On request: article Agapornis roseicollis: DM Jade

New mutation in Agapornis roseicollis: DM Jade
(Article published in 2017 / update 2018)

By Dirk Van den Abeele
Ornitho-Genetics VZW
MUTAVI, Research & Advice Group

It has been nearly ten years since Miriam Bisiacchi told me she had a deviating colour in a number of her Agapornis roseicollis. These birds had all been born with red eyes which became darker after a few days, but the main problem was that all these birds also contained the marbled factor. The consequence of course was that it was difficult to predict what this deviating factor actually does. Of course, we always recommended Miriam, as always, to try to breed this mutation in the green base type. That is the only way to determine what this mutation entails.

This was a process which is not as easy as it might seem. It turned out that the marbled factor cannot be bred out quite that easily (can be an indication that both mutations – marbled and DM jade – are on the same chromosome and we need a crossing-over to separate them). In the meantime, the birds were paired with a number of other mutants, so as to be able to detect possible alleles. These types were for instance paired with pallid, cinnamon, etc. In each case green young were born which excluded alleles with these mutants. Eventually the first young in the *blue* series were born. Because we wanted to exclude the idea that these were ‘bad’ marbleds or alleles, they were again paired with marbled. This also again resulted in green young which excluded this avenue. In the meantime, feathers were examined, but these did not yield any conclusions.

Description.
In this mutation the green colour has been reduced. It is striking in these birds that they have a variable eumelanin reduction in their plumage. The wings seem more yellow green with a green hue. Whereas the wings have a visible eumelanin reduction of about 50%, the reduction on the body is a lot higher; there the feathers are more yellow with a darker hue. We know that the wings are always somewhat darker because on the wings eumelanin is present in the barbs, contrary to the feathers on the chest and abdomen, but in my opinion this does not explain the difference in colour. If we look closely, we see a random spread of a greater eumelanin reduction in the core of the wing coverts which could show a very slight edge. The flight feathers are strikingly yellow in the outer vane and have a nearly white inner vane surrounded by a light grey edge. In other words, the core of the inner vane is somewhat bleached. The rump has been severely bleached, the legs have the normal grey colour and the nails are darker. The mask has the normal colour.

Interesting fact: the eumelanin reduction on the body of the females is greater than the reduction on the body of the males. The sexual dimorphism in this mutation is an interesting fact and has never been seen before in lovebirds (Sexual dimorphism is the condition where the two sexes of the same species / mutation exhibit different characteristics).

Genetic background.
According to Miriam this mutation inherits autosomal recessive. She was also able to show that

It is striking that the legs have a nearly normal grey colour. This would lead us to suspect that this mutation maybe has something to do with dilute. That is, due to a shortage of dilute birds, the only trial pairing Miriam was not able to set up. But since these birds are born with red eyes we could actually exclude the connection with dilute for 99% already, but genetics would not be genetics if there were no exceptions. It would not be the first time that a few genes were linked and that these lead to exceptions. Therefore, it would be interesting to set up this pairing to be on the safe side, because exceptions do make the rule. Hopefully our project, Agapornis Genome Study [1], can provide more clarity about this in the future.

*Pastel* Agapornis roseicollis?
A lot of people ask the question whether this mutation might be the lost *pastel* Agapornis roseicollis which were bred in the 70s and which were described by Harrie van der Linden? I personally do not think so. A number of points such as the colour of the inner vane of the flight feathers, the colour of the legs and the colour of the body differ. Also, the description of the wings and the rump does not match. The striking difference in colour between the wings and the body is also not mentioned [2, p. 178], [3, p. 364]. For clarity sake, there is yet no certainty about the inheritance and correctness of the name *pastel* for this mutation. I have reached out to Harrie who confirmed 100% that these mutants are NOT born with red eyes and that the eumelanin reduction on the body is evenly spread. Therefore, we can rule out this mutation.

*Faded* Agapornis roseicollis?
For a long time, people thought it might be a faded mutation, a theoretical approach I could follow, but once it saw the birds for the first time in the flesh, I immediately know that this could not be correct. The differences are just too big.

Then what is it?
That is a valid question, it appears that this type was not (yet?) been described. Therefore, it was not easy to name it, let alone to determine the ideal name. For starters we looked for similar mutations within ornithology and aviculture. But we did not find any, so we had to look in other animal species for similar types of eumelanin formation. But even this gave no results. So, we had to determine a name ourselves and of course Miriam also have a say in this. And she named it: Jade.

– Update 2018 – But there appeared a few problems around that name: A (small) number of breeders use the term jade for D green and for them it could create confusion. Another problem, mentioned by Miriam Bisiacchi, the breeder who introduced and named this mutation in aviculture, was that not all judges realised that jade is a dimorphic mutation.

Mr. Jameson Yerevan suggested to use DM (Dimorphemic) in combination with the name jade. It was clear that the use of DM could solve both problems.

Scientifically there were no objections to use DM and since this mutation is (for now) only in Agapornis roseicollis I spook to Agapornis breeders / judges and of course Miriam who introduced and named this mutation. That made it much easier then when this mutation also exists in other parrot species. None of them had objections, so within the BVA international nomenclature we decided to refer to jade as DM jade.

Dirk Van den Abeele

[1]          “Agapornis Genome Study – Information for breeders on the Agapornis genome PhD study”. .
[2]          D. Van den Abeele, Agaporniden, handboek en naslaggids – deel 2, 2013de dr., vol. 2, 2 vols. Over dieren, 2013.
[3]          D. Van den Abeele, Lovebirds Compendium, 1ste dr. Warffum- The Netherlands: About Pets, 2016.

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