Guard llamas can protect goats, sheep, alpacas, and sometimes poultry.
Most guard llamas should more accurately be called sentry llamas. My Maxine’s job is to keep a sharp eye on the surrounding woods (the goats have sharp senses in their own right but they are not nearly so alert), to give the alarm at sight of danger (they whinny loudly), to herd the goats away from the danger, to round up strays, to stand between the herd and danger, to mark their territory (llama smell discourages the presence of predators), and to look big and weird to confuse predators about what the herd is.
Some llamas will go the step further and attack marauding dogs – they have a natural hatred of canines and have been known to stomp aggressive dogs to death. But they should not be expected to take on a pack of coyotes or a bear or mountain lion – for that one needs livestock guardian dogs. Llamas are very intelligent and, despite their aversion to dogs, can learn to work together with LGDs to protect the flock – llama on defense, LGDs on offence.
Not all llamas have the temperament to be guardians; some become annoyed by their charges or aren’t very watchful. The event that showed me Maxine is an excellent guard llama was a month or so back. Our dog – not an LGD but a good farm dog – alerted to something in the woods and ran down to investigate. A minute later we saw her being chased back towards the house by a young black bear. The llama and all the goats were down in the pasture, maybe half a football field from the bear. The llama immediately herded the goats up to the barn, came back and rounded up the two that strayed, stood between the barn and the field for a good ten minutes after the bear was gone, then came back into the field and marked her territory. We were VERY impressed.