How hard do you work for your dinner? Depends on how good the food is, right? The same goes for New Caledonian crows. These clever birds are famous for fashioning spears and hooks  out of twigs to reach beetle grubs holed up in rotting tree branches. But scientists didn't know why they went to so much trouble, when they could just use their beaks and talons to snag food elsewhere. It turns out tool use is a much more efficient way to hunt. Reporting  online today in Science¸ researchers have found that just a few wood-boring longhorn beetle grubs satisfy the crow's energy requirements for the entire day. Compared to hunting and foraging for smaller, less nutritious insects, nuts and seeds, tool-use makes for a smart meal plan.
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