Pets!
Articles
Species
Genetics

ALBS Online
ALBS Membership
ALBS Officers
ALBS Picture Library

Show Standards
Show Calendar
Show Classes
Show Results

Links
FAQs

Essential Genetics for the Terrified
by Chris Rutt

Part 10: Sex & Linkage (2)

At the end of the last section, I asked you to work out the result of pairing a Cinnamon Hen to a Homozygous Light Green Cock, and then to a "Cinnamon Carrier". Here is the grid for the first pairing, Cinnamon Hen to a Homozygous Light Green Cock:

You can see that no VISUAL cinnamons occur, but ALL the cock chicks will be carriers. None of the hen chicks can be cinnamon, since in order that they become hens, they MUST receive the "Y" chromosome from their mother. Likewise the cock chicks must all get the cinnamon gene from their mother, since they "need" the "X" which carries it to go with the "X" from their father to make them cocks. Here is the grid for the second pairing, Cinnamon Hen to a Cinnamon carrier Cock:

In this case you can by now work out for yourself that half of the chicks, irrespective of sex, will be visual cinnamons and that all the cocks are visually cinnamon, or can pass cinnamon on to their offspring. Let us also look at one other combination....

This can be a useful combination when you wish to perpetuate a cinnamon line of birds. You can I hope see for yourself that a Visual Cinnamon Cock has been mated to a normal hen. ALL the hens produced are cinnamon, and all the non-cinnamon chicks are cocks which are "Carriers" (or "splits"). Remember that American Cinnamon can be combined with all the other colours.

Two other commonly encountered genes in the Peachfaced Lovebird are also sex-linked. These are the Ino, and the Australian Cinnamon. First let me explain the use of the term "INO". It is often confusing to the beginner in genetics if we introduce them first to the words "Lutino" and "Cremino" and "Ivorino". It will be far simpler for you to understand the breeding of all these colours if you consider the gene which is transmitted as "Ino", which is combined with the three colour series which we have met in earlier sections, namely Green, Marine and Lavender to produce, respectively, "Lutino" and "Cremino" and "Ivorino".

In the event that a true "Blue" is ever produced in the Peachfaced Lovebird, a combination with "Ino" will give us the "Albino" form. It is for this reason that we must never give in to the temptation to describe "Pastel Blue" as "Blue" (as has occurred in "Cage & Aviary Birds"). The use of the term "Marine" reduces the risk of such misunderstandings taking place. For similar reasons I recommend the use of "Lavender" rather than "White faced Blue". Note that this gene inherits in the same way as American Cinnamon, which we have already considered in detail, IN THE PEACHFACED LOVEBIRD.

In the "Eyering Species" the "INO" gene behaves more akin to a simple recessive. It is also similar to the Peachfaced "Lavender" mutation in as much as its presence in a single dose will show in the phenotype when it occurs in combination with the recessive "dilute" gene, producing what are known in the UK as "Visual Splits". JPG pictures of a Dilute Green Masked and a Dilute plus Ino Blue Masked have been loaded to the Bird Graphics library (editors note: A link to this library will be provided in the future. -el).
The Ten Parts of this File on "Basic Genetics" will, I hope, have given you sufficient working information to understand the fundamentals of colour breeding in birds in general and Lovebirds in particular. All you need to know now is which gene is dominant or recessive to which other, which are incomplete dominants and which sex linked. For further information on this, and to take your knowledge a little further if you wish, you could check out "Colour Expectations of the Peachfaced Lovebird made easy" by P.C. Davies & P.J.Davies . It has no ISBN #, and is not dated, but, although old is still obtainable from the UK Parrot Society or the UK Lovebird (1990) Society.

Some mutations which have occurred since its publication include the Orange Faced Peachface (too all intents and purposes a simple recessive, though "splits" can be detected visually by those familiar with the mutation. Technically therefore this should be considered an Incomplete dominant, but where a single "dose" has very little effect on the phenotype. The orangefaced mutation looks very well on green series birds, including Lutinos and Fallows but ill suits other colour series, turning as it does a muddy yellow on Marines.

The Beautiful Violet mutation is an Incomplete dominant. Said to occur in both Danish and Dutch forms, there is much dispute as to whether these are in fact genuinely separate mutations. Particularly attractive phenotypes are produced when combined with Lavender genes.

Two fallow mutations exist, known in Europe as the East German and the West German Fallow; both are sex linked, and definitely different mutations.
Two other even more recent mutations are the Yellow faced (not to be confused with the appearance of the "Orange faced" gene on a Dutch Blue) and Rose faced Peachfaced. These are both reported from Denmark and nothing has yet been divulged as to their mode of inheritance.

May I be permitted to end with a plea. When we begin with Lovebirds there is an understandable urge to play with colours like a child with a paint box, we mix them all up and hope something beautiful will emerge. I would encourage breeders to adopt a more organized approach; decide what colour you wish to produce, use your knowledge of genetics to work out on paper how it may be obtained and do that and please keep records. Finally, never forget, the wild form of the bird is still very beautiful and should if possible be retained in a separate "stud" by at least a significant proportion of breeders. As a caution I will point out that it is now very difficult indeed to obtain quality green Masked Lovebirds in the UK, and almost all are split for blue. A sorry state of affairs.

All rights reserved © 1997-2000 Chris Rutt