Originally Posted by epo
The male is a normal light green( with a large amount of opalescence) split to blue and to opaline as we can see from the chicks ...
The female is an opaline goldenface or YF2 dominant pied!
I'm not a mutations expert but ...
I think the cock bird is normal light green split to opaline and the hen is probably golden face or YF2 opaline single factor dominant pied cobalt.
All the chicks will be light or dark green unless the cock bird is split to blue.
Dominant pied is dominant to normal. Since the hen is single factor dominant pied, 50% of the chicks will be dominant pied (or opaline dominant pied) and 50% will be normal (or opaline). (If the hen were double factor dominant pied, then 100% of the chicks would be dominant pied.)
Opaline is a sex-linked gene located on the Z chromosome, and it is recessive to normal. Male budgies have two Z chromosomes (ZZ) and female budgies have one Z chromosome and one W chromosome (ZW). Consequently, to be visually opaline (like your hen), a male budgie needs two opaline genes whereas a female only needs one opaline gene. A male budgie with one opaline gene is visually normal (like your cock bird).
Chick #1 is normal, as indicated by the black and white wing pattern and grey down.
Chick #2 is opaline, as indicated by the white down. White down also can indicate recessive pied; however, both parents would have to be split to recessive pied in order to produce a recessive pied chick. Since this chick is visually opaline, your cock bird must be normal split to opaline.
As for your cock bird's unusual appearance, I recommend you take him to an avian vet: www.aav.org/search