The cold snap in the eastern U.S. could be deadly to birds, some of which are being driven farther south than normal in search of water and food, experts say. People aren't the only ones suffering in the cold gripping much of the nation, the American Bird Conservancy said in a release Tuesday. "Birds can survive the kind of severe weather we are seeing, but only if they get needed food and water," conservancy biologist Daniel Lebbin said. "Their ability to stay warm in frigid temperatures requires them to eat sufficient food." Putting out extra food on bird feeders and on the ground, including suet and fruit for birds that don't normally eat seeds, can make the difference between life and death for some birds, the conservancy said. An ice-free source of water is also vital, Lebbin said. "Water is just as important as food, if not more so. By providing warm water frequently, or installing a bird-bath heater, people can help the birds out substantially during severe weather events," he said. Weather events like this cold snap are not unusual, Lebbin added, and while they are not expected to significantly affect wild bird populations, taking steps to mitigate the expected mortality on birds is something his organization is routinely asked about when the weather goes bad. "People care about birds and other wildlife in this country. We get calls all the time from people wanting to know what they can do to protect our wildlife," he said. "Right now, there is a greater sense of urgency."