Last summer in the South African Journal of Science, faunal specialist Shaw Badenhorst published a short commentary with an interesting question for early hominin behavior: Did they associate with herbivores to avoid predators? His paper is available here: “Possible predator avoidance behaviour of hominins in South Africa.”
Baboons today provide a good example of a defensive strategy using groupings with other mammal species. Together with various antelopes, baboons form multispecies groupings that take advantage of the great vision of the primates and the better smell and hearing of ungulates.
Impalas are the perfect ungulates for primates such as the chacma baboon to associate themselves with during daytime. In addition to their acute ability to sense predators, impalas prefer woodland savanna, rarely wonder more than 2 km from permanent water, and are sedentary, in that they move less than 3 km per day within their home range. During Plio-Pleistocene times, it is possible that hominins such as Paranthropus robustus and Australopithecus africanus as well as other primates associated themselves with ungulates with similar characteristics. The extinct Gazella helmoedi is thought to be an ancestral local form of the extant impala Aepyceros melampus.
Multispecies communities have been studied in many other primates. Still, it is hard to think of ways to test hypotheses about hominin multispecies interactions with fossil evidence.
A key question is the extent to which hominins may themselves have been predators of antelopes and other ungulates. It seems unlikely for impala to have tolerated hominins that were going to eat them at the first hunger pangs.
Many anthropologists assume that hunting or confrontational scavenging became important around the same time that stone tools came into use. Some have emphasized the apparent traces of cutmarks and percussion marks on antelope and horse bones in early archaeological contexts, prior to 2 million years ago. Most assume what seems like a coincidence in time is a correlation: Early hominins started eating animal prey at the same time they started making stone tools.
But there’s an alternative: Maybe hominins were eating other mammals all along. Chimpanzees, after all, hunt a range of smaller mammals, mostly monkeys, but also including duikers and pigs. Whether hominins inherited this behavioral pattern from our common ancestors or not, they were surely capable of hunting in a chimpanzee-like manner.
If hominins were hunters from their origins, we would expect that cutting and percussing animal bones would be part of their behavior as soon as stone tools were invented. Which is what we see.
Still, as the evidence for the “first” stone tools has become earlier and earlier, some archaeologists have poked holes in the argument for early faunal exploitation. Early cutmarks and percussion marks may also be consistent with crocodile predation, as illustrated in a paper by Yonatan Sahle and coworkers (2017). Multiple lines of evidence show that hunting and meat-eating were practiced by hominins at Bed 1 Olduvai sites, after 1.9 million years ago. But that evidence is much weaker for the earliest stone tool and faunal assemblages.
Badenhorst, S. 2018. Possible predator avoidance behaviour of hominins in South Africa. South African Journal of Science 114:13-14. doi:10.17159/sajs.2018/a0274