Bones in Cave Walls

In a paper on paleolithic cave art Jean Clottes said: ‘Among the most mysterious remains are the objects deposited in the cracks of the walls and in particular the bone fragments stuck forcibly into them.1

The question that I have is:

Has anyone considered the possibility that some of the objects were placed there to act as a warning of possible collapse? Limestone structures are easily eroded by water, and therefore prone to collapse. Could a change in the size or shape of a gap, or the sound of a cracking bone have given our ancestors a warning which allowed them to escape from danger?


Note: 1. Jean Clottes, 2002: Paleolithic Cave Art in France p. 7, Human and animal activities in the deep caves: Bradshaw Foundation: Accessed: 12 September 2013