Piebald robin known for white patches caused by lack of pigment

Why Animals Are Sometimes the Wrong Color

Albino Robin

A Very Unusual (Leucistic) Redtailed Hawk – Foothills Clusters Wildlife

Is an Albino or Leucistic Robin Rare? - Birds and Blooms

Some really cool coloring! : r/DOG

NYS Department of Environmental Conservation - Have you ever seen a bird with white or faded patches of feathers, mixed in among its normal plumage, like our little American Robin friend, here?

What's in a name? Nomenclature for colour aberrations in birds reviewed

Albino Robin

Great Plains Connections: What Is That White Bird? •Nebraskaland Magazine