"A flock of a dozen s spends the year in my woods. In winter, when we are harvesting diseased or dead trees for our fuel wood, the ring of the axe is dinner gong fro the chickadee tribe. ... But for diseases and insect pests, there would likely be no food in the trees, and hence no chickadees to add cheer to my woods in winter. Many other kinds of wildlife depend on tree diseases. My s chisel living plants, to extract fat grubs from the diseased heartwood. My s find surcease from s and s in the hollow heart of an old ; but for this diseased tree their sundown serenade would probably be silenced. My s nest in hollow trees; every June brings its broad of downy ducklings to my woodland slough. All squirrels depend, for permanent dens, on a delicately balanced equilibrium between a rotting cavity and the scar tissue with which the tree attempts to close the wound. The squirrels referee the contest by gnawing out the scar tissue when it begins unduly to shrink the amplitude of their front door."