Pausing to rest, the green heron in the above photo is performing an extremely important job for a bird, preening. Most birds have a preen gland, or uropygial gland, on their back, at the base of the tail just forward of where the tail feathers enter the body. You can’t see it unless you move the feathers aside, but its there. The gland contains an oily substance used to clean and coat the bird’s feathers. The bird reaches back with itsRead more