I used to use an owl call 30 minutes prior to legal shooting when I first get to a property. I stopped worrying about how dark it is anymore and now primarily use a crow call at any point I need to located them. I use to think it didn't make sense to use a crow call so early, but now I think that was over-thinking what goes through their little brains. I've never had them stop responding due to over use, but I usually only use it to initially locate them and then again sometimes to see if they've flown down.

Mike