squirrel and apple

Today I was watching out the window as a squirrel tried to steal my single apple from my little Fugi apple tree. I have a knee-hi over the apple to protect it from apple maggots. What to do to protect from squirrels?! I banged on the window and chased him off twice. He didn't come back by nightfall, but I think he will very likely find a time when I am not standing by and guarding my tree. I don't think it will be ripe enough for me for another month yet.

The real problem is having only ONE apple on a tree! It doesn't bloom much since the big Norway maple in my back yard is shading it more every year. The apple tree is small (a dwarf) but too big to move. Maybe the maple will fall down some day.