I have a rooftop deck on my house. I put up some wooden poles to hang some lights on and after my first summer with the poles up they were all covered in bird p

I have a rooftop deck on my house. I put up some wooden poles to hang some lights on and after my first summer with the poles up they were all covered in bird poop. It's not a problem here in the winter when it rains enough that the poop washes away but we can go weeks or months in the summer and the accumulation of poop can smell bad. Some bird spikes on the top of each pole has mostly solved the problem.