These lands are federal property with no towns and no agricultural development. Introduced plants also pose threats to the tortoise. They compete with the tortoise's preferred native plants, and, because many exotic grasses are extremely flammable, they have brought fire into the desert where it was previously rare. Poaching is a very big problem, particularly among certain cultural groups which believe tortoises have strong aphrodisiac and medicinal properties. Although thousands of desert tortoises still remain, trends show that some populations have declined by 90 percent since the 1980s.
Some individual populations are stable, but they are ever fewer.
Cities and towns have encroached upon the desert, making desert life easier for ravens. Ravens no longer need to rely solely on the desert for food and water. They nourish themselves at garbage dumps, landfills, and sewage ponds. Although ravens have probably always preyed on vulnerable, young tortoises, there were historically very few ravens in the desert. Now they have now become a major predator of juvenile tortoises.