Owl teenagers make the author’s acquaintance from their perch on a tree branch. (Karen Telleen-Lawton photo) Since the spring I have been entranced by two fledgling great horned owls in our backyard. I first spied them out of the nest about a month and a half ago, crying feeble squeals that seemed to beg their parents for rescue or food. Now they stare me down in the evenings with piercing yellow eyes. Usually, they peer at me from high in an oa…