Manufacture and use of hook tools by New
Manufacture and use of hook tools by New Caledonian crows PAPER BY GAVIN R. HUNT
New Caledonian Crows are known for searching for their prey using twigs. Left, right: images showing pictures of crows using twig tools; circle indicates hook Center: drawings from Hunt (1996)
Two Types of Tools o Hooked-twig tool o Made from living secondary twigs o Stripped of leaves + bark o Hook present on wide ends o Stepped-cut tool o Made from Pandanus spp. Leaves o Can be either 2 - or 3 -stepped Right image: Pandanus spp. leaf Left image: 2 -stepped cut leaf tools Image showing hooked ends on hookedtwig tools
Evidence of Cognition? o Manufacture and use of standardized tools o Discrete tools: indicates different tools for different tasks?
Evidence of Cognition? o Manufacture and use of standardized tools o Tool shaping into hooks
Evidence of Cognition? o Manufacture and use of standardized tools o Associated behaviors:
Crow Tools vs. Human Tools o Qualities of crow tool use new to free-living non-humans: o High degree of standardization o Discrete tool types shaped into specific forms o Use of hooks o Early human tool use: o Lower Paleolithic = Early Stone Age o 2. 7 mil 200, 000 years ago
Video: “Tool-Making Crows Are Even Smarter Than We Thought – Nat Geo Wild” ◦ ~0: 40 1: 50 shows crow making hooked-twig tool ◦ https: //www. youtube. com/watch? v=UZM 9 Gp. LXep. U
- Slides: 8