On many if not most of the electronic beeper/locator collars, there is a setting that sets off a hawk scream for a locator/on point call. I have one by Sport Dog that has that setting along with a couple of others.
Only problem I have is that the hawk scream scares the hell out of my dog. :shock:
Kind of hard to get her to hold a point when she thinks she has a Redtail on her back. :twisted:
So you know that it is at least a POPULAR method, if the manufacturers are building it into their products, whether or not it is a GOOD method for YOU is another story.
I have used it hunting grouse, pheasant, and even Chukar on one occasion to get birds to freeze rather than run and it has been effective enough that I will continue to try it when the situation allows.