I think “widowmakers” doesn't refer to spiders, but things to watch out for, like falling trees, slippery ledges, sharp rocks, and so on. They're one of the “f

I think “widowmakers” doesn't refer to spiders, but things to watch out for, like falling trees, slippery ledges, sharp rocks, and so on. They're one of the “five Ws”—a mnemonic list of things you need (or need to keep away from) to survive in the wilderness: water, weather, wigglies (which would include spiders), widowmakers, and wood.