{"fact":"New Caledonian crows can learn to make tools of a specific size by observing a template, even when rewards are random and the template is absent during manufacturing.","context":"Using a novel manufacture paradigm, crows were first trained to drop paper into a vending machine to retrieve rewards. They later learnt that only items of a particular size (large or small templates) were rewarded. At test, despite being rewarded at random, and with no physical templates present, crows manufactured items that were more similar in size to previously rewarded, than unrewarded, templates.","source":"S. Jelbert; S. Jelbert; R. Hosking; Adrian H. Taylor; R. Gray; R. Gray; R. Gray, Mental template matching is a potential cultural transmission mechanism for New Caledonian crow tool manufacturing traditions, 10.1038/s41598-018-27405-1","index":184}