List of Headings
- i The theory linking intelligence in birds and survival
- ii The influence of humans on tool use
- iii The theory linking cognitive ability and living in a society
- iv Reviewing long-held beliefs
- v Intelligence helps birds to remember
- vi How some birds trick each other
- vii Physiological evidence of birds' intelligence
- viii Several examples of birds' use of tools
- ix One species' multiple tool-using techniques
Questions 1-7
Drag a heading into each box.
1. For centuries, many scholars maintained that humans were the only intelligent organism on Earth. However, exciting new research on a number of animals, particularly birds, has called into question the uniqueness of humans, forcing us to reconsider this opinion.
2. When white-winged choughs come across shellfish they have been known to use rocks as hammers to crack open the recalcitrant shells. Black kites have been reported dropping bait into lakes to bring fish to the surface of the water, thereby making them easier to catch.
3. Other species, such as birds of prey, live in a more challenging environment, where food may be distributed erratically, hidden from view or highly mobile. Then only the smartest in each generation will live and reproduce.
4. New Caledonian crows boast many different tools in their tool kit. They use a hooked tool made by removing all but one of the side branches from a twig. They fashion serrated rakes (using their beaks as scissors) from stiff, leathery pandanus leaves. They also make probes by modifying their own moulted feathers.
5. The team uncovered a clear relationship: birds with relatively large forebrains are able to invent fresh solutions to ecological challenges, and to exploit the discoveries and inventions of others, more often than birds with relatively small forebrains.
6. Intelligence in birds may also arise as a result of selection to overcome the dynamic challenges of communal living. Since this involves competition between group members, to be successful, a social animal may need to be able to reflect on its own intentions, as well as those of others.
7. Perhaps the best example of deception among birds comes from the white-winged choughs. A chough that has been sitting totally still on the nest while the rest of the group is foraging out of sight will comically spring up and frantically start to preen the chicks as soon as some of its group members come into view. It is likely that these young choughs are only motivated to help when others are watching because they are concerned about their social status.