Leaves on one large branch looked anemic one year, then small branches began to slough off. Local woodpeckers began to do their little feasting circle hops around a main trunk, and near the end the tree began to weep black streaks of sap.
This was my introduction to bacterial cankers in trees.
Since then, on walks with my dog I've started looking for signs of the canker in other trees throughout my neighborhood. Unfortunately, I've found it. These are photos of a neighbor's damaged live oak, proof that even our native trees are suffering.
This link from the Forest Service says that Hypoxylon Canker is not the cause of tree death. However, the fungus will infect the sapwood of trees that have been stressed …