thanks for the window info! thats exactly how I want to do this, I have to leave them open at night here, its high 90s almost all summer or hotter. But a few weeks ago, I had to cover them because of the cold wind....
I purchased my owl whirly-gig @ a local garden center..........
but you can also purchase on-line.
Here's a link..........(if the 'link' doesn't work, just google "Great Horned Owl Wind Spinner", or go to KitesKitesKites.com. and do a GHO search!)