ALBINO VS LEUCISTIC: Get it right, PLEASE!
I’m not an expert, but this is something that I thought was an easy thing to understand. I’ll put this in Layman’s terms, since I’m not very confident when it comes to genetics.
Everything on the left side is albino. On the right, leucistic. What’s the difference? I can understand the confusion, especially when the leucistic animal has high amounts of white or the photo is obscured/blurry, but the surefire way is checking if you can is the eyes. Red/pinkish? Albinism. Light blue, or whatever the animal’s normal color is? Leucism. Albinos lack melanin, leucistic things just have reduced melanin.
Also, if it has patches of white, it is not albino. HALF ALBINO IS NEVER A TERM YOU SHOULD USE EVER, PLEASE. IT DOES NOT EXIST. Pied, piebald, etc are terms that can used to describe things that have white patches, but they are just forms of leucism (or chimerisim, but that’s another story).
These piebald fawns are disappointed by your former misuse of these terms.
I was reading up on this this morning because I was second-guessing the eye method of telling them apart, and the difference on a mechanical level is that albino animals have an abnormality that prevents them producing an enzyme involved in the production of melanin (albinos still have melanocytes (melanin pigment cells) throughout their body, they’re just non-productive), whereas in leucistic animals there is a defect in the process of migration of pigment cells from the neural crest during development. This defect can be partial or complete, which is why you get the piebald effect.
Albino animals have unpigmented eyes because the melanin in the pigmented retina and iris cannot form, leucistic animals have pigmented eyes because the ocular structures form from a region of the embryo not affected by the mutation.
Albinos may look yellowish in colour rather than pure white, because that’s an unpigmented colour of melanocytes, which are still all through their tissues c:
So yeah, the eye thing is the most solid way to tell them apart, but if they’ve got some colouration (besides widespread pale yellow-ness) they’ve got some sort of melanin being produced and are therefore leucistic.
Edited for mistakes and to add Zoe’s fantastic explination. Seriously guys, tell me when I screw up :3