Focus on birds
Hooded Crows (Corvus cornix) and Carrion Crows (Corvus corone)
The reason for considering these two species together is because that they are closely related and are able to hybridise. In general, within Britain, the Hooded Crow is found in the north and the Carrion Crow is found in the south. There is a geographical band between the north and the south which includes Rannoch where the two species interbreed. Most of the crows that you see in Rannoch are probably hybrids. Like other crows these two species are intelligent and despite persecution by man they continue to thrive. They are omnivores and are happy to eat carrion such as road kill.
The carrion crow is black but with the possibility of interference colours - reds, greens and blues. Hooded crows have grey over the back and upper wings.
Unlike rooks crows do not nest in colonies but they can be found in large flocks outside of the breeding season. The nest is an untidy bundle of sticks high in a tree.
If you see what looks like a crow at Rannoch you can be reasonably confident that it is a crow and not a Rook. Rooks are very numerous around Aberfeldy but do not seem to favour the habitat at Rannoch. The crows harsh call is different from the Rooks but it needs experience to distinguish between the two species. The Rook has a white bald patch at the base of the beak which is easy to see if you are reasonably close.
Crows are not very popular with farmers as they may attack injured or ill sheep.
The success of crows is down in large part to their intelligence. Crows living at the coast crows drop shellfish onto rocks to crack them open. In Japan crows drop nuts onto pedestrian crossings so that they will be cracked open by cars running over them and yet because the traffic stops for pedestrians the crows have time to feed before the cars start moving.