[Monica]

Another reply....

Mick, Scott, Monica, Richard and others

They should not be called 'Tangerine'. The Tangerine name was coined by Jim Hayward for colour morphs that are unable to produce red, not those that suddenly can. So the Tangerine mutations I know about include the Orangeface roseicollis, the Yellowface fischeri, the Yellowface Cockatiel and Yellow phase Lorikeets.

These Sun Conures are Red Suffused birds, equivalent to a Redfronted Turq or Scarlet-chested Parrots. There are strains of this mutation in other species as well, such as Princess parrots.

This mutation is not produced by simple genetics, but is the result I believe, of tandem repeats in a gene that allows red pigmentation in the particular species. Tandem repeats are repeated segments within genes that amplify its effects and they are now known to be the basis of most selective breeding to 'improve traits'. Through dedicate work, breeders are able to gradually select for an 'improvement' in a trait, in effect selecting for individuals with more and more tandem repeats in their Red Suffusion gene.

These selective traits will tend to behave dominantly when outcrossed to normal, but the feature of tandem repeats is that their numbers can vary significantly from one generation to the next and they are not always inherited in a standard Mendellian manner.

Terry