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During 8 years, 1986-93, 10 complete and one partial (primaries) albino chicks occurred from the nests of presumably the same pair of Corvus corone. The parents were normal black and buff-mutant birds (confirmed by the junior author and his friend). They nested in a red-pine wood, renesting in different tree every year. The brood size was four chicks (at least confirmed in one year), including one (two in two years) albino bird. Thus, the total chicks produced are estimated as 32, consisting of 22 normal and 10 albino (incl. of a partial albino) chicks. It is suggested that the both parents had a recessive albino gene, as totally recessive in one and semi-recessive in the other (buff-mutant) parent. The occurrence rate of an albino gene is biologically very low and so, the pairing of such mutant individuals is of extremely rare case. As far as known complete albino didn't occur in C. macrorhynchos, all reported (at least three) cases having been buff-mutants, while total (or complete) albinos have occurred in C. corone and no buff-mutant has ever been reported (so, the buff-mutant parent bird here reported is considered to be rather exceptional). The buff-mutant may represent weak defficiency of melanine pigments or its activating enzyme, the tyrosine. The other probability of the buff-mutant of being the F1 between a normal black and an albino parent is highly unprobable, because the albino itself is of very rare occurrence. Moreover, albino chicks here reported had dropped down from the nest before fully grown, probably not enough fed by the parents. So, survival rate of albinos to its maturity and their possibility of mating with normal bird should be very low. However, albino fledgling and grown individuals have been reported from three localities some kilometers north and south of the nest sites. Therefore, albino genes may be recessively retained in this locally segregated (by mountain ranges) coastal population of Curvus corone, with some consanguineous-marriage effect.

Occurrence of Albino Chicks from Presumably the Same Pair of Corvus corone, during Contiguous Eight Years.