On an average morning, Susan Glass can sit on the patio at her condominium complex in Saratoga, California, and identify as many as 15 different bird species by ear: a Steller’s jay, an acorn woodpecker, an oak titmouse. For her, birding is more than a hobby. “Birds are my eyesight,” said Glass, a poet and an English professor at West Valley Community College who has been blind since birth. “When I check into a hotel in Pittsburgh, I might remember the rock dove and the house finch in the parkin