NOTES: Recordist's announcement at beginning of recording: Orangutan is solitary primate. vocalizations in this recording occur in rather limited circumstances; either in a competitive territorial context between adult males; or in agonistic and fear contexts with human observers. Most spectacular of orangutan vocalizations is adult male long calls. These are loud prolonged location calls given by adult males to produce spacing from the other adult males in a territorial-like context; and also a few observations indicate that they serve to attract receptive females to the caller. this recording is a near complete call of a full adult male Bornean orang-utan. The call commences with a bubbly introduction, then a series of loud groans, and then tails off in a rather bubbly prolonged tail off.