The thing about alpacas is that they are a deterrent against predators, not protection against predators. Alpacas have no way to protect themselves or the chickens against an attack from something. Their only defense is to run or to stomp, and they don't do a very good job at the stomping part. Just google alpaca dog attack and you'll get the idea. Donkeys do a much better job at protection. I actually wanted to get a miniature donkey to protect my alpacas but my husband said no.
That being said, I have no problems with foxes, coons or possums on my farm. They don't go after alpacas and I do believe that the alpacas being in the barn with the chickens keeps the predators out. It isn't the alpacas per se, but the fact that there are larger animals present that discourages predators. I also have 5ft no climb fencing surrounding my pasture but if coons wanted to get in bad enough they could breach that.
Also, have you considered that you will have to provide shelter and buy hay for the alpacas? They don't eat a lot, but hay isn't cheap.
That being said, I have no problems with foxes, coons or possums on my farm. They don't go after alpacas and I do believe that the alpacas being in the barn with the chickens keeps the predators out. It isn't the alpacas per se, but the fact that there are larger animals present that discourages predators. I also have 5ft no climb fencing surrounding my pasture but if coons wanted to get in bad enough they could breach that.
Also, have you considered that you will have to provide shelter and buy hay for the alpacas? They don't eat a lot, but hay isn't cheap.