I believe the OP, might have been some else, asked if feral cats could be called.
well.... about 30 minutes ago (2:10PM) I was "messing" with the wife as she was leaving for her Mom's. I was blowing a coaxer at her making kitty kat meows and blowing some little birdy tweets. Then I went to blowing some bird distress while trilling my tongue.
As she was pulling out of the driveway, I saw something out of the corner of my eye and turned to see a feral cat hauling buggy straight for me. I froze and shut up so maybe it wouldn't associate the sound with a human and I will be able to call and remove it later this evening.
Total time of me blowing on the call was probably less the 45 seconds.
So, as I stated earlier you CAN call feral cats with a predator call. Try it. I have done it numerous times and it's almost as much fun as calling in a coyote. Especially, when one comes running to the call like that one just did.