Let’s take a look at cockatiel genetics, as it is amazing that so many cockatiel color mutations have arisen in so short a time span in the cockatiel, all of which affect only the production of melanin.
Mutations likely to convert the yellow background color into a deep orange-marigold, now only found on the cheeks, are unlikely and yet far from improbable.
There are several cockatiels around that have some orange-red feathers scattered over the head and body, indicating that such a change can take place, but it would most likely take further mutations rather than skillful pairing to get such a desirable mutation.
The one mutation that is guaranteed to turn up at some time is one that will completely eradicate the yellow and orange pigments.
Such a mutation is as common in parrots as is that for producing lutinos.
The cockatiel will not, because of its feather structure ever be blue like a budgie, but could be black.
If this gene for eliminating yellow is introduced into the lutino, then it will give a bird devoid of all color and produce a true albino of virgin whiteness.
Several people have, supposedly, produced green or blue cockatiels. In the course of their evolutionary history, the cockatoos have lost the ability to incorporate within their feather structure the refractive layer possessed by most other parrots.
Unless this layer can be restored, blues and greens cannot be made.
Not that reverse evolution cannot take place of course. Two other features once selectively lost by cockatiels have made an exceptional reappearance.
One adult hen has been noticed to have regained the ability to beg the male to feed her during courtship. Another cockatiel has been seen using its foot for grasping and holding, which is something that has been impossible for the vast majority of cockatiels for a long period, even though it is common among other parrot species.
The return of the refractive layer to the feathers, to give them a blue or green appearance, may require a far more sophisticated association or mutation of genes to get this reversal of evolution than does the re-acquisition of courtship feeding or been able to use the foot as a hand.
It seems that a lot of bird breeders have very little knowledge of simple cockatiel genetics.
Some of the questions asked are: “What colored youngsters will result if cockatiels of different colors are paired together?” Or “Can a cockatiel be split for two or more colors?” Or “Can a cockatiel be both pied and lutino and, if so, what color will it appear?
Let’s look at a straight forward list of various matings and cockatiel genetics.
This list is not complete owing to the enormous numbers of possible matings. After the list, an elementary account of the principle of inheritance and a broad definition of the words used will follow.
By making the explanations as simple as possible it ought to enable anyone to work outbreeding charts for any crosses they may wish to try.
Here is what cockatiel breeders can expect their offspring to look like with these mating pairs.
- Lutino Male or Female X Lutino Female or Male = 100% Lutino Offspring
- Lutino Male X Normal Female = All female chicks are Lutino and all male chicks are normal in appearance but are actually Split Lutino.
- Normal Male X Lutino Female = Normal female and split Lutino males.
- Lutino Male X Pied Female = Male chicks normal in appearance but split for both Lutino and Pied. Female chicks are Lutino but are also split for Pied.
- Lutino Male X Silver Female = Males normal in appearance but split for both Lutino and Silver. Female chicks are Lutino but are also split silver.
- Lutino Male X Opaline Female = Male chicks normal in appearance but split for both Lutino and Opaline. Female chicks are 100 % Lutino.
- Lutino Male X Cinnamon Female = Male chicks normal in appearance but split for both Lutino and Cinnamon. Female chicks are 100% Lutino.
- Split Lutino/Split Pied Male X Lutino Female = 50% males will be Lutino and half of these will also be split for Pied. The other 50% of the males will seem normal but will be split for Lutino and approximately half of these will also be split for Pied. About 25% of the hens will be perfectly normal and the remaining 25% look normal but are split for Pied.
- Pied Male or Female X Normal Female or Male = 100% Split Pied.
- Split Pied Male or Female X Split Pied Female or Male = 25% Pied, 50% Pied, and 25% Normal.
The list could go on and on, but it would be very repetitive. Cinnamon or opaline can be substituted for lutino in the above, or silver for pied.
Rather than look at the figures above, it is perfectly simple to work them out for oneself once a few simple cockatiel genetics are understood.
A mutation is any abnormality, be it for color or anything else, that can be passed on from a parent to some members of succeeding generations.
A gene is the unit of inheritance. A particular gene will be referred to by the name which describes its main effect, for example, ‘Lutino gene’ or ‘Cinnamon gene.’
A cockatiel will be said to be pure-bred for some color mutations if, when mated to a similarly-colored bird, all the offspring they produce are the same color as the parents.
Recessive And Dominant Genes
If a pure-bred color mutation is crossed with a pure-bred cockatiel of a different color, it will be found that their resulting offspring will be the color of one of the parents or the wild-type grey, or the male chicks will be the wild-type grey and the female chicks the color of the father.
The color that has apparently disappeared is said to be recessive and the color taken by the chicks is said to be dominant.
As an example, if a pied cockatiel is mated to a normal cockatiel, then all the offspring will look perfectly normal.
But the recessive color is not lost for each youngster. Even though it is not visually apparent, they still carry the gene. This is proved because when mated back to cockatiels pure-bred for the color or when mated amongst themselves, they will be parents to more of these visual recessives.
For example, if these normal-looking youngsters (from a pied parent mated to a normal cockatiel) are mated back to Pieds, then they will have approximately 50% of their youngsters normal-looking (they are in fact also carriers of the pied gene) and the other 50% will be pied. Such carrier birds are in avicultural language, called splits.
Genes are carried on string-like bodies known as chromosomes. Each cell of the body, except for the reproductive cells – the sperm and the egg cells – always have matching pairs of chromosomes.
These paired chromosomes are the autosomes. Because the autosomes are paired, the genes that they carry are also paired. As well as the autosomes, each cell carries sex-chromosomes which determine the sex of the bird.
The sex-cells, the sperm, and the ova, contain only one chromosome from each pair of sex chromosomes. When these combine to produce the fertilized egg, the number of chromosomes is restored to the double state.
Each parent, therefore, gives the chick one from each pair of chromosomes, or one of the genes for color.
Chromosome explanations can get very complicated and you can do some more reading on the subject of cockatiel genetics and chromosomes here.
What About Combining Cockatiel Mutations?
Crossing any of the various sex-linked mutations is equally pointless, as the females take but one from either a lutino, cinnamon of laced. The male, although split for any two, always looks perfectly normal.
However, it may be worthwhile to cross Pieds with cinnamons, opalines or silvers. Cinnamons to red-eyed silvers would probably produce very attractive youngsters.
What To Do If You Develop A Fresh Mutation
Some time or other fresh color mutations are bound to arise. The person discovering these is then posed with the problem of what is the best breeding policy to take with regard to cockatiel genetics.
First, it has to be established that this is a genetic mutation and not just a curiosity or a freak of nature.
Second, the mutation wants building up into further numbers as rapidly as possible.
Logically it might be better to prove its genetic foundation by mating the youngster back to one of its parents.
If the mutation were an autosomal recessive then father to daughter or mother to son would give50% of the fresh mutation. If it were sex-linked, then father to daughter would give 25% of the fresh mutation males, 25% of females, 25% of split mutation cocks, and 25% of perfectly normal females.
However, if you left the original parents together, they have already proved their fertility and, if it is a mutation, they would produce other examples in time.
Likewise, chicks take time to mature and young birds are often poor breeders until they are at least a year old. If they were mated to a parent this may actually delay the production of further examples.
Hope that this post has helped you gain a better understanding of cockatiel genetics.