personatus fallow

Pour ceux qui maitrisent un peu l'anglais voici un article assez intéressant sur cette mutation :

A very important pure mutation that was produced in mid 1970s is the fallow masked. This bird originated in the collection of Kay Parcell of Southern California, in her outdoor colony of blue maskeds. The fallow masked is described as a light-blue bird, and it appears very similar to the dilute blue masked, but with red eyes. In the green series, it looks much like a dilute green masked with red eyes. Fallow masked are like many other mutations in that not only do they produce the visible Mutation, but they also produce birds that look normal but are split to fallow. This mutation is of extreme importance; because it is one of the few pure lovebird mutations that has been developed here in the U.S.

According to Kay, the visible fallow is somewhat of a delicate mutation that should be aviary-bred as opposed to cage-bred. Visible fallows are flighty, sensitive to sunlight and need places to hide, such as nest boxes, which should be left up year round. Kay believes that this could possibly be because of poor vision. If this is so, then this might account for their flightiness and desire to stay out of the direct sunlight. Kay has had great success by allowing her birds to choose their own mates. This is done by releasing several birds into one flight and, thus, forming a colony. Kay cautions against breeding a visible fallow to a visible fallow. Again, these are delicate birds, and breeding a fallow to a fallow is likely to produce birds with birth defects. the best results come from pairing a visible fallow to a split. The result of this type of pairing is 50 percent fallow, and 50 percent split fallow.

Kay has had a difficult time establishing this bird but not because they are difficult to breed. In fact, she says they breed readily for her and are good parents. The difficulty has been in keeping her breeding stock. Originally, she gave nearly all of her birds to a lovebird breeder who is a genetics expert. The breeder was to establish them but, so far, has not been as successful as was hoped. A few years later, a thief stole nearly all of her fallows and splits; therefore, she had to start all over again. Fortunately Kay is now to the Point in her breeding program where she will probably have a sufficient number of young to sell. This mutation deserves careful attention from the avicultural community, and those of us who enjoy Love Birds appreciate Kay's diligence and commitment to the fallow mask.
Notes of Mark J. Roberts on Eye-Ring lovebird species.

Fallow

Not Ino but still a bird with red eyes—this is the image that most breeders conjure up when they hear the term ‘Fallow’. And this is correct. In all mutations described as Fallow the eumelanin in the eyes has been reduced in one way or another, causing a deviating eye colour. However, because eumelanin is still present in the feathers these birds are definitely not Ino mutations.

In the existing ornithological literature Fallow mutations are described in different bird species. Because multiple Fallow mutations have appeared within certain species it has become necessary to categorise these Fallow mutations. What is important, of course, is the genetic make-up of the mutation and the pigmentation changes in the feathers.
In earlier times there was little exchange of information between mutation breeders. For this reason, we now note that within different species there are at least the same number of different names for these Fallow mutations and consequently different names created for the same Fallow type. However, if we look at the list of existing mutation names we see that various colour strains were also labelled Fallow, while other breeders called existing Fallow types names like ‘Recessive Cinnamon’, ‘Buttercup’, ‘Yellowhead’ and ‘Yellowtail’. These names usually sounded fine but did not mean much with respect to the pigmentation and the genetic make-up of the bird.

As is typical for these different Fallow types, all of these birds have a certain reduction of eumelanin in the feathers and the eye colour varies from bright red to burgundy—two criteria which must be met for Fallow. However, there is a third criterion—this Fallow type must also have an autosomal recessive mode of inheritance.

In an attempt to subdivide the various Fallow types into groups a number of international talks were organised. Granted, Fallow is definitely not an easy matter to come to grips with, but many have tried to find their way through the maze of the existing Fallow mutations. I will also try to do so, based on the information available and the current research results.

According to the international agreements through Dr Terry Martin’s Genetics–Psittacine Group the existing Fallow types are subdivided into a preliminary list of ‘Bronze Fallow’, ‘Pale Fallow’, ‘Dun Fallow’ and ‘Ashen or Smokey Fallow’. These divisions are based on the reduction of melanin in the feathers.

* In Bronze Fallow the black eumelanin is reduced to brown.
* In Pale Fallow the black eumelanin is reduced to light brown.
* In Dun Fallow the black eumelanin is reduced to grey-brown.
* In Ashen Fallow the black eumelanin is reduced to light grey.

Let me add at once that I have my doubts as to the existence of the Ashen Fallow as a separate mutation. However, to be 100% certain, much research still needs to be done. Dr Martin makes the distinction for Ashen Fallow based on the eumelanin colour change in the feathers.
Although these subdivisions are definitely a good start, I personally find that this level of distinction is insufficient. Determining a mutation by sight alone is very dangerous, especially if it is based on the difference between the colours brown, grey-brown, etc. Personal interpretation and the ability to clearly distinguish certain colours will undoubtedly play a crucial role here.

To date, the Budgerigar is the only bird species for which three different Fallow types have been documented In this species these are defined as ‘German Fallow’, ‘English Fallow’ and ‘Scottish Fallow’. For the record we need to mention that the ‘Scottish Fallow’ is thought to be extinct or at least that there is no evidence of any ‘Scottish Fallows’ existing in aviculture at the present time. (As was often the case in earlier days, the country of origin of the first mutation was often incorporated into the name and could thus differ from one species to the next. For example, what was called ‘English Fallow’ in Budgerigars was called ‘East-German Fallow’ in lovebirds.) Strangely, in Budgerigars these three Fallow mutations exhibited little difference in their feathers. It was the eye colour which was the qualifying factor.

* ‘German Fallow’ has dark red eyes and a white iris band.
* ‘English Fallow’ has ruby-red eyes but without the white iris band.
* ‘Scottish Fallow’ has plum-red eyes but without the white iris band.

Despite the various attempts to get clear descriptions of these three different Fallow types in the Budgerigar no-one could supply me with sufficient information about the precise colour of the quills in these mutations. However, various breeding reports proved that in Budgerigars we were definitely dealing with three different, non-related mutations. Harry van der Linden, a leading specialist in the field of Budgerigars, is very certain about this. At one point in time he owned the three different Fallow types and as a result he had the opportunity to pair them together. The resulting offspring were always wildtype Green split birds, an undisputable piece of evidence confirming that these were, indeed, three separate mutations.

In lovebirds there are two, perhaps three types. What is striking here is that there is a distinctive colour difference between the various Fallow types. In Indian Ringnecked Parrots there is mention of two Fallow types, and as in lovebirds a distinctive colour difference is noticeable in the feathers.

How is it possible that the various Fallow Budgerigar types only differ in eye colour with no clear difference in the feathers, while in lovebirds there is a difference in eye colour and feather colour? I personally attribute this difference to the fact that in Budgerigars eumelanin is also present in the cortex of the feathers. This eumelanin is responsible for the dark wing pattern, a pattern which is not present, for instance, in lovebirds and Indian Ringnecked Parrots and consequently no eumelanin can be found in the cortex. It is not inconceivable that the eumelanin in the cortex is scarcely or not at all affected by the Fallow mutations. But again, this is my personal approach and to date I have not found any scientific evidence for this. Considering that in one species there is a notable colour difference in the feathers while there is scarcely any in another species is, in my opinion, a more important guideline for determining the Fallow type is the eye colour and the genotype of the bird.

Bronze Fallow
Bronze Fallow is an autosomal recessive mutation found amongst different parakeet species. In lovebirds this mutation has occurred in the Peach-face Lovebird Agapornis roseicollis, the Abyssinian Lovebird A. taranta, the Fischer’s Lovebird A. fischeri and perhaps the Masked Lovebird A. personatus.
In lovebirds the general body colour of the Bronze Fallow is laurel-green (green with a brownish haze) and the quills are grey-brown. The feet are flesh-coloured and the toenails horn-coloured. Of course, the psittacin is not affected.

A study of feathers revealed that this mutation, just like NSL Ino, is a type of tyrosinase negative (Ty-neg) albinism. Whereas in NSL Ino the tyrosinase activity is completely lacking, in Bronze Fallow it is reduced. The MUTAVI Research and Advice Group examined the eyes of the Bronze Fallow and the corresponding mutation in the canary—the Topaz. In both cases visible eumelanin of a poor quality is present in the choroid (a dark pigmented layer found at the rear of the eye beyond the retina) and also at the rear of the iris. This is why the Bronze

Fallow has burgundy-coloured eyes. Keep in mind that the tissue at the front of the iris is not the same in all bird species. The a-locus affects the tyrosinase activity. This is caused by a point mutation, which can result in a different gene fault for each bird species. A mutation altering only one base pair in the DNA sequence. This results in a single amino acid being substituted in the makeup of the protein (tyrosinase). Changes in amino acid sequence cause changes in the folding of the protein, altering its activity, function and sometimes its production. This could mean that Bronze Fallow is an allele of the a-locus.

Recent studies within the MUTAVI Group have amplified this suspicion. In the Elegant Parrot Neophema elegans presumed Bronze Fallows were regularly crossbred with NSL Ino, resulting only in intermediary-coloured Fallows with red eyes. These birds were incorrectly called ‘Lacewing’ in The Netherlands. In my opinion, the ultimate test to determine whether this mutation is a Bronze Fallow or not is to combine it with NSL Ino. As soon as a wildtype young appears we will know enough to rule out Bronze Fallow. It goes without saying that, except for trial pairings, in Bronze Fallow all combinations with known alleles of the a-locus (eg NSL Ino, Pastel and Dark-eyed Clear) must be avoided. These combinations always result in intermediary types—and more confusion. To avoid confusion about their identity, these phenotypes should not be given a separate name. According to the international conventions these types are named by linking both allele names together, each one starting with a capital letter, eg Bronze FallowIno, Bronze FallowPastel, Bronze FallowDark-eyed Clear, etc.

Pale Fallow
Although we can fall back on the genetic make-up of Bronze Fallow, Pale Fallow is slightly more difficult to distinguish. In lovebirds, for instance, Pale Fallow has almost completely yellow eyes, while in other species this is less clear. The question then is how to distinguish between Pale Fallow and the other Fallow types in other species of parrots.
During our research we discovered that the Pale Fallow locus (pf-locus) affects the matrix of the melanosomes (pigment grains) which has a strong effect on eye pigmentation. In contrast to the Bronze Fallow which has burgundy-coloured eyes, this mutation has bright red eyes which give the impression that you can see right through them. That occurs because in the eyes of the Pale Fallow no visible eumelanin can be found in the choroids and the rear of the iris. Nevertheless, the birds do not appear to be bothered by the light.
In lovebirds Pale Fallows are heavily bleached. However, is this the case for all species? It is a fact that the Pale Fallow is autosomal recessive in inheritance and that this mutation is not an allele of any other known locus.

I am starting to suspect that the ‘English Fallow’ Budgerigar is the equivalent of the Pale Fallow. The eyes of these birds are described as bright but without a white iris band. The body does not show much eumelanin reduction.

Dun Fallow
This Fallow type reduces the black eumelanin to grey-brown. The eye colour is not mentioned. Thus the definition of Dun Fallow is very minimal scant. If I project this information onto certain parrot species, the Pacific Parrotlet Forpus coelestis is a possible candidate for Dun Fallow. In this species certain Fallows have a bright red eye and a limited reduction of eumelanin in the feathers. We suspected that this type might be Bronze Fallow but, according to most breeders, test pairings with NSL Ino have produced only wildtype Green birds. This would indicate that these birds are not Bronze Fallow. If we compare the eye colour of a proven Bronze Fallow with a Fallow Pacific Parrotlet we indeed see a big difference in colour. In the Fallow Pacific Parrotlet the eye colour is a very bright red, whereas in Bronze Fallow it is burgundy.

Other breeders confirmed that certain Fallows in the Pacific Parrotlet do have dark red eyes and a slightly less reduction of eumelanin in the feathers than the Fallow specimens with bright red eyes. Could there be two types and is the one with the darker eyes a Bronze Fallow? It would definitely explain why certain breeders most emphatically assure us that the bright eye within the clear iris is a characteristic of Dun Fallow. Perhaps it is the equivalent of the ‘Scottish Fallow’? An ultimate test would be to pair both types and if the resulting offspring are wildtype Green, then we can be certain that there are at least two types.

Smokey or Ashen Fallow
This mutation has only been named in Cockatiels and Scarlet-chested Parrots. However, considering that the feathers of these birds are not of the structural type, it is very dangerous, in my opinion, to compare this type to birds with a different type of feather. Personally I suspect that this mutation might, in fact, be one of the other three Fallows.

Faded
Although this mutation, which appears quite regularly, also has a deviating eye colour, surprisingly it is not linked to the Fallow types. In this autosomal recessive mutation the young hatch with red eyes which darken over the first few days.
Nevertheless, these birds will never have the normal eye colour of a wildtype bird. For example, in the Faded Budgerigar and the Faded Swift Parrot the normal white iris is lacking. In both species the eumelanin reduction is most noticeable on the body. Personally, I suspect that this Faded mutation could be a ‘slight’ form of Fallow.

Conclusions
We have not heard the last about this division of the Fallow mutations. Personally, I feel that the distinction will have to be made based on eye colour and genetic make-up. Dividing Fallows merely according to a reduction of eumelanin in the feathers seems unreliable. The various Fallow mutations among Budgerigars have proven this. In this species it was only possible to distinguish between them based on eye colour.
Dirk Van den Abeele
MUTAVI, Research and Advice Group

On verra plus tard pour lire ce texte

AÏE !!! J'y comprend rien

on va s'occuper de faire un résumé en français Corinne

Merci bien , désolé mais l'anglais et moi on est faché

Coco a écrit:

Merci bien , désolé mais l'anglais et moi on est faché

pas de soucis Corinne

en attendant voilà à quoi ca ressemble en série verte.
Il s'agit d'un double facteur foncé (appelé aussi olive).

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donc l'image est plus parlante moi je dis !
il a des yeux rouges comme tout les fallows et cette teine olive est très sympa je trouve ,double facteur pour la teinte donc deux facteurs foncés ?

Exact Laurence c'est un oiseau de série verte qui a deux facteurs foncé de plus qu'un type sauvage ce qui lui donne cet aspect olive.

C'est très joli je trouve et rien ne vaut une image , ça parle mieux .

Une mutation que je serais curieux de voir en vrai.

Un autre sujet en série bleue cette fois

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Toujours des difficultés à obtenir des informations,au même titre que d'autre Fallow tout aussi rare.

oui moi aussi christophe, pourtant je cherche, j'en suis même rendu sur des sites indonésiens

Les premiers sujet viennent des USA alors je suis pas partis voir par chez eux ,mais ils sont tous passés sur du Personata Yellow Face

vraiment dommage car c'est une mutation trés intéressante....

On commence à voir quelque nouveauté intéressante à suivre,voilà un qui me déplait pas issue de croisement de mutation et j'ai pas encore tout compris pour l'heure j'en suis au faded sable.

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il est à tomber tu veux dire!!!!!! merci du partage, le rendu du gris est magnifique, surtout avec le contraste du masque balnc.

On a les même goût alors pour ceux et celles qui seront au BVA de septembre le Faded sera en présentation normalement.

j'espère vraiment qu'ils vont la développer cette mutation, l'histoire qu'on puisse en avoir....d'ici 20 ans!

Tout dépends des éleveurs et le blocage fait.

M.A.G.N.I.F.I.Q.U.E.S

y'a vraiment de belles choses qui arrivent chez le fischeri
entre sa et l'opaline, il va y avoir des combinaisons intéressantes d'ici quelques années!

faut juste qu'on oublie pas de continuer à travailler les autres mutations et surtout les types sauvages

tout à fait d'accord!!

le type sauvage devrait être dans tous les élevages, il est tellement beau.
Je me fais pas trop de soucis pour sa, y'aura toujours des puristes pour y veiller.

abys a écrit:

tout à fait d'accord!!

le type sauvage devrait être dans tous les élevages, il est tellement beau.
Je me fais pas trop de soucis pour sa, y'aura toujours des puristes pour y veiller.

je suis moins optimiste que toi sur ce coup là, il suffit de voir à quel point il devient de plus en plus difficile de trouver du beau TS.

à nous d'y remédier alors,
je ne suis pas le mieux placer car je n'en ai pas pour le môment (sauf mon ts personatus)

mais lorsque l'occasion se présentera je compte bien avoir quelques couples ts
le ts est indispensable aussi bien pour sauvegarder la pureté de l'espèce que pour travailler nos mutations.

prenons en soins

Sa existe du vert pure

Christophe a écrit:

Sa existe du vert pure

j'aspire aussi à y croire....