Cindi, I had that situation within days after I got my pond finished and had added fish. We had a heron visiting the local large ponds in the area, rural area, lots of people have the large ponds on their land, some for cattle, or just fish. We used to think it was pretty to see that big bird sore down and fish in the ponds. But, when I got up kinda early, just after daylight one morning and looked out back, I saw that big thing at my fish pond, not so pretty anymore. I had to get up early every day to keep him away. Since I am home all the time, I could keep an eye out for him. I ordered one of those decoys, its very realistic, got it from the pond store within 2 days. He has never tried to land again, flys over but goes on down to the neighbors regular dirt pond. Cost was about 29.00. Supposedly they are territorial and won't land if another bird is already there. I will attempt to add in a picture of my Heron visitor. Good Luck