Scientists have never really been able to explain why Neanderthals died out 30,000 years ago, but John Fa at the Durrell Wildlife Conservation Trust in Trinity, Jersey (a British Crown Dependency just north of Normandy, France) thinks that the rise of the rabbit population gave humans an edge, which eventually led to the Neanderthals' extinction.

Experts claimed in 2009 that Neanderthals weren't sophisticated enough to catch birds and fish, but were proven wrong in 2011, when researchers found traces of fish scales and feathers on stone tools. There was also evidence that they wore jewelry and processed wood and hides, which contradicts the idea that they didn't have the sophistication to carry out subtler tasks.

So what's the difference between the former and latter? We already knew that Neanderthals were clever hunters, able to successfully hunt down dolphins and seals. Large animal remains were fairly abundant in caves, but 30,000 years ago, rabbit remains became more common, NewScientist says. This timing matches the Neanderthals' extinction.

John Fa and his colleagues hypothesize that humans were better able to cooperate, surrounding rabbit warrens and driving them toward hunters with fire, smoke or dogs. Fa said it's not clear why Neanderthals would have more trouble with rabbits, but there's a possibility they could not make the switch from hunting big game. But Bruce Hardy, a researcher at Kenyon College in Gambier, tells NewScientist that Fa could be taking his hypothesis too far. While humans could have eaten more rabbit, neither species would have exclusively eaten meat.

More likely, Neanderthals died out for a variety of reasons, not any major single one. Just like the dinosaurs, who were close to extinction already after rapid climate change and an enormous volcanic eruption before the asteroid collision that pushed them over the brink, the coincidental timing of the rise of the rabbit with the disappearance of our cousin species could just be one small piece of the puzzle.

Fa plans to study the isotopes found in hominids in the region next, as there could be key differences in their bones depending on diet.