Rooks are the most conservative birds, and sometimes nothing will induce them to form a colony where their presence and their cawing would be the perfecting touches to the trees of some ancestral park. The most hopeful plan to tempt them is to put up old empty nests or brooms, or to put rooks' eggs into a nest that happens to be the desired place for the colony. Their strong preference for certain sites is curious; they will crowd nest-trees on one side of a road, and yet pay no attention to other trees of the same sort, seemingly more perfect for their needs, and only a few yards distant. We have watched a case where for twenty years the rooks remained faithful to the original nest-trees of the colony. About ten years ago half these trees were cut down, and even then the evicted rooks would not build in trees across the road, though their tops touched the tops of the favoured trees, which became more crowded with nests than ever. But two or three seasons ago their favourite nesting-tree, a beech with far-spread top, began to show signs of disease; and then, after a deal of wrangling, two or three pairs were permitted to nest in the trees near by, hitherto despised. In the next season there were nineteen nests in these trees, and in the next twenty-six. The old beech meantime grew more and more feeble, as the rooks perhaps discovered by some brittleness in the twigs at the top; and after one more year, though it bore foliage, but not so luxuriantly as usual, the tree gave shelter to only two nests. And now the long-despised trees are the home of almost the entire colony. * * * * * When Rooks Build In February, the rooks pay visits to their home-trees, wheeling and squawking round about, and demolishing old nests. On fine February evenings they linger after sunset before setting off to their winter roosting-place. A few, who have begun work on new nests, turn back to the trees undecided, then turn again after their companions. Not until the beginning of March do the rooks seriously set about their building, in mid-March deserting the great roosting-places of winter and mounting guard over their rough nests of sticks. * * * * * Ways of the Crows Rooks would seem to believe that while there is life there is hope. A dead rook displayed before other rooks for the first time attracts no particular attention beyond a casual inspection. But if a rook is wounded, and especially if it hops about with a broken wing, other rooks will swoop about it, and hover above with wonderful perseverance, squawking all the time excitedly, even in spite of a man with a gun. We have seen a hundred rooks perch on a fence to take stock of a relative caught in a trap set to pheasant eggs.