Classification of colour varieties

Table I

Classification of colour varieties of the Bourke's Parakeet

Eumelanin No extension of red and yellow psittacine

Red P-d factor. Psittacine extension. Inheritance intermediate Yellow P-d factor Psittacine extension. Inheritance intermediate Blue S-s factor Extension of the barbs of structural type Inheritance recessive Yellow pigment and blue structure extension. Dark structure change

Inheritance dominant

Violet structure and dark factor Inheritance co-dominant.
Function change of melanin (M) prod. factors Plumage characteristics . White/brown series (W) Red series (R)

Yellow series (Y) Blue series (B) Green series (G) Dark series (D) Violet series (V)
00 Normal earth-brown plumage white margined wing coverts red margined wing coverts yellow margined wing coverts blue margined wing coverts green margined wing coverts S-s fact. wildtype

S-f fact. wildtype

01 M-o factor Oxidation is incomplete Reduction of melanin granules 50% Inheritance is sex-linked. Whole plumage diluted brown. Eyes dark red

light cinnamon

W-1

. . . . .
02 M-f factor Reduction of amount in the barbs 75%, barbules 50% Inheritance is recessive. Whole plumage diluted. Bright red eyes. fallow

W-2

. . . . .
03 M-r factor Reduction of the amount of grains. 100% in the barbs, 50% in the barbules. Inheritance is recessive. Whole plumage diluted. Psittacine pigments more visible.

brown pastel

W-3

red pastel

R-3

yellow pastel

Y-3

.blue pastel

B-3

. dark pastel

DY-3

violet pastel

VY-3.

04 M-t+ factor Tyrosinase- positive. Inheritance is sex-linked. Eumelanin grains deformed and to small. Inheritance sex-linked.

04 M-t- factor Tyrosinase- negative. No colouring of the grains. Recessive inheritance

White flights and tail, psittacine pigments full visible. Bright red eyes.

Melanin has no effect on the feather colour.

idem

. rubino

R-4

lutino

Y-4

. . . .
05 M-di factor distribution pattern of the pigment production cells is changed. Inheritance is sex-linked. Typical melanin distribution pattern, reduction of melanin in some feather fields. white opaline

W-5

red opaline

rose opaline

R-5

yellow opaline

Y-5

sky blue opaline

B-5

green opaline

G-5

dark green opaline

DG-5

cobalt blue opaline

DB-5

.
06 M-p factor destruction of the pigment production cells. Inheritance is recessive. Feathers are missing eumelanin except in the dark tips. Pied with a regular pattern. Much variance, also feathers with a restricted loss of eumelanin. white edged

W-6

red suffused edged

R-6

yellow edged

Y-6

. . . .
07 M-g factor Shortage of germ cells. Some feathers get no eumelanin. Inheritance is recessive Some feather lacking eumelanin giving a pied plumage, with an irregular pattern white pied

W-7

red pied

R-7

yellow pied

Y-7

. . . .
08 M-ti factor Total increase of eumelanin production. Inheritance is recessive. Dark feathers because of the extra melanin, melanistic plumage . . . . . .
New mutation factors . . . . . . . .

Table II

Combination of colour varieties of the Bourke Eumelanin, no extension of the psittacine Red pigment extension Yellow pigment extension Blue extension blue structure Green extension yellow pigment and blue structure Violet structure
M-factors Effects in the plumage White/brown series Red series Yellow series Blue series Green series Violet series
M 51 Combination of d and o factor. (changed distribution pattern and less oxidation of grains) light rose, equal coloured plumage . rose opaline cinnamon

R-51

. . . .
M-52 Combination of d and f factor (changed distribution pattern and reduction of eumelanin granules) light rose equal coloured plumage . rose opaline-fallow

R-52

. . . .
M-53 Combination of d and r factor (changed distribution pattern and strong reduction of the amount of melanin) light plumage with darker wings white opaline-pastel

W-53

rose opaline-pastel

R-53

yellow opaline-pastel

Y-53

blue opaline-pastel

B-53

green opaline-pastel

G-53

.
M-42 Combination of t+ and f factor (total reduction of the melanin) yellow with white flights and tail . . lutino-fallow

Y-42

. . .
M-63 Combination of p and r factor, interruption of the production and reduction of the amount of eumelanin)

feathers with light brown tips . . yellow edged-pastel

Y-63

. . .
M-65 Combination of p and d factor (interrupted production and other distribution) feathers with light brown tips . apricot edged

R-65

. . . .
M-123 Combination of o, f and r factors (strong reduction and light grains) light plumage (no ino) . . cinnamon-fallow pastel

Y-123

. . .
New combinations . . . . . . .

The classification is adjusted (10 March 2005). New varieties, as dark green, cobalt blue and violet are added. Some abbreviations of names of mutation factors are changed. See the new classification of melanin, psittacine and structural mutation factors.

index menu class. M- factors class. P- and S- factors

Copyright 2003 by Bob Fregeres

E-mail: fregeres@bourkes-parakeet.nl

3/10/05