More ideas from NATALIA
Yellow Northern Cardinal - According to bird plumage expert Geoff Hill (Auburn University): This cardinal is yellow because of a rare genetic mutation. The mutation is associated  with fitness costs so it doesn't spread in areas. It arises de nova once in a while.

Yellow Northern Cardinal - According to bird plumage expert Geoff Hill (Auburn University): This cardinal is yellow because of a rare genetic mutation called xanthochroism--which is not the same as Lutino (a form of albinism in birds, fish, and reptiles.