After de Soto's expedition through the Southeast, including Georgia, the Native American population decreased rapidly due to exposure to European diseases for which Native Americans had no immunity. One reason for this is that the Spaniards brought pigs with them from Spain (as a food source, and to trade), and the pigs carried viruses and bacteria for influenza, tuberculosis, and other diseases. Even after the Spaniards had passed by, escaped pigs transmitted those diseases to Native Americans and to the deer and turkeys that they hunted.