An anonymous Bourke
This Bourke parrot was bred out of a combination of an edged cock ( Dutch: gezoomd), split to pastel and a lutino hen, split to pastel. This combination gave wild type and pastel cocks and hens also. The breeder asks:
1. What would be an acceptable explanation of the change of colour in this Bourke?
2. Is it a new variety? If so, what name would be appropriate? Or is it maybe a variation of a already known variety? If so, which variety?
I want to add a third question:
3. Do you know maybe this variety by own experience? If so, what were the parents of this variety?
To get answers I want to ask the group of breeders of the Bourke's parrot. It would be very nice if somebody could find an acceptable explanation. In the following update of this page I will mention all suggestions. Also I will mention the name of the owner. of this Bourke. I would appreciate to send your reaction to: firstname.lastname@example.org
Breeder: This Bourke was breeded by Hennie Ebbekink (Holland).
Parents: This Bourke has an Edged wildtype father, split to pastel and a lutino mother, split to pastel. Also from this combination mr. Ebbekink bred pastel hens and cocks and wild type Bourke's.
Description: A careful inspection of the plumage shows a little loss of brown eumelanin in wings- and tail feathers. This regards the flights, greater upper wing coverts and long tail feathers. The outer wing feathers have one brown and one blue vane. Both vanes of each feather did loose some melanin. In both vanes we see some sort of striping. There is no altering of the blue structure of the feathers. The blue structure cannot express him selve when the melanin fails. We see this striping in the brown and blue parts of the outer wing feathers and the tail feathers.
Is it a new mutation? It is to early to conclude that there was a new mutation that caused this colour variety. We have to wait for breeding results with this young Bourke. Maybe this colour variety is inheriting, maybe not. When there are more equal looking breeding results reported, the possibility that it is a mutation increases. This variety is not wide spread among in the aviculture in Holland. Only one other case is reported. I got pictures from this fancier. He bought two young Bourke's with the same marks. I respect his request not to give further information.
Is it a grey mutation? In this case it is needed to make difference between the colour description and the mutation factor of this Bourke. This Bourke is called grey wing. because the wing colour is lighter than normal. This is a common name. It can not be a grey mutation factor. The grey factor affects the blue structure of the barbs. If it is a mutation it will be a melanin mutation. There is not an equal loss of melanin in the whole plumage. It is a loss of melanin in the brown and blue vanes of the primaries and long tail feathers. Also the greater wing coverts did lose some melanin. The remnant of melanin is brown. We suppose that there is no altering of the melanin granules.
There were no other suggestions than grey wing. My suggestion is that maybe there is a connection with the Edged wildtype Bourke variety. Breeders of the Edged Bourke discovered that the Edged (gezoomde) Bourke does not follows the rules of a recessive inheritance. There are less Edged young Bourke's in the offspring of Edged parents than expected. It could be possible that there are two factors that come together in the Edged, a recessive melanin mutation factor and a dominant melanin mutation factor. The father of this Bourke is an Edged wildtype. The massive loss of melanin in the strong edged Bourke could be the result of two factors. One recessive and one dominant factor.The fine striping in the wings and tail of this young Bourke could be the result of the dominant melanin factor.
Conclusion: We have to wait for more breeding results. There is no grey mutation factor. The reduction of the eumelanin is not equal in the whole plumage. Maybe there is a link to the Edged wildtype Bourke. This is a hypothesis, that has to be proved in the future.