I caught my tortoise eating bird poo in the garden. I'm sure it isn't part of a nutritional diet but will it be of harm? There isn't a lot I can do to prevent the odd bird pooing in the garden.
I once asked my vet why my dogs loved to eat dry dog and cat poo when they found it. He said because they needed magnesium. Birds use Ariza's water platter and sometimes leave their droppings. I've seen her eat them sometimes and have wondered if she does it for a reason. I'm sure animals know more about their own body's needs than we do. I tend to trust her instincts.