{"fact":"A crow's meal isn't just about the whelk itself.  Scientists calculate the \"net energy gain\" by subtracting the energy used to find, open, and eat the whelk from the energy the whelk provides.","context":"This energy should at least compensate for the energy required to find and open the whelk, otherwise there would be a net energy loss to the whole foraging process.","source":"Frans Blommaert; Ruud Janssen, Dennett, Darwin, and Skinner Crows, 10.1177/147470490500300113","index":392}