Meaning and ostension in great ape gestural communication

It is sometimes argued that while human gestures are produced ostensively and intentionally, great ape gestures are produced only intentionally. If true, this would make the psychological mechanisms underlying the different species' communication fundamentally different, and ascriptions of meaning to chimpanzee gestures would be inappropriate. While the existence of different underlying mechanisms cannot be ruled out, in fact claims about difference are driven less by empirical data than by contested assumptions about the nature of ostensive communication. On some accounts, there are no reasons to doubt that great ape gestural communication is ostensive. If these accounts are correct, attributions of meaning to chimpanzee gestures would be justified.