Think your car gets good mileage? Blackpoll warblers, birds that weigh about one ounce, achieve the equivalent of 720 thousand miles per gallon each year when they migrate to warmer weather. We learn these facts and more with Chris Eberly, director of the Maryland Bird Conservation Partnership. Later this month he’ll be presenting, through the Natural History Society of Maryland: ‘Unlocking the Mysteries and Marvels of Bird Migration.”