This last weekend NE Texas was open for doe as well as bucks so I took my ecaller with fawn distress sounds out and Saturday morning I saw at least one coyote (either saw it two times or saw two) and at the very end of the sequence a bobcat. Unfortunately my step-son had taken the rail off the tripod stand I was on and I couldn't steady my rifle long enough to get any shots. So, yes, fawn distress calls do work on varmints.
cb