After a nice chat with the general manager of this park, we're abandoning the owl thing ... he said there's one on the property that the birds use as a perch. He said that the only thing the previous on-site manager found that worked to keep the birds away was a silvery mylar windsock. I found them online and if Steve can't one find here, I'm ordering one tonight!
I'll let you know how it works/doesn't work