My chickens are locked in a very large chain link kennel with bird screening over it. I have not had any problems (knock on wood) with predators except rats. I have several dogs who keep the coyotes away. I put shape tarps over the top of the kennel so even in summer, they have shade. I have plants growing around the outside of the kennel that provide more shade, and because the plants are very "sappy" they help keep the air cool for the birds.
Great Pyrenees dogs are great at protecting farm animals. I have 2 pups, one is 12 weeks old and her sister is 9 months. Both are very gentle and protective of the birds.
Llamas are good, however I wouldn't trust them to protect birds. Plus I don't see them taking on a pack of coyotes. There have been several cases of them being killed by a couple of domestic dogs, so they would no match against a pack of wild dogs. You'd have to have more than 1 or 2 for that. I would be very suspicious of believing the story of 1 llama littering the pasture with coyote bodies. I asked a friend who has llamas and they just rolled their eyes and laughed.