So trouble began with the building, and for a week or so the warfare raged from box to box, the cock bluebird boldly defeating superior numbers again and again, only to have his gentle wife annoyed by other villains while he drove the first away, and his nesting material stolen in spite of him. Finally he resorted to what looked to me like well-planned and carefully executed strategy, though it may have been merely that fortune which favors the brave and persistent. The pair abandoned the box in the pear tree and started building in the one nailed against the side of the barn. The sparrows followed, of course. Then the bluebirds went back to the pear-tree box. The sparrows followed. The bluebirds then started building in the third box and daily brought material to each of the three, though ostensibly, I thought, to the second and third. At any rate the sparrows seemed to concentrate their attention more on these boxes. Meanwhile the bluebirds quietly completed the nest in the pear tree and later laid their eggs there, in comparative peace. The sparrows did not build in either of the other boxes. They did not want to. Neither did they care particularly about the material which they stole, for they did not continue to take it after the bluebirds had finished the pear-tree nest and were in a position to defend it. Their action was simply hoodlumism of the lowest and most despicable kind. [Illustration: The English sparrow has the true instincts of the browbeating coward] This was bad enough, yet it was merely petty annoyance compared to the deed without a name of which they were later to be guilty. The two young birds in the bluebird box were more than half grown. The blue was beginning to show in their wings along with the white of the conspicuous, growing quills, and the fuscous margin was already touching the breast feathers. The old birds, working with tremendous energy to feed these hearty youngsters, were both busy and often away from the nest together. At one such time the English sparrows descended upon this nest, entered, drove the young birds out to die upon the ground, unnoticed in the long grass, and started to take full possession. The bluebirds, returning too late, drove them away with more than usual despatch. This first called the affair to my attention. But I was too late.