The ever lasting discussion about the question whether the "Australian cinnamon" peach
faced lovebird is a true cinnamon or not can be answered if we take some facts in
The first specimen ever bred, hatched in the early seventies in a colony of normal wild-type peach faced lovebirds, thus no other mutations were involved according to this information. So the first mutant must have been a hen because the mutation soon proved to be sex-linked.
The mutation was established, released in the mid seventies and later on compared to the "American cinnamon" which is also sex-linked.
Originally the "Australian cinnamon" was described as having grey flights and the "American cinnamon" as having brown flights. However,exporting and introducing the "Australian cinnamon" into the breeding programs of the "American cinnamon", which was established in the USA in 1971 or 1972 , is probably where the confusion came in. Both mutations hatch with red eyes which darken after about a week.
The Australian fanciers probably used the Budgerigar definition for sex-linked cinnamon to name this mutation after its first appearance. They obviously ignored the fact that the flights were grey instead of brown although they did mention it in their first descriptions.
Nowadays we know, thanks to testmatings and feather investigations, that the "Australian cinnamon" is in fact a sex-linked par-ino mutation [1,14]. In other words, the "Australian cinnamon" is an allele of the sex-linked ino-locus and is called "pallid" nowadays. The "American cinnamon" is the only true cinnamon, also sex-linked but resides at another locus.
The distance between these two loci is known for years, about 3 cMorgan which stands for a crossing-over value (C.O.V.) of 3% .
One should refer to these mutations as cinnamon for the "American cinnamon" and pallid for the "Australian cinnamon". The reason for that in the first place is that we must abandon country names in naming mutations because it is unnecessary, only serves commercial purposes and, in the second place the "Australian cinnamon" is not a true cinnamon. There is only one true cinnamon and one true pallid, period.
A cinnamon has cinnamon brown flights and a pallid has grey or light grey flights. The colour of the cinnamon flights is normally stable except in direct sunlight which bleaches the primaries dramatically in some cases. Direct sunlight has no effect on the colour of the flight feathers of the pallids because black eumelanin incorporated in feathers is insensitive to sunlight.
I have done microscopical investigations on sex-linked pallids in several different psittacine species and even in finch-like species (where it is called agate) and my conclusion is that the grey flights contain deformed black eumelanin granules showing a lesser density and a smaller amount compared to the wild-type. Again, in all cases these granules were definitely black and not brown. These results fit in the description of the pallid as it was presented by Australian fanciers in the early seventies.
Nowadays there is a tendency to believe that the current pallid differs from the original pallid developed in Australia and, unfortunately, I think there might be something else at play.
Flight feathers of the contemporary pallids are described as exhibiting a cinnamon tinge, beige has been mentioned and sometimes even sand coloured. The question is are these birds the result of crossing-over between the true cinnamon and the pallid or not.
Since we know the distance of these two loci (3%), the chance would be very small (3 out of 100 offspring) but not impossible, however, once established, both genes lie very close together and are less likely to be separated by a break and crossing-over. This could have left us behind with several different situations.
The formula of a normal pallid is Z ino pd/Z ino pdfor a cock and Z ino pd/ W for a hen. They should display the original grey flights as described by the Australian fanciers.
The formula for a PallidIno cock, which is derived from an ino cock x pallid hen or vise versa, is Z ino pd/Z ino. Such cock should display light grey flights.
Than there is the possibillity of crossing-over between cinnamon and pallid resulting in cinnamon-pallid hens in the first place and in a later generation also cinnamon-pallid cocks. The formula is Z cin_ ino pd/Z cin_ino pdfor such cock and Z cin_ ino pd/ W for a hen. I can imagine that this combination displays beige flights. And one could even have created a more rare combination; the cinnamon_pallidIno cock. As a formula: Z cin_ ino pd/ Z cin_ ino. Such cock displays possibly flights with a cinnamon tinge or a sandy colour. That would make sense to me.
However, there are a few other questions that came to mind following the discussion on the internet.
1. Under what circumstances were the discussed birds judged. Were they judged in broad daylight or in artificial light.
2. What was the skin colour at hatching. A true cinnamon has a pure albinotic skin at hatching, was this ever compared to pallid hatchlings?
3. Are their flights bleached in direct sunlight or not.
Using Google I found more than 600 hits for "Australian cinnamon". According to one site "Australian cinnamon" is also known as "Australian ino" (to increase the confusion....).
It was obvious to me where that came from; D'angieri introduced this in his "Colored Atlas of Lovebirds" .
Although I find this book very debatable at many points, D'angieri is specificly right about this mutation. He states:- This sex-linked factor was at first taken to be a cinnamon series mutation.Certainly it is not a cinnamon bird, but today it is still known as Australian Cinnamon.-
-When the American ino factor was added, the results were surprising: the Australian showed itself dominant to American Ino.-
And further on he states: -The correct appelation should be Australian lutino, not quite perfect but, without doubt, more correct than the cinnamon that is still very widely used.-
However, he is wrong about his description of the (American) cinnamon, the only true sex-linked cinnamon in love birds.
He states: - The appearance results from a dilution in melanin concentration, in which case the phaeomelanin predominates, which itself is nothing but a smaller concentration of melanin pigment, in smaller granules.-
D'angieri's assumption that cinnamons show phaeomelanin is false. In the first place psittacine species do not posses any phaeomelanin whatsoever because they lack the genetic makeup for producing any, and in the second place; cinnamon eumelanin granules have almost the same size and shape as black eumelanin granules. Electron microscopical examinations provided us with evidence for that already several years ago .
The SL cinnamon locus normally converts brown eumelanin into black during the final step in eumelanogenesis, if it fails to do so by mutation, the eumelanin stays brown. It is as simple as that.
The SL ino locus does not affect the colour of the eumelanin but obviously controls the production of the matrixes of the eumelanin granules. In SL inos severely underdeveloped and deformed granules have been found in flight feathers through electron microscopical examination . Their amount is approximately 5% compared to the wild type and causes ghost barring in wingcoverts of SL ino budgerigars, SL ino fowls, turkeys and quails for instance [4,6,7,11,12,14].
Ghost barring is the faint nearly invisible sex-linked barring pattern that you sometimes see in the species mentioned. Often you have to look at a bird in certain lighting or at some angle to see it clearly. These birds are definitely barred, but you have trouble seeing it.
In SL pallids, solid black considerably less deformed eumelanin granules have been found through light microscopical examination of flight feathers. Their amount is often less than 40% in most species investigated.
The difference between black and grey flight feathers is not the colour of the eumelanin granules but rather their density and their amount. A lower density going together with a lower amount displays a greyer appearance.
In spite all of this, supporters of the brown, beige or sand coloured flights are very stubbern about their observations and, having seen several pictures of the so called "Australian cinnamons" on the Internet, I am inclined to see their point. My earlier suggestion that crossing-over could have occurred in the early days when the "Australian-" was mixed up with the "American" cinnamon, (maybe to try to "improve" the colour of the flights because they were grey instead of brown), urges itself.
After crossing-over has occurred, the cinnamon- and the ino-locus are very closely linked (3 cMorgan) and the new combination (almost) breeds true (97 out of 100 offspring).
Since the pallid is an allele of the ino-locus, the same goes for this combination.
In this article I want to put forward the proposition that most of the pallid peach faced lovebirds seen in the USA are in fact cinnamon-pallids and cinnamon-pallidIno descendants as a result of an "unrecognized" crossing-over between the cinnamon and pallid alleles which probably already took place many years ago.
In Europe it is a well known fact that 80% of the pallid peach faced lovebirds seen at the BVA shows in Belgium, which is considered the most important and greatest lovebird show today, have grey flights.
To unravel this and avoid endless discussions, one shall have to put it to the test and mate the (American) beige flighted pallid to the (European) grey flighted pallid to see what happens. The question remains whether one is willing to do so.
However, maybe this all will not be necessary because of the following.
If two proven sex-linked mutants mated together produce no wild type offspring than they are alleles of the same locus. This goes also for autosomal mutants, every geneticist will agree to that.
After studying all information provided by American sources claiming that the "Australian cinnamon" is not the same as the "European pallid", there is still one thing that is bothering me. Matings between "Australian cinnamon" and inos never produced any wild type offspring. Matings between "European pallids" and inos either. This can only lead us to one conclusion and that is that the "Australian cinnamon" and the "European pallid" represent one and the same allele of the sex-linked ino locus in Agapornis roseicollis just as in several other psittaciformes.
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