It was raining so I went to move a tarp that was on the ground. When I flipped it over, there was a slug underneath. So I left the tarp where it was to give the slug time to get away. It was gone when I returned, but I'm pretty sure it couldn't have moved that fast and that by being compassionate, I turned the slug into bird food.
Had it been in the open the birds would have got it eventually anyway so good job.
Not sure if magpies eat them but we have them in our front yard nearly every day eating bread scraps and saw one carrying a slug.