Ravens — not too ravenous to plan lunch

BEST-KNOWN as guardians of the Tower of London, new research shows that ravens are among the cleverest birds.

Scientists discovered that they can plan for their future food needs. During tests, the birds delayed immediate gratification if they knew there might be a larger prize in the future.

The ravens were given a choice between a small snack to eat immediately and a tool which they could use later to obtain something more nourishing. In 80 per cent of cases, they chose the tool.

The study, by cognitive zoologist Matthias Osvath, of Lund University in Sweden, proves that using long-term memory to plan for the future is not unique to humans.