Tarzan and the Jewels of Opar by Edgar Rice Burroughs

Mugambi, after his successful break for liberty, had fallen upon hard times. His way had led him through a country with which he was unfamiliar, a jungle country in which he could find no water, and but little food, so that after several days of wandering he found himself so reduced in strength that he could barely drag himself along.

It was with growing difficulty that he found the strength necessary to construct a shelter by night wherein he might be reasonably safe from the large carnivora, and by day he still further exhausted his strength in digging for edible roots, and searching for water.