Postati: 25 giugno 2008 at 17:09 | IP Logged

A new mutation can be add to the long list of existing mutations in the Budgerigar: the blackface. According to the phenotype of this mutant, this name seems to be the most appropriate. Therefore the name blackface is proposed.
Where and when this mutation origionally was derived cannot be ascertained, but it is almost for sure that it was in the Netherlands. In any way, the blackface discussed here was discovered in The Netherlands.

The facts:
Mr. Van Dijk, a Budgerigar breeder from the Netherlands, discovered two blue cocks having black undulated masks and black striped markings at their abdomen, amongst a wide range of varieties at a bird-market. He decided to buy the birds to breed with them and find out if the trait was a modification or inheritable.
In the first year the cocks were mated to normal Australian grey hens. Out of these matings normal greys and skyblues were derived, cocks as well as hens. During the second year Mr. Van Dijk mated the young hens back to the original cocks. Only one mating - original blackface cock x F₁ (grey) hen - produced offspring from which a few were blackfaced.
After the second breeding season it was almost certain that the blackface mutation resides on an autosome and is recessive to the wildtype. The testmatings Mr. Van Dijk carried out so far, confirm this point of view. At this moment there are no indications that the mutation is linked to any other known mutation in the Budgerigar.
Mr. Van Dijk observed a much darker body colour as opposed to normal birds split blackface [2]. A blue blackface without darkfactor is showing a considerable darker blue colour as is seen in normal cobalt blue Budgerigars. In grey blackface speciments without darkfactor, a comparable darkening of the bodycolour is observed as opposed to normal grey birds. In green blackfaces the same phenomenon has been observed. By the way, all green blackfaces died. Only a few pictures are left. At this moment Mr. Van Dijk has one cinnamon-blackface, naturally with a brown mask and ditto striped markings on the abdomen.
It was told by Mr. Van Dijk that the first two cocks bought in 1992 must have had a common recessive pied ancestor, because several recessive pieds were found in the offspring. In the passed five years several younsters were bred with a small headspot suggesting they are split for recessive pied. Breeding blackfaces is, according to Van Dijk, not as easy as one would like [2].

For this new mutation the symbol bf is proposed, derived from the English name given to this mutation. The wildtype symbol is bf ⁺.

Possible matings:

1. blackface x blackface = 100% blackface

2. blackface x normal/blackface = 50% normals/blackface and 50% blackface

3. blackface x normal = 100% normal/blackface

4. normal/blackface x normal/blackface = 25% normals, 50% norm./blackface and 25% blackface

5. normal/blackface x normal = 50% normal and 50% normal/blackface

Matings 4 and 5 are not recommanded because one cannot see which youngsters are split blackface and which are not.

Expectations:
Breeding blackfaces is, according to Van Dijk, not very easy. His stock contains about twelve blackfaces and some split blackfaces and "maybe" splits. It will take some time for this mutation to establish and will become available to a wider range of breeders. That is understandable, but on the other hand risky because if a fatal disease affects this stock or another disaster takes place, there is a chance the mutation will disappear again.
On the long run, when sufficient birds are available, one could possibly achieve a smooth colour of the "mask" and body, and what to think of a fully coloured black belly-spot?
If this is indeed a possibillity we will have to wait to see what happens in the future.

Note from the MUTAVI Research and Advice Group:
This mutation could be a mutation of the MC1R-locus which is not fully understood nor described in aviculture. Therefore it is recommanded to carry out further testmatings. It is obviously a pigment distribution factor resulting in some kind of melanism [1,3,4]. We have not seen these birds alive and our latest information is that they are extinct.

Literature:

[1] Bruckner J.H., (1939)
    The Inheritance of Melanism in Pheasants
    Journal of Heredity Vol.30; pp.45-52

[2] Dijk v., (1998)
    Personal communication

[3] Moore J.W., Smyth J.R., (1971)
    Melanotic: Key to a Phenotipic Enigma in the Fowl
    Journ.of Heredity Vol.62; 215-219

[4] Sage B.L., (1962)
    Albinism and Melanism in Birds
    British Birds Vol.55 no.6; pp.201-225