The Yautja do not call themselves "predators." Yautja, when translated, is both the singular and plural form of the word hunter/hunters.
Dr. Bergstrom theorized on the origins of the Yautja, while an unnamed government agent (possibly from OWLF) attempted to suppress any knowledge of it. She believed that the Yautja she met in Yellowstone was on a pilgrimage to earth, driven by instinct to return to its species world of origin.
Dr. Bergstrom went on to assume that the Yautja descended from primitive mammalian precursors called Therapsids that had somehow been taken away