River Otter - Lontra canadensis - swimming in the mill pond at Lenhartsville. I had never seen one in the wild before. They have been a protected species in Pennsylvania for decades, but their numbers and range have been increasing as otters have moved north from Maryland and south from New York into Pennsylvania. An adult male otter may stake claim to a territory encompassing more than a dozen miles of streams, so one ought not to expect to see very many of them.