Carrion crows (Corvus corone) are part of the corvidae family and are regarded as being highly intelligent. I have been observing their behaviour at the River Ythan nature reserve and recently documented them breaking the shells of mussels prior to extracting the meat to consume.
Similarly, to behaviour observed by thrushes they fly to a height with the mussel before dropping it onto a hard surface. In this case a concrete pier. They repeat the process until the mussel shell breaks. Whereupon they can hold onto the mussel with their feet and extract the meat using their bill.
Although common in many parts of the UK I find them challenging to photograph as they take are incredibly quick to fly if they register your presence. Presumably due to years of persecution and their innate intelligence.
Their ‘flighty’ behaviour coupled with their interesting behaviours are both fascinating and rewarding when you photograph them.