So what conclusions can be drawn from the research?
Evidence is building up from experiments such as these that the birds are able to plan their actions in advance, which is very interesting for understanding their cognition. They don't seem to be responding in a pre-programmed sort of way. It may even be possible that they're able to view a problem and work out what the answer is. However, a major difficulty is assessing whether this tool-using behavior is a sign of intelligence. To some extent, this is related to the ecological circumstances in which the animal is found. So scientists want to find out much more about how the crows behave in their native habitat, and a team from Exeter and Oxford universities is carrying out research in New Caledonia. They're looking into whether the birds' way of searching for food gives them any possible evolutionary advantage.