In caves on the Indonesian island of Sulawesi, ancient peoples marked the walls with red and mulberry hand stencils, and painted images of large native mammals or imaginary human-animal creatures.
These are the oldest cave art sites yet known or at least the oldest attributed to our species. One painting of a Sulawesi warty pig was recently dated as at least 45,500 years old.
Since the 1950s, archaeologists have observed these paintings appear to be blistering and peeling off the cave walls. Yet, little had been done to understand why.
So our research, published today, explored the mechanisms of decay affecting ancient rock art panels at 11 sites in Sulawesi’s Maros-Pangkep region. We found the deterioration may have gotten worse in recent decades, a trend likely to continue with accelerating climate change.