In 1996 I had the opportunity to exhibit at the Texas Bird Breeders and Fanciers Show. There, I met Margie Mason, the originator of the mutation and got to see her Emeralds for the first time. They are truly unusual, looking as if coarse yellow and grey sand had been mixed and then poured on the birds. The lighter ones really did look emerald and the darker ones more of an olive color. The main effect of the mutation is to render the center of each feather clear of melanin pigment, yet leave a dark edge. In non-technical terms, it looks like the reverse of Pearl (Opaline). The difference in them may not be one of melanin reduction, rather melanin redistribution. There are variations in beak and leg color in different specimens. There has been much speculation and not much written on the subject of the mutation, some of it is contradictory. In recent times my esteemed counterpart in the National Cockatiel Society has suggested calling the mutation 'Suffused Yellow' instead of Emerald. In aviculture the term Suffused is used to describe any parrot species with approximately 80% dilution in melanin pigment. Suffused is just one of a number of Dilute mutations, Budgerigars have three – Greywing, Clearwing and Dilute (or Suffused). Suffused Yellow is a confusing name in that it implies a suffusion of yellow. In fact the yellow/orange psittacin pigments are not at all affected, only the melanin. In terms of international agreement on psittacine mutations this morph might be better named Suffused Grey or Greygreen.
Dr. Terry Martin of Brisbane Australia, who can be considered an authority on psittacine color mutations, wrote the following on this subject: "There is a form of dilute mutation which internationally we refer to as Suffused. This is a melanin reducing mutation that leaves only a small degree of melanin in the plumage. This should not be confused with 'yellow suffusion' which implies an increase of yellow pigmentation without any melanin changes. When I first heard of the U.S.A. naming decision I thought they were implying the latter term which would be incorrect. But in fact what they are saying is the bird is a suffused mutation. In which case it should not be called 'Suffused Yellow' but Suffused Grey or perhaps Suffused Greygreen. In green based parrot species the 'suffused' naming is used to alter the base color. Therefore we have Suffused Green which is mostly a yellow bird with a light green suffusion, Suffused Blue which is mostly white with a light blue suffusion, Suffused Greygreen, Suffused Grey, etc. The yellow in these birds is not part of the mutation. It is merely being exposed by the mutation removing the melanin pigment. The range of yellow pigmentation varies in them because it varies to some degree in all cockatiels." Dr. Martin has also commented that the mutation sound more like an Edged Dilute – a mutation which exists in Peachface Lovebirds and which could fit for this mutation. Suffused should have even pigment reduction, not edging of pigment.
Frans Kok, a member of the Technical Committee of Large Parrots in Holland with a focus on the cockatiel has asked for Emerald feathers. They will be tested to learn more about the mutation. This T.C. advises the Nederlandse Bond van Vogelliefhebbers (The Dutch National Bird Society) how to act on new mutations. They will issue an opinion based on Emerald's similarity to other dilute parrot color morphs in accordance with the Agreed International System for naming color morphs. The National Cockatiel Society should reconsider their choice in naming the mutation and adopt the A.I.S classification so as to avoid dissemination of inaccurate information and further confusion about the nature of the mutation.
In my capacity as guest genetics adviser for The American Cockatiel Society and as an aviculturist I want to name and classify the mutation in accord with the agreed system. In day to day conversation with my peers however, everyone seems to use the name given to the mutation by its originator. As long as everyone understands why there is a technical classification, no harm can come from using the name Margie thought of when she saw the first baby: Emerald!