Abstract
In the 1976 April-May issue of the A.F.A. "Watchbird", I wrote an article on the beautiful little aviary gems (Neopsephotus bourkii) or (Neophema bourkii).
In the previous article, I stated that the yellow mutation was sex linked, as are most red eyed mutations. This information had been passed along to me from breeders in Holland.
I can now state positively that the species I am raising are not sex linked,but are a recessive type mutation.
In my aviaries, a yellow cock was mated to a normal hen, and from this mating, no yellow babies were hatched. About half of the normal colored babies were cocks, and the other half were normal colored hens, proven by the fact that they laid eggs. These results proved that the yellow male's mutation was not sex linked.
I mus.t confess I was very pleased to discover my previous statement was erroneous, as I now know that both cocks and hens can be split to yellow.
The new mating expectation theoretically are as follows:
1. Yellow cock x normal hen= all babies are normal in color, split to yellow.
2. Yellow hen x normal cock = same as step 1 above.
3. Yellow cock x split/yellow hen = 25% yellow cocks, 25% yellow hens, 25% split/yellow cocks, and 25% split/yellow hens.
4. Yellow hen x split/yellow cock= same as step 3 above.
5. Split to yellow cock x split to yellow hen = 25% yellow babies, either sex, 50% split/yellow babies, either sex, and 25% normal Bourke babies, either sex.
This mating I don't like, as split babies can only be determined by test breeding, sometimes requiring two years or possibly more.
6. Split/yellow male x normal hen, or split/yellow hen x normal cock = No yellow babies, 25% split yellow babies, and 75% normal babies.
As you can see, this mating is even less desirable than step 5.
In the previous article I mentioned that yellow cock x yellow hen proved to be a very weak mating with a lot of dead in shell embryos. However, in the future I shall attempt several more of these matings just to satisfy myself that this mating combination is really undesirable.
The latest report I received from Europe was that there are three different mutations of the yellow Bourke, one of which is sex linked, and two of which are recessive.
In the meantime I suggest that if you acquire the yellow mutation Bourke parakeet, treat it as a recessive mutation, using suggested matings in steps 1, 2, 3, and 4.
In the past breeding season, two yellow hens mated to split males, and one yellow male mated to a normal hen (3 pairs in all), producing 34 babies, 3 clutches each, one pair 14 babies, one pair 13 babies, and one pair 7 babies. You can readily...