we are talking Cockticls. where to Ill) know ledge. we do not ) et have an; mutation that i'> dominant O\ er another. In some specie'> of

 

birds. there i'> thi, added cornplcxiry .

B) now . half the reader' have quick ly skipped on to the next article. Genetic'> turn many people off. It all •.. ound- too complex and to throw in a fe\\ chartx w ith xs. y·,. p·,. & o· v. is enough lih.e hieroglyphic'> to discourage all hut King Tut. But genetic'> i'> like math. Yes. it can get com pie': but 90'( of us get through the grocer) vtore , the month I: billv. and barely through income ta-, forms. without an) know ledge of calculus. Sn ton can the J\cragc breeder function responsibly \\ ithout a college degree in Biolog , - just an undervtanding of the simple basics of gcnctics (audition. subtraction. multiplication and div ision). Like math. genetic- arc fixed and able to be calculated.

Ano 110\\ I w ill prompt I) drop UO\\ n to sc.~ of thi-, publicutions readers. bccau-,c Ill) purpose of thix article i' not to further explain or c xcmplify genetic'>. George Smithx book. ENCYCLOPEDIA OF COCKAT!ELS. ha' an c vccllcnt chapter on the subject. Ton; Barrett. from <outhern California. ha' a flair for making the

 

complex seem simple (and humorous) in two articles: The American Federation of Aviculrures "Watchbird " magazine (vol. V. no. 5. Oct/Nov. 1978): and "Bird World" magazine. June/July. 1978. In my forthcoming book. Rainer Erhart's chapter. which includes extensive charted calculations of all possible crosses, will hopefully prompt everyone to buy a copy for every bathroom in the house.

But why do people seemingly avoid using split birds"! I can only think of two possible reasons. First. as discussed above - fear of genetics. Secondly - greed: wanting to produce I 00</'c nests of mutations ..

I am not a believer in the old wives' tale that it is had to cross Lutino x Lutino , Pied x Pied. Pearl x Pearl. or Cinnamon x Cinnamon. These mutations have been around long enough that they have had years of outbreeding involved. Try it! If the young do not equal and hopefully surpass the quality of the parent birds. then change the pairings. I have had young from mutant x mutant matings that are better than chicks produced from Normal pairs or splits. and visa versa. I see no set rule indicated here. other than to test for potential and parental performance. judge the results.

The main beauty of splits is that they are

 

a way of including new blood without canceling out production of some mutant young in the first generation. They are also the less expensive route to go in breeding for a particular mutation. Also splits offer variety in the clutches so that a breeder will have a more versatile list to serve the buyer's needs. In the case of "double splits" (i.e .. birds split to two different mutations), they may be bred to a variety of mates and still produce both mutations plus split birds.

Using splits is also a way of combining certain features from one "line" with ideal aspects from another. For instance: perhaps your Lutinos have good size but lack the full crests of your Pearls. Wouldn't it be nice to end up with both your Lutinos and Pearls being large and full crested - and then as a bonus, produce an occasional combination LutinoPearl, all on one bird?

This brings us to the subject of crossmutations. which are becoming quite popular in the U.S. Across-mutation is a single bird that physically shows and genetically carries a combination of two (or more) mutations - a Pied-Pearl, Cinn.Pearl. Lutino-Pearl. etc. Each is not a new mutation: only a combination of existing mutations. These birds can be quite striking!

 

It takes a minimum of two years to produce from scratch a cross-mutation, and it can only be accomplished through the use of the "lowly" split. The novice will think that he can take a Cinn. to Pearl mating, and Bingo! Cinn.-Pearl young! Not that easy. The key is in the males from such a cross which will appear to be Normals, but will in fact be split to both Cinn. and Pearl (Xe XP). The following year this Normal/ Cinn. & Pearl is mated to either a Cinn. or Pearl hen. And even then there are eight possibilities of type young produced. Only one of these eight will be the crossmutation: Cinn-Pearl (in sex-linked mutations it will be a hen: (XcP Y).

At this point let me explain what "cross-over" is. Above we mention the Normal split to Cinn. & Pearl, written: X" XP. This means that usually one gene (Xe) carries the Cinn. factor, and the second gene (XP) holds the Pearl factor. Without going into the whys and hows, know that occasionally the Cinn. factor and Pearl factor combine on the same. gene (XCP) leaving the second gene as Normal (X): written xcP X. When this single x= combines with the female Y gene. the result is always a Cinn.-Pearl hen.

Remember we are also using the CinnPearl as an example. Lutino , Pied, and Fallow would also be interchangeable on

 

the male genes. However, on the Pied and Fallow mutations, being straight recessive, hens can also be split. (There is no such critter as a Normal hen being split to a sex-linked mutation.)

There has been some discussion of the frequency of "cross-over", which is necessary to produce a cross-mutation from this double split Normal male (N/C&P). A year or so ago I read that one out of thirty young could be a cross-mutation. While work on this double mutation bit is still in it's infancy, I think the odds arefar better than supposed. There have been too many instances where one or two crossmutations have turned up regularly in even single clutches.

Aside from the aim of producing your first cross-mutation bird, a secondary bonus is realized in the split chick that shows the coloration of one mutation and is split to another. In the example we are using, (Cinn x Pearl parents) this might be a young Cinnamon split to Pearl male - X" X'". Using this very valuable split bird means that we no longer have to rely on the whims of' 'cross-overs''. We always have two mutant factors on one or the other X genes. If that "P" factor should jump from the X on the right to the X on the left, it doesn't rnatterr X'" X" = X" X'"). Using this C/P male mated to either a Cinnamon, Pearl or Normal hen, will predictably produce 259t C-P hens.

But of even greater importance is that this C/P male when mated to a Cinn.-Pearl hen (preferably not his sister). will finally produce on a 1 :4 ratio. your first C-P male. (In sex-linked mutations, males are rarer, and prices often reflect this.)

Starting from scratch the first year with for instance a Cinn. male and Pearl hen (or visa versa) it will take a minimum of three years to produce a C-P male. and then only if suitable cross-overs have occurred in the second year. And note that we have only been able to achieve our final aim through the use of splits - twice.

 

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