Bird droppings on outdoor orchids

[wjbrown]

Should I do something about the bird droppings that appear on my outdoor orchids? Cattleyas, oncidium, Denphals, etc. Some are growing on the tree, others are in pots with bark. I water once a week and mist once in the dry season (four months) and it usually rains every day or so in the wet season.

Should I wash them off? Keep them from getting onto the potting medium? Ignore?