chimps use tools to find tubers underground

From this morning's Australian:

[...]
This time, chimps living in the dry woodland savannas of western Tanzania have been caught digging up roots, tubers and bulbs with sticks and roughly shaped bits of bark.

If chimps can forage underground for food, the same may have been true of ancestral humans, hominids, who had similar brain power and hand shape.
[...]

The full text of the article can be found here

Lots of implications for human evolution and the evolution of tool use.

For years I thought that savannah dwelling baboons were a better analogue to our early ancestors as they occupied a similar ecological niche, but now that chimps have been seen spearing bush babies and using sticks to dig for roots maybe being efficient at digging for roots lead them to start exploiting forest margins and then move into open savannah which they could then exploit more efficiently than the ancestral baboons - sticks are probably more efficient than fingers at probing for roots.

This could be neat explanation why a group of forest dwelling apes moved into a savannah based lifestyle, after all there has to be some pressure for the move to take place. It might also explain why our social behaviours can also seem more baboon like than chimp like at times.