LONDON - Rooks, a member of the crow family, are surprisingly innovative when it comes to searching food - they are not only capable of using tools but also making and modifying them for their use.

“This finding is remarkable because rooks do not appear to use tools in the wild, yet they rival habitual tools users such as chimpanzees and New Caledonian crows when tested in captivity,” said Chris Bird of Cambridge University, co-author of the study.

In a series of experiments, the rooks quickly learnt to drop a stone to collapse a platform and acquire a piece of food, and subsequently showed the ability to choose the right size and shape of stone without any training.

Not only could they use stones to solve the task, but they were flexible in their tool choice, using and modifying sticks to achieve the same goal.

When the correct tool was out of reach, they used another tool to get it, demonstrating the ability to use tools sequentially.

In further tests, the rooks were able to use a hook tool to get food out of a different tube and even creatively bent a straight piece of wire to make the hook to reach the food, said a Cambridge University release.

“This is the first unambiguous evidence of animal insight because the rooks made a hook tool on their first trial and we know that they had no previous experience of making hook tools from wire because the birds were all hand-raised,” said Nathan Emery, Queen Mary University and Bird’s supervisor, in whose lab these experiments were performed.

These results were published online in the Proceedings of the National Academy of Sciences.