What are those big dead spots on and around #18 green?

You've probably seen some dead spots on and around #18 green about the size of your hand. They come from our winged friends that resemble a prehistoric Pterodactyl- Blue Herons. I don't mind having the Herons around except when they leave a mess on the green. During warm weather, the Heron urine kills the grass. It's been cold recently, so I decided to see if their recently left presents could be cleaned up.

This is what the fresh deposits look like. I figured some extra water and a quick scrub job might work.

A quick rinse, and we'll see in another week or so if it works.