Evolution Earth

[Shane] Food here is scarce, but the biggest challenge is finding water.

[chimpanzee grunting] Jill told us that in the green forests to the south, chimps can get all the water they need from fruit.

No chance of that here in the savanna... and temperatures are already exceeding 104 degrees.

[Jill] These chimps here at Fongoli have to drink, especially if it's a female with an infant.

[leaves rustling] It's really unlikely that she'll go a day without drinking.

[chimpanzees screeching] [Shane] The troop walks for miles to find water... [grunting] and finally reaches a dried-out riverbed.

Hot and tired, it's a last chance... [insects buzzing] but the water looks kind of nasty.

[grunting] You got to be real thirsty to plunge into that.

Mmm.

Nah.

The chimps do have a solution, and it's one Jill tells me is rarely seen anywhere else.

They dig holes beside the water... and the water filters through the sand... [splashing] crystal clear, good enough to drink.