UPSC Prelims 2023 Q19: Tool-Making by Animals — Explained
Which one of the following makes a tool with a stick to scrape insects from a hole in a tree or a log of wood?
- Fishing cat
- Orangutan
- Otter
- Sloth bear
Answer: (b) Orangutan
Statement-wise explanation
- a: incorrect — The fishing cat (Prionailurus viverrinus) is a wetland cat of South and South-East Asia. It catches fish by scooping them out of the water with its paws, helped by semi-retractile claws. It is not known to make or use tools. It is listed as Vulnerable on the IUCN Red List.
- b: correct — Orangutans pick a stick of the right size and strip it bare. They then use it to pull insects or honey out of tree holes, or to pry seeds from hard-shelled fruit such as Neesia. Changing a stick to fit a task counts as tool-making, not just tool use. This behaviour is best known from orangutans in Sumatra.
- c: incorrect — The sea otter does use tools, which makes this a trap option. It floats on its back and breaks open clams, snails and crabs against a stone balanced on its chest. It uses a stone it finds, though, not a stick it shapes, and it feeds on shellfish rather than insects from trees. India's otter species are not known for tool use.
- d: incorrect — The sloth bear (Melursus ursinus) does eat insects, which makes this a trap option too. It does not use tools. It rips termite nests open with its long claws, closes its nostrils, and sucks up the termites through its funnel-like lips and a gap in its front teeth. It is listed as Vulnerable on the IUCN Red List.
How to eliminate
Only knowing the fact fully settles this, but basic knowledge narrows it fast. The question describes changing a stick and using it to probe a hole. That needs grasping hands and good problem-solving, which points to a primate. Of the four options only the orangutan is a primate, and it is a great ape. The other three are carnivores that hunt with their paws, claws or mouth. Two options are traps. The sloth bear eats insects, but it gets them with claws and suction. The sea otter uses tools, but it uses stones on shellfish, not sticks on insects. Remember: great apes (chimpanzees and orangutans) make stick tools to get insects; sea otters use stones; sloth bears use suction.
Know more
Tool use vs tool-making
An animal uses a tool when it handles an outside object to reach a goal, such as a stone used to crack a shell. It makes a tool when it first changes that object to suit the job, such as stripping the leaves off a twig. Tool-making is rarer and points to planning. It was once thought to be found only in humans. Then, in 1960, Jane Goodall saw chimpanzees at Gombe in Tanzania shaping grass stems and twigs to "fish" termites out of their mounds.
| Animal | What it does | Make or use? |
|---|---|---|
| Orangutan | Strips sticks to get insects or honey from tree holes and to pry seeds from fruit | Makes |
| Chimpanzee | Shapes twigs to fish termites; cracks nuts with stones | Makes and uses |
| New Caledonian crow | Shapes twigs and leaves into hooks to pull out grubs | Makes |
| Woodpecker finch (Galápagos) | Uses cactus spines or twigs to pry insects out of bark | Uses or changes |
| Sea otter | Breaks shellfish against a stone held on its chest | Uses |
| Sloth bear | Rips nests open with claws and sucks up termites | No tools |
| Fishing cat | Scoops fish out of water with its paws | No tools |
Orangutans in brief
- They are the only great apes of Asia, and they live in trees in the rainforests of Borneo and Sumatra.
- There are three species: Bornean (Pongo pygmaeus), Sumatran (P. abelii) and Tapanuli (P. tapanuliensis). The Tapanuli orangutan was described in 2017. It is the first new great ape species found since the 1920s, and fewer than 800 are left, all in the Batang Toru forest of North Sumatra.
- All three species are Critically Endangered on the IUCN Red List. The main threats are logging and clearing forest for oil-palm plantations.
UPSC often pairs a striking behaviour with one right animal and some that look plausible. Learn the specific method each animal uses, not just its diet.