See video. 130 pant-hoot 131 pant-hoot Goodall: Series of long calls which are often contact calls between distant groups or calls given by chimpanzees at night, from their nests, when they are within earshot of another group give pant-hoots when they arrive at a food source, cross a ridge, or face into a new valley. A subordinate greeting a dominant often gives pant hoots and pant grunts Higher-ranking males pant-hoot more often than lower-ranking ones. Chimpanzees advertise their presence and numerical strength to rival groups. At Mahale adult males also pant hoot when agonistic confrontations are continuing, in which pant hoots function as vocal threat. Pant-hoots have four stages: introduction, build-up, climax and let-down, but females lack climax and let-down stages. Elements of pant-hoot calls vary between Mahale