Learn how many are working to restore the playful river otter to Maryland. Bats in Pennsylvania have been found to holler echolocation screeches that seem to sound different than, say, Western Maryland bats, even though they're \saying\" the same thing. One scientist's conclusion: bats may speak in distinct dialects. The north branch of the Potomac River was brought to the brink of death by acidic poison pumped up from the bowels of drowned