The cockatiel, Nymphicus hollandicus, or Quarrion, is a perfect avicultural subject. Originally from Australia, many thousands are reared commercially worldwide for the pet industry. The American Cockatiel Society has established a standard of excellence for the exhibition minded fancier.
The cockatiel now occurs in six well-established mutations. These factors, three sex-linked recessive and three autosomal recessive, all affect the coloration of the plumage. Some traits also change the eye color from black to red. Many other color variants are reported. Some of these new colors are definite mutations in the process of becoming established. Others are simply combinations of pre-existing varieties or are imaginitive names used in sales pitches.
The normal cockatiel is slate grey, reminiscent of a blue domestic pigeon. Some white extends from the wing butt down the outer edge of the wing. The cheeks have orange patches. A yellow suffusion covers the entire bird, more so in the males. The yellow suffusion is especially prominent in the head and crest of the cock. Adult hens have horizontal bars going down the tail.
The Lutino is the most widespread cockatiel mutation. In the United States Lutino cockatiels are right behind the Budgerigar as far as popularity is concerned. The Lutino is a white bird with variable yellow coloring. The yellow is the same suffusion of the normal, but in the normal bird much is hidden by the grey coloration. The eyes are red and the orange cheek patches are retained. Though not as obvious as with the normals, Lutinos may still be sexed by means of color. Though no melanin is present, the yellow in the tail of the hen still retains a barred pattern.
This abnormal coloring is caused by a total lack of melanin due to an inability to synthesize the enzyme tyrosinase. This factor is sex-linked recessive.
Particularly in Great Britain, heavily suffused Lutinos are sold, at a premium, as Primroses or Buttercups. An extreme few fanciers, through selective breeding, do possess strains that are consistently more brightly colored. This attractive appearance is derived from a slow accumulation of desirable modifiers. Genetically, these Primroses and Buttercups are, albeit superior, Lutinos. Unfortunately, the great majority of advertised Primroses and Buttercups are only fractionally more colorful. This small improvement might even be from ingenious lighting!
Lutinos were originally described in the United States as Albinos. This is no longer a good practice, for true Albinos are now being produced through multiple mutations.
The Cinnamon was the second sex-linked recessive mutation. Here the grey of the normal is turned to a deep brown. This melanin color is extremely variable. Cinnamon cockatiels have various shades of brown. Cocks are most often darker than the hens.
The term Isabelle is sometimes used in connection with this color. The cockatiel color is not similar to the Isabelle found in either the canary or the domestic pigeon. It is almost always preferable to use the same name if an analogous color occurs in the budgerigar. With this in mind, it is better to use Cinnamon.
The Pearl, sometimes called Lacewing, is the final well- established sex-linked color. The color of this variety is very similar to the lacing seen in the Oriental Frill breed of domestic pigeon. In the cockatiel the outer edges of the feathers of the head, back, mantle and sometimes chest are colored. This produces a scalloped effect. This scalloping is variable. A poorly colored specimen might seem to be a normal grey with a few pale feathers. The better birds show only a fine pencilling on the edge of every feather.
The Pearl is regularly only seen in hens. Cock Pearls molt out to the normal color with, rarely, a few white flecked or laced feathers. These adult males masking Pearl may sometimes be discerned by examining the tail feather at the quill. A small amount of yellow will be noted in this area.
We may speculate upon the change of color of the adult Pearl males. This plumage may be under hormonal control. An alternate explanation is that homozygous pearls appear normal. Certain autosomal factors drop out in this manner in the budgerigar. It is impossible to obtain a two factor hen Pearl. Being a sex linked trait the hens are necessarily homozygous.
Young hens could be treated with male hormones to experimentally determine if this is the cause of the transformation. If hormones produce no change in the lacing, then genetic control may be inferred.
The Pied is th ony popular autosomal recessive trait. The melanin is deleted in random patches. Pieds cannot be sexed according to the barring in the tail. Carriers of Pied sometimes show white or yellow flecking on the back of the neck.
Most people consider the lighter Pieds to be more attractive. These heavy Pieds sell at higher prices. A few strains of heavy Pieds exist. Most often this trait is of variable penetrance. A pair of heavy Pieds may fail to produce any heavy Pieds. The reverse is also true.
The Fallow is a red eyed brown cockatiel. This trait is also an autosomal recessive. As in the Cinnamon, the shade of brown is variable. Fallows are most often lighter than Cinnamons. Again as in the Cinnamon, cocks are on the average darker than hens. Some Fallows are two toned. Thomson (82) reports that the head and body are golden yellow and the wings are tan.
The White Faced mutation is the most recent autosomal recessive mutation to become well-established. This factor deletes the yellow suffusion and orange cheek patches. This yields a charcoal colored white faced cockatiel. Some writers have indeed given the name of Charcoal to this variety. Cooper (81) states that some call them Blues. Even though this follows the rule of using budgerigar terminology, this name is best avoided. The feathers of the cockatiel possess no refractive layer so no sky blue, as in the budgerigar or blue jay, is ever displayed.
The White Faced is most interesting in combination with the Lutino. A White Faced Lutino is a true albino. Here we get a pure white red eyed bird. True albinos are in very short supply.
Through combinations and crossing over many blends of colors may be achieved. Some of these combinations, i.e. Pied- Cinnamons, Pied-Pearls, Lutino-White face, Cinnamon-Pearl look exactly as would be expected. Others are not so elementary. In genetics the whole does not always equal the sum of the parts!
Smith (82) reports a Marbled cockatiel. Here we observe a silver grey bird with the mantle feathers scalloped by lighter grey. This bird is almost certainly a Cinnamon-Ino, a combination of the Cinnamon and Lutino derived from crossing over. This combination is called a Red Eyed Lacewing in the budgerigar. Roper(82) notes that Lutino-Pearls are being sold as Golden Laced. This last combination is particularly interesting for Thomson (82) notes that some Marbled cockatiels molt out normal. This would be as expected for any males that were heterozygous for Pearl.
Three different Silver or dilute mutations have been reported. All are very poorly understood. Smith (82) describes a very pale sex linked recessive Silver. Eye color is not given. Thomson (82) reports on a variable shaded Silver with red eyes. This variety is noted for poor eyesight and are autosomal recessives. Birds manifesting this trait may be either Silver or Brown. Cole (81) notes that a Black Eyed Silver mutation exists. This mutation is of extremely variable penetrance. Some of these Black Eyed Silvers cannot be distinguished from normal greys. Others could be taken for black eyed clears. All intermediate shades also occur. This factor is presumed dominant.
Smith (82) states that he has received rumours of Green cockatiels but had not seen any evidence.
Cole, T.G., 1981, “Dilute or Blackeyed Silver Cockatiel”, The Magazine of the Parrot Society, vol. XV, no. 10, p. 272
Cooper, N.D., 1981, “The Whitefaced Cockatiel”, The Magazine of the Parrot Society, vol. XV, no. 10, Oct., pp. 252-253
Roper, M.D., 1982, “Fanciful Names of Cockatiel Mutations”, The Magazine of the Parrot Society, vol. XVI, no. 11, Nov., p.346
Smith, G.A., “Some Ringneck (Psistaculla frameri) and Cockatiel (Nymphicus hollandicus) Mutations”, The Magazine of the Parrot Society, vol. XVI, no. 7, July, pp. 214-217
Thomson, 1982, “Cockatiel Mutations”, The Watchbird, vol. IX, no.