Homo floresiensis may have been scavengers rather than skilled hunters
A study of Stegodon bones suggests Homo floresiensis scavenged leftovers from Komodo dragons and lacked the ability to control fire.
Homo floresiensis may have been scavengers rather than skilled hunters
New research suggests that Homo floresiensis, the diminutive ancient human relatives nicknamed "hobbits," may have been scavengers rather than skilled hunters capable of taking down big game or controlling fire. The study, published Friday in the journal Science Advances, challenges decades of assumptions about the cognitive abilities of the small-brained hominins who lived on the Indonesian island of Flores.
Fossils of the species were first unearthed in 2003 at the Liang Bua cave. Standing roughly 3.3 feet (1 meter) tall with a skull the size of a grapefruit, the creature's brain was only slightly larger than that of a chimpanzee. Early discoveries of stone tools alongside the bones of Stegodon florensis insularis—an extinct, bison-size relative of elephants—led scientists to believe the hobbits used tools to hunt these large animals. Burned bones found in the cave further suggested they could wield fire.
Such behaviors are typical of large-brained hominins, including Homo sapiens, Neanderthals, and Homo erectus. This potential connection led some researchers to believe H. Floresiensis was closely related to Homo erectus.
The Komodo Dragon Connection
To test whether the hobbits were actually hunters, Dr. Elizabeth Grace Veatch, a paleoanthropologist at the Smithsonian Institution’s National Museum of Natural History and lead author of the study, conducted a complex analysis of Stegodon bones. Because Stegodon are extinct, the team traveled to Zoo Atlanta in Georgia to observe a Komodo dragon named Rinca. The researchers watched Rinca feed on a goat carcass to understand the specific marks the giant lizards leave on bone.
Using 3D scanning and high-powered microscopes, the team compared the marks from the goat experiment to those on Stegodon bones from Liang Bua. Veatch noted that Komodo dragon tooth marks are shallow and wide, sometimes ending in a fan of striations, while stone tools leave deeper, straighter marks.
The analysis revealed a telling pattern in where the marks were located:
- Komodo dragon marks: Clustered on the meatiest parts of the carcass, such as the hips and shoulders.
- Hobbit tool marks: Found on less desirable scraps, including the ribs and cranial bones.
This distribution suggests that Komodo dragons used their venomous bite to kill the Stegodon, and H. Floresiensis moved in only after the scene was clear to scavenge the leftovers. According to the study, the hobbits were not at risk of venom poisoning because stomach enzymes break down the proteins in Komodo dragon venom.
Questioning the Use of Fire
The researchers also re-examined the evidence for fire. They analyzed rodent bones deposited by roosting owls over thousands of years. If hearths had been used in the cave, underlying bones would show charring.
The results showed a stark contrast between the hobbits and later inhabitants:
| Bone Sample | Findings |
|---|---|
| H. Floresiensis layers (rodent bones) | 0 out of 4,500 (or 4,240 depending on source) bones burned |
| Homo sapiens layers (rodent bones) | Roughly 1 in 5 bones charred |
Out of more than 3,000 Stegodon bone fragments, only one showed signs of fire. Researchers believe that bone, as well as other burned remains found in later layers, resulted from Homo sapiens using the cave starting about 46,000 years ago, long after H. Floresiensis had disappeared.
Evolutionary Implications
The finding that H. Floresiensis lacked advanced hunting and fire-starting skills may shift their place on the human family tree. Dr. Chris Stringer of London’s Natural History Museum said the study reinforces the view that the species is not a dwarfed Homo erectus, but a descendant of a more primitive Australopithecus-like or Homo habilis-like form that reached the island more than 1 million years ago.
Briana Pobiner, a paleoanthropologist at the Smithsonian Institution and study coauthor, noted that this demonstrates the human family tree was not a straight line of linear progress. She added that simply living in groups and remaining wary of Komodo dragons may have been enough for the species to avoid becoming prey themselves.
While some experts, such as paleoecologist Kay Behrensmeyer, suggest it is difficult to fully distinguish hunting from scavenging based on bone features, others, like professor Michael Petraglia, argue the case for passive scavenging is strong. Petraglia noted that the hobbits were "adaptively successful," surviving in challenging environments for nearly a million years.
Veatch is continuing her research to determine if the hobbits consumed other animals to better understand their ecological role on the island.
