How does Cosimo survive the winter in The Baron in the Trees?

Throughout the year, Cosimo had been hunting for food; he had saved the animals’ skins. As winter approached, he sewed the skins together into a fur jacket; he also made goatskin trousers. He wore a hat made of wildcat skin and slippers, perhaps of badger skin. Cosimo made and slept in a sleeping bag, also of goatskin with the fur turned inside. He hung it from a tree branch and slept suspended in it with his gun and powder flask.
To stay warm and cook, Cosimo rigged up a hearth on the ground, above which a spit was suspended. He made a fire and roasted game from the trees with long tools. He also had water, diverted from a nearby stream by tubes running through a large oak tree’s branches. Cosimo also kept a she-goat and a hen, for milk and eggs, respectively. For the rest of the food that he could not hunt or gather, he traded with the village peasants.
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