In the open country I call coyotes in if I waited with 15 minutes of silence at the end of my calling stands that I hear coyotes off in the distance I would make quite a few less stands during that day. I have way more coyotes show up in less than 6 minutes than I have show up after 10 minutes of calling.
Quite a few of the coyotes I call in with prey sounds show up with their hackles up and are ready to fight. So I believe that the coyotes that show up with their hackles up think the prey sounds I am playing are caused by other coyotes. On quite a few calling stands I make I get coyote vocal responses as soon as I play a bird, rabbit or rodent sound.
The coyotes in the below pictures all came in to prey sounds and looked like they were ready for a fight.
IMG_4362 by
Robert Morris, on Flickr
IMG_3328 - Copy by
Robert Morris, on Flickr
IMG_0859 - Copy by
Robert Morris, on Flickr
IMG_0606 - Copy by
Robert Morris, on Flickr