Pecan trees are large deciduous trees that grow between 65 to 170 feet tall. Before European settlement, pecans were widely consumed and traded by Native Americans. As a food source, pecans were a natural choice for a pre-agricultural society. Hollow tree trunks, found in abundance in pecan stands, offered a perfect storage location for the nuts. They can provide two to five times more calories per unit weight than wild game, and require no preparation.