Study Lends New Support to Theory that Early Humans were Scavengers

In a very real way, it may have been the lion and the long-extinct sabertoothed cat, not the dog, that was ‘man’s best friend’, if we go back far enough into human prehistory.
In a recently published study in the Journal of Human Evolution, author and paleoanthropologist Briana Pobiner of the Smithsonian Institution’s Human Origins Program shows that it was entirely feasible for early humans living on the African savanna as much as two million or more years ago to acquire enough calories simply by lying in wait and scavenging the remains of prey left by lions or big sabertoothed cats after they finished eating the first cuts.
She concluded this after spending several months in Kenya’s Ol Pejeta Conservancy nature preserve observing, examining, and analyzing large carnivore kills scattered across its grasslands. According to Pobiner, even though it is a modern landscape and environment, it isn’t much different than some of the landscapes that early human ancestors inhabited millions of years ago.  
“The site is a great analogue for the kinds of African savanna environments where hominins are thought to have lived,” said Pobiner. “The habitats—both types and varieties—were probably similar, and in this particular place, lions were the dominant predator. This may have been very much like past carnivore communities during the time our ancestors were starting to eat meat from larger animals, when we have evidence that felids—ancient lions, leopards, and three species of sabertoothed cats—lived alongside our ancestors and may have been the dominant kinds of carnivores at this time.“ She points to ancient sites such as Koobi Fora and Olduvai Gorge in East Africa that have yielded evidence of the earliest stone tools, with ancient environments very similar to that of present-day Ol Pejeta where big felids coexisted with humans.
A typical day in the field for Pobiner would begin with listening to a short wave radio for any mention from the conservancy about spotting lions or hearing them roar during the night—particularly if they were eating prey. On a lucky day, she would drive her Land Cruiser along with an armed guard out to the lion site and then simply stop to observe them at a safe distance while they ate. The armed guard was critical. "I didn't want to become prey myself—to be charged by an elephant, rhino, buffalo, or other angry ungulate," she said. About one hour after the lions were done and had left the scene, she and her assisting guard would finally approach the kill, meticulously document the remains with photographs and notes, and then pick up the carcass and place it into the back of the Land Cruiser. Later, another assistant would carefully remove the meat from the bones with wooden tools so as not to make any marks that might be confused with tooth marks, and then boil the bones clean. Once the bones were dry, they would be ready for further study.
Apart from potentially angry ungulates, the work was not without other challenges.
“It turns out lions don't kill things all that often,” Pobiner says. “So getting a large enough sample size was challenging. Another challenge was sometimes having difficulty getting around to get to the carcasses even with my sturdy vehicle during the rainy season when it got really muddy or if I inadvertently drove into a warthog burrow.”

http://popular-archaeology.com/issue/winter-01012015/article/study-lends-new-support-to-theory-that-early-humans-were-scavengers