Leucistic Blackbird b+w or brown or?

[Stapey]

Wonder if your guys could help me, I'm assuming the leucistic ones are the b+w ones or all white with normal coloured eyes as that's what I'm used to in the reptile world and that the lighter brown blackbirds are not leucistic but a different colour mutation. Just confusing as I've seen people say the lighter brown oens are the leucistic but that goes against what I know? If anything the browns ones are what the reptile would would call hypo.

[Dogghound]

Do you have any photo's? Your description is about right for leucistic blackbirds i.e ones which show white but are not true albinos.

When you say brown ones you dont mean females do you?

[Stapey]

Nope, they are just an incredible light colour brown which some website says are the true leuscictic, not the b+w ones.

Second and 4th image here are the ones I'm on about, they must be a colour mutation.
leustic blackbird - Google Search

[Dogghound]

Interesting, almost erythristic, never seen them like this. Leucism can affect one feather or the whole bird, there is no true or not true form. I have a blackbird in my garden with a white alula feather on one wing this can be descibed as leucistic as could a blackbird that is pure white, they are just different degrees of it. Leucism is simply where pigmentation such as melanin is not properly formed within the birds feather.

[RoyW]

Contrary to popular belief, an all white animal/bird is not necessarily an albino - and true albinos are not necessarily white.

The pale brown Blackbirds in your link almost certainly can be correctly called 'leucistic', as can the individuals which are partially white, or all white but with dark eyes.
Leucism means nothing more than a reduction of pigment, but generally affects the production of all pigmentation in the skin/fur/feathers (of the whole organism or just part of it). The pigmentation may be absent, or at a reduced intensity, so appearing washed out or pale.

Albinos, on the otherhand, are unable to produce any melanin - but may produce other pigments as normal. This means that they invariably have pink eyes (the red colour of the blood shows through), whereas leucism typically affects only the colours in the skin/fur/feathers.
Pigments other than melanin may still be present in true albinos, so they can have (for example) yellow or red pigmentation.

[RoyW]

Originally Posted by RoyW

The pale brown Blackbirds in your link almost certainly can be correctly called 'leucistic', as can the individuals which are partially white, or all white but with dark eyes.
Leucism means nothing more than a reduction of pigment, but generally affects the production of all pigmentation in the skin/fur/feathers (of the whole organism or just part of it). The pigmentation may be absent, or at a reduced intensity, so appearing washed out or pale.

This is the typical usage of the term "leucistic" anyway, although after a bit of a web search, it seems that there may be a far stricter medical usage of the term which limits 'leucism' to a condition affecting the skin, which prevents pigments from being deposited. With this definition, birds and mammals which have normal coloured skin, but which have genetic, or other, problems which prevent pigment being deposited in hair or feathers are not leucistic. It all depends how precise you want the definition of the specific problem causing the abnormal colouration to be (with this medical definition for leucism it may be that neither the all white Blackbirds, or the pale brown Blackbirds are actually leucistic - and the partly white ones certainly are not).

[Stapey]

Ah ok thank you guys, just gets so confusing! I wondered why since the reptile world have lots of classes and types for anything how the common blackbird has no true or universal name for the different colour mutations that exist. Although I guess no-one keeps black birds as pets really and the mutations specially the whiter ones may not live that long in the wild. Beautiful though.