These apes use gesture language for referencing,

and it was partially deciphered.

http://www.bbc.com/news/science-environment-28023630

http://phys.org/news/2014-07-decode-gestures-chimpanzees.html

http://www.biologynews.net/archives/2006/03/21/referentialgesture_communication_in_wild_chimpanzees.html

http://www.eurekalert.org/pub_releases/2006-03/cp-rci031606.php

http://www.newscientist.com/article/dn11756-bonobos-and-chimps-apes-speak-with-gestures-.html

http://ns.umich.edu/new/releases/178

http://www.eurekalert.org/pub_releases/2006-03/uom-ysm032106.php

Regards,

Joachim

Dear Goran, What do you mean by conceptual metaphors? Do you mean Halliday's Ideational (experiential/conceptual) metaphors or Lakoff's and Johnson's conceptual metaphor? Elaborate please.

If you mean conceptual metaphor or cognitive metaphor in cognitive linguistics, you can find the following links helpful which is a study about Chimps:

http://en.wikipedia.org/wiki/Conceptual_metaphor#Conceptual_metaphorical_mapping_in_animals

http://elifesciences.org/content/2/e00932

Thanks for interesting links. I refer to conceptual metaphors as elaborated by Lakoff and Johnson and others. Chimps and bonobos surely use  gestures for mainly indexical  reference in their communication, but sofar there is no evidence of use of symbols or displacement (temporal or spatial) referential gestures. Conceptual metaphors (among us Homo Sapiens normally manifested in linguistic metaphors) might be an interesting  greyzone between online and offline thinking and communication.

There are some mentionings of a gorilla named Koko.

Koko seems to be able to invent new symbols by

stringing known ones, in a semantically reasonable

manner. For example water-bird for swan or duck,

drink-fruit for melon, and animal-person for

gorilla.

http://www.princeton.edu/~achaney/tmve/wiki100k/docs/Koko_%28gorilla%29.html

Regards,

Joachim

There's a recent paper on spatial referential gesturing in bonobos: http://www.cell.com/current-biology/abstract/S0960-9822(14)00666-6