Ok, that I have a problem with because there is a difference between leucism and albinism. Leucism is when a bird/mammals have some defect in producing melanin (color pigments, namely black) so it can result in a blotchy white body or dilute/washed-out look but they can still produce it. Albinism is an organism that cannot produce melanin at all and hence why they are completely white or cream colored. And it annoys me all the time when someone mislabels an leucistic. And as I’ve told others in the past, it’s like calling leukemia and myeloma one and the same. Yes they are both blood cancers but they effect the body differently.
I like this post explaining why leucism can be a misleading term. https://www.facebook.com/groups/387147351626014/permalink/950092765331467/
I’m in denial.
Can you explain this, please?
I linked the post in the next message, you can read about it there.
It’s a fact that no mutation in birds called leucism, as well as mammals, the term is known from non-bird reptiles and it’s not fully understood right now what causes the condition (it can appear to be a known mutation).
Can you provide some kind of bibliography about this?
The link has it, and as I remember your link was discussed in group, I know that Audubon society uses the term, though it’s still wrong, at least in a scientific, genetical way. I can check for more links when I’ll get back home.
I only saw your link to facebook after my reply. I would still appreciate if you provide some more info about this matter.
I rest my case!
“Albinistic birds have pink eyes because without melanin in the body, the only color in the eyes comes from the blood vessels behind the eyes.”
Do you realise how wrong this is?
Talking scientifically leucism means certain conditions in reptilians, like well known white crocodilians, in the meantime the term is widely used for anything that is not albino in vertebrates (though it also leads to confusion as many albino looks ok to call leucistis for ordinary person). If we want to do things right we should call mutations their names, not a word that was chosen by pigeon breeders. Most conditions that are called leucism by ppl turn out to be neural crest disorders like progressive depigmentations or piebaldism, dilute, other genes mutations etc. How can you call that a leucism if those are having completely different base?
“A genetically complete albino could still have highly colored feathers if a pigment other than melanin were present… leucism is caused not by a lack of pigment, but by a reduced deposition of pigment in the feathers.” – Rosenberg 2006
That’s why you have yellowish (xanothophyll) albinos and other variants because just melanin is present. Leucism is complete lack of color pigment. And if you notice, there’s a much higher amount of “leucistics” than abinos and I think it’s a nod towards having it be a different condition. But I guess this situation is just the same with birders in terms of morph or phase or basic or summer plumage.
Read my last comment, leucism is a made-up term, like polyphyletic group, but for colour abberations, that’s why it should be avoided, as it leads to confusing, making ppl think it’s all the same.
(recommented to retain the original order)
Yeah, sorry, I saw your post only after I sent the comment.
There’s another example, term xanthrochromism, it describes the phenology of the bird, but not what causes it, so there’re two views - first it’s easier to use the term to describe the phenology, or the second, scientific one, to call each condition the name it has or the name of the gene it involves or call it with not a term, but a describtion what is happening with the bird that won’t lead to confusion of another person who’s not into the theme.
And sure, read https://veterinaryherpetologist.blogspot.com/2009/08/leucism.html?fbclid=IwAR3pMLx4cx4NYA8vyThaHTBovlAVRz0ZCunzVUzCMEoAhMgWz2KD6CsS1GI
Can you explain this one? Trumpeter Swan deemed a leucistic because the bill is pink, eyes dark (and I know you hate that feature) but seriously, would you call it an albino?
In Mute Swans it’s Oca4/Slc45a2.
So it sounds like to me that just like with identification on iNaturalist, you can group pigments and aberrations of those pigments into larger groups. So one might call a yellow cardinal “CYP2J19” and it’s the most accurate id, however it’s just as acceptable for person who doesn’t have the experience to just call it “xanthrochromism”.