Raul senses a bear and makes a llama "alarm call" in the YouTube video.
What is a Llama Alarm Call?
A llama may make an "alarm call" when the llama is feeling threatened or startled by something . It is a loud, high pitched rhythmic sound. Being herd animals, this call is used to alert the others in the herd when one spies a predator.
In the wild, llamas travel in herds. When one of them spy a predator they make an alarm call to warn others. That is very comforting when you are hiking or camping in bear country. The llamas will warn you when a bear is around.