Domesticated dogs may have worked with ancient humans to kill mammoths.
Sites containing human tools and scores of mammoth skeletons became common in eastern Eurasia sometime between 15,000 and 45,000 years ago, a Penn State Science news release reported.
"One of the greatest puzzles about these sites is how such large numbers of mammoths could have been killed with the weapons available during that time," Penn State Professor Emerita Pat Shipman said in the news release.
The researchers found that "few of the mortality patterns from these mammoth deaths matched either those from natural deaths among modern elephants killed by droughts or by culling operations with modern weapons that kill entire family herds of modern elephants at once," Shipman said.
The research team believes some of the large canines found at the site were not wild wolves as was previously believed, but rather domesticated dogs. The researchers looked at how hunters work with dogs to test predictions about the history of the site.
"Dogs help hunters find prey faster and more often, and dogs also can surround a large animal and hold it in place by growling and charging while hunters move in. Both of these effects would increase hunting success," Shipman said. "Furthermore, large dogs like those identified by Germonpré either can help carry the prey home or, by guarding the carcass from other carnivores, can make it possible for the hunters to camp at the kill sites." Shipman said that these predictions already have been confirmed by other analyses. In addition, she said, "if hunters working with dogs catch more prey, have a higher intake of protein and fat, and have a lower expenditure of energy, their reproductive rate is likely to rise."
The sites contained other hunters such as foxes. Competition between predators can get nasty, and if the humans were using dogs to hunt they may have focused on killing off wild wolves.
A past study found the diets of the dogs believed to be domesticated had different diets from the wild wolves. This could indicate that they were fed by humans.
Analysis if mitochondrial DNA also showed the domesticated dogs had a different genetic signature than those believed to be wild.
"This finding may indicate that these odd canids did not give rise to modern domesticated dogs and were simply a peculiar, extinct group of wolves," Shipman said. "Alternatively, it may indicate that early humans did domesticate wolves into dogs or a doglike group, but the rare mtDNA lineage was lost over time."
