In my little experience...
Once you find them, you need to figure out where they spend some time, sit down and make yourself confortable, your going to be there a while.
It can take a couple hours for the bird to decide to come look at you, If you called once, he knows you are there, If you called twice...He thinks your impatient,..
If you called 3 times he thinks your an impatient bitch....
if you called 4 times and nothing, and you been there for 2 hours, you might as well go find a different spot because he doesn't like you and probably went looking for his girlfriend who doesn't talk so much....
But I am a rookie and am still learning, this is just how they treat me.