September 5, 2026

Understanding Colour Morphs in Cockatiels

How we classify colour mutations now
Old way: sex-linked, recessive, dominant how it’s inherited
New way by Dr. Terry Martin: what the mutation actually does to colour/pigment???

He splits them into 4 main types:

1. Melanin Altering - Grey/Black pigment*
Melanin = grey, black, brown pigment. Most cockatiel mutations are here.
Dr. Martin breaks this into 3:

- *Albinism*: Melanin is _reduced_, not gone.
Ex: *Lutino* - pale eyes, skin, beak, nails + yellow feathers. Also *Fallow, Recessive Silver, Cinnamon*.
Note: Even the whitest Lutino still has _some_ melanin.

- Dilution*: Normal melanin in skin, but less gets into feathers.
Ex: *Emerald / Greygreen / Suffused Grey* - dark beak/feet, but lighter feathers.

- *Leucism*: Melanin production _stopped_ in patches by defective melanocytes.
Ex: *Pied* - patches of pure white/yellow feathers with pink skin/beak in those areas.

2. Psittacin Altering - Yellow/Orange pigment
Psittacin = pigment parrots make themselves for yellow/orange/red. Not from food.

- *Whiteface*: Can’t produce psittacin at all → no yellow/orange, only grey/white
- *Pastelface / Paleface*: Reduced psittacin
- *Yellowface*: 2 types, also reduce psittacin
- *Modifiers*: Like “pumpkin” birds, “golden face” normals. Not official mutations, just more/less psittacin deposited

3. Structure Altering
Changes the feather itself, not pigment.
Cockatiels don’t have a true structure mutation, but you see modifiers:
Sleek birds vs soft, fluffy birds with brittle feathers and light fringes. Probably just wear, not pigment.

4. Pattern Altering
Changes _where_ pigment goes, not how much.
- Pearled / Opaline: Distinctive pattern. Yellow tail, yellow mask, spots/bars of melanin + psittacin.
Ex: Pearled cockatiel. Also seen now in Ringnecks, Lovebirds, Conures.
- Emerald* might also fit here because each feather has a light center + dark edge.

Quick notes from history
1. *80s guide*: _The Encyclopedia of Cockatiels_ by George Smith predicted Whiteface and Albino cockatiels before they existed.
2. *Modern agreement*: Thanks to the internet + writers like *Inte Onsman, Wessel Louw van der Veen, Clive Hesford, and Dr. Terry Martin*, aviculturists now use the same classification worldwide.
3. *Best book*: Dr. Martin’s _Colour Mutations and Genetics in Parrots_ (2002) if you want to go deep.
So basically:
Melanin = grey/black group. Psittacin = yellow/orange group. Structure = feather type. Pattern = where it shows up.