Archaeological investigations at the Haida Gwaii archipelago, off British Columbia’s north coast, have shed new light on the interactions between early human settlements and the post-glacial environment in the region.
Around 15000 years ago, the Hecate Strait, that now connects the archipelago to the mainland, was a ‘wide, grassy plain.’ Since much of the old coastline is now submerged, the team of Canadian archaeologists targeted karst (limestone) caves for their investigations.
These caves housed a lot of animals that are no longer present in the region and provided ample food resources for humans. The fossil record at the three cave sites examined in the archipelago dates to ~14690 to 11000 years before present.
The findings now confirm human occupation at Haida Gwaii to at least 12600 years ago. Dates were obtained by radiocarbon dating bone and charcoal samples across the target sites.
Three caves were subject to archaeological investigations in the entire cave complex. One cave, named K1 in Moresby Island, yielded bones of the black and brown bears, caribou, deer, and a few remains of fishbone, mouse, songbird. Examinations of bone taphonomy revealed a considerable amount of carnivore impact, like tooth puncture, gouge marks, spiral fractures and crushing.
Researchers also recovered remains of spear points from K1 cave, but ‘the absence of butchering tools or waste flakes suggests these artifacts may have been brought in by wounded bears that pulled them out in the safety of their den, or eventually died in this deep passage with the points still in their bodies.’
Faunal remains recovered in cave Gaadu Din 1 are largely similar, with the addition of the domestic dog. “Using DNA analysis and radiocarbon dating, the team determined the dog that lived 13,100 years ago — the oldest evidence of domestic dogs ever reported in the Americas. What’s more, dogs are “a proxy for the presence of humans,” one of the authors Quentin Mackie told Hakai Magazine.
Bones in this cave too bear similar marks of carnivore action, and authors maintain that ‘the cave was used by large carnivores (e.g., brown bear) for predation on other bears’ or other animals. Archaeological features here were slightly different: stone knives do indicate some butchering activity. The entrance of the cave also consists of a hearth feature that establishes human use.
The third cave – Gaadu Din 2 – was poor in bone finds, but was relatively abundant in stone tools, which ‘reveals the cave was intermittently used by people as a hunting camp or refuge’ 12000 to 10000 years ago.
The authors note that the presence of the brown bear indicates the survival of the species after the last glacial period in refugia specific to the region. The study adds the Haida Gwaii-Hecate Strait sector along with Beringia could have been an ecological niche for this particular brown bear clade as well as humans.
While historical records say that deer were introduced to the island by missionaries at the beginning of the twentieth century, a very thin separation between the mainland and the island around 13.5 kya that enabled deer movement might explain the evidence of deer bones found in the archaeological context. A colder and wetter period between 12900-11700 years ago might have led to the extirpation of the deer, for the species disappears from the archaeological record around this time.
These palaeoecological investigations highlight that the flora and fauna of the area were much different back in the day and that people with coastal adaptations had begun colonising the region by 13500 years ago. Equally importantly, the study highlights the potential cave sites offer for archaeological discoveries in the region.
– The author is a freelance science communicator. (mail[at]ritvikc[dot]com)