Birds are found to be clever tool makers

Birds may have a basic understanding of physics, recent research by Oxford zoologists suggests. In an article to be published in Science this week [Thursday], the researchers report the findings of an experiment in which New Caledonian crows bent wires to make hooks appropriate to retrieve food from a cylinder. This is the first time any animal has been found to show some understanding of cause and effect, and to make a new tool for a specific task.

The experiment built on a chance observation, when a captive female crow spontaneously bent a piece of wire and successfully used it to lift food from a vertical pipe. To examine such tool-making behaviour by crows more systematically, the researchers set up an experiment where a male and a female crow were presented with a straight piece of wire and a glass tube with some food located at the bottom. The birds needed some tool or implement to get the food out of the tube. The female crow bent the piece of wire and retrieved food successfully nine times out of ten.

The birds had used hooks before but never made any. While they were familiar with similar experiments they had no experience with wires. The findings may have wide-ranging implications regarding birds? understanding of physics and their quality of reasoning about cause and effect.

The team is now exploring whether New Caledonian crows are exceptionally clever in many other respects, or whether they have brains specially evolved for the use and manufacture of tools.

Alex Kacelnik, Professor of Behavioural Ecology, said: `Although many animals use tools, purposeful modification of objects to solve new problems, without training or prior experience, is virtually unknown. Experiments with primates, who are much closer relatives of humans than birds, have failed to show any deliberate, specific tool making and human-like understanding of basic physical laws.

`We are now keen to elucidate if New Caledonian crows are outstanding in all aspects of their intelligence or only in those related to tool manufacturing and use. In other words we want to understand what kind of mind these crows have. This will give us the opportunity to test hypotheses about the conditions which are needed for complex cognition to evolve.`