:)I think this question might need a couple answers. In a place like the capitol forest and lots of other places I have noticed something.
In CF I might call for 10 minutes or 30, but I will likely sit for 10-30 minutes before I call at all. Even when you sneak in you disturb things, I do not find that nature has a very long memory in this case. If I sneak in, sit for a while to let things chill out, then call, my percentage goes up, also I sometimes get watching something, taking a nap or some other diversion and find that sometimes that extra time spent raises my %.
How long one calls may not relate to how long one stays on a stand is what I am trying to get at.

Carl