Today I learned about 'rabbit starvation' and how Neanderthals avoided it.

When you're a hunter-gatherer and it's winter, you may try to survive by eating only meat - like rabbits, but also deer and other game. But this gives you too much protein and not enough carbohydrates and fat: most of this meat is very lean. If you eat enough lean meat to get all the calories you need, you can die from an overdose of protein! It's called 'protein toxicity'.

Hunter-gatherers in this situation sometimes throw away the 'steaks' and 'roasts' - the thighs and shoulders of the animals they kill - or feed them to their dogs. They need FAT to survive! So they focus on eating the fatty parts, including bone marrow.

So, in some cultures, while the men are out hunting, the women spend time making bone grease. This takes a lot of work. They take bones and break them into small pieces with a stone hammer. They boil them for several hours. The fat floats to the top. Then they let the water cool and skim off the fat.

There's been evidence for people doing this as far back as 28,000 BC. But now some scientists have found a Neanderthal 'bone grease factory' that's 125,000 years old!

This was during the last interglacial, in Germany. In a site near a lake, called Neumark-Nord, Neanderthals killed a lot of bison, horses and deer and crushed their bones, leaving behind tens of thousands of small bone fragments.

• Lutz Kindler et al, Large-scale processing of within-bone nutrients by Neanderthals, 125,000 years ago, https://www.science.org/doi/10.1126/sciadv.adv1257

Thanks to @sarahtaber for spotting this!