We are investigating whether the crows’ unusual tool-using abilities are reflected in their brain structure.
Bigger animals have bigger brains. To relate brain size to intelligence, it is possible to compare actual brain size with expected brain size for related animals, given their body weight. For example, parrots and crows have big brains when compared to other birds of similar body weight.
However, brain size on its own is a very crude indicator. Looking inside the crows’ brains might help to identify specializations related to their extraordinary tool-oriented behaviour.
Many techniques are available to highlight structures within the brain. Nissl staining shows gross tissue morphology, and immunohistochemistry reveals the chemicals contained within individual neurones. In an ongoing research project, we compare the detailed neuroanatomy of New Caledonian crow brains with those of other corvids to try to identify possible tool-related adaptations. Dr Radha Nair-Roberts is collaborating on this research