Although believed to be naturally rare, the whooping crane has suffered major population declines due to habitat destruction and over-hunting. The population went from an estimated 10,000+ birds before the settling of Europeans on the continent to 1,300-1,400 birds by 1870 to 15 adults by 1938 in a single migratory flock. About thirteen additional birds lived in a non-migratory population in Louisiana, but this was scattered by a 1940 hurricane, which killed half of them, while the survivors never again reproduced in the wild.