We have been watching large flocks of rooks circling and weaving in a chimney formation over the heronry area, one morning, and then over the rookery on another early day.
These are birds moving out from their family groups into the safety of autumn flocks.Here they use all the eyes of the group to find food and have a community feed in.
They eat insects amongst many foods. Perhaps they are cleaning out the many wrigglers that have found a home in the nearby nests of the herons and rooks. Are they nature's cleaning service ?
One of our visitors said that a group of rooks is called a parliament and so if it was a mixed group, say, with jackdaws, it would be a coalition. :-))
It's teamwork in nature.