I saw my first Blackbird with white feathers today. I've seen the terms partial albinism or leucism used to describe this condition. I've never seen one before so was very intrigued to find out more about it.
Jean
Nice looking bird and well captured.
Actually, there's no such thing as partial albinism. See this extract from Wikipedia.
The term "partial albino" is sometimes used in the literature, however, it has been stated that "A common misnomer is ‘partial albino’ – this is not possible since albinism affects the whole plumage of a bird, not just part"[16] and the definition of albinism precludes the possibility of "partial albinism" in which a mostly white bird shows some form of melanin pigmentation.
This Blackbird has leucism. There's good explanation of the difference between leucisn and albinism on the BTO website HERE and an opportunity to report it if you want to.