Mr. St. It is the general nature of them to associate together, and build in numbers on the same or adjoining trees. But this is often in the midst of woods or natural groves. However, they have no objections to the neighbourhood of man, but readily take to a plantation of tall trees, though it be close to a house; and this is commonly called a rookery. They will even fix their habitations on trees in the midst of towns; and I have seen a rookery in a churchyard in one of the closest parts of London.
Fr. I think a rookery is a sort of town itself.
Mr. St. It is: a village in the air, peopled with numerous inhabitants; and nothing can be more amusing than to view them all in motion, flying to and fro, and busied in their several occupations. The spring is their busiest time. Early in the year they begin to repair their nests or build new ones.
Fr. Do they all work together or every one for itself?
Mr. St. Each pair, after they have coupled, build their own nest; and instead of helping, they are very apt to steal the materials from one another. If both birds go out at once in search of sticks, they often find at their return, the work all destroyed, and the materials carried off; so that one of them generally stays at home to keep watch. However, I have met with a story which shows that they are not without some sense of the criminality of thieving. There was in a rookery a lazy pair of rooks, who never went out to get sticks for themselves, but made a practice of watching when their neighbours were abroad, and helped themselves from their nests. They had served most of the community in this manner and by these means had just finished their own nest; when all the other rooks in a rage, fell upon them at once, pulled their nest in pieces, beat them soundly, and drove them from their society.
Fr. That was very right—I should have liked to have seen it. But why do they live together if they do not help one another?
Mr. St. They probably receive pleasure from the company of their own kind, as men and various other creatures do. Then, though they do not assist one another in building, they are mutually serviceable in many ways. If a large bird of prey hovers about a rookery for the purpose of carrying off any of the young ones, they all unite to drive him away. When they are feeding in a flock, several are placed as sentinels upon the trees all round, who give the alarm if any danger approaches. They often go a long way from home to feed; but every evening the whole flock returns, making a loud cawing as they fly, as if to direct and call in the stragglers. The older rooks take the lead: you may distinguish them by the whiteness of their bills, occasioned by their frequent digging in the ground, by which the black feathers at the root of the bill are worn off.
Fr. Do rooks always keep to the same trees?
Mr. St. Yes; they are much attached to them, and when the trees happen to be cut down, they seem greatly distressed, and keep hovering about them as they are falling, and will scarcely desert them when they lie on the ground.
Fr. Poor things! I suppose they feel as we should if our town was burnt down or overthrown by an earthquake.