In the 1930s, sandhill cranes were generally extirpated east of the Mississippi River but their populations have recovered with there being an estimated 98,000 in the region in 2018, a substantial increase over the previous year. Although sandhill cranes are not considered threatened as a species, the three southernmost subspecies are quite rare. Resident populations, not migratory birds, cannot choose secure breeding habitat. Many subpopulations were destroyed by hunting or habitat change. Their desirability as a game bird brought them the nickname of "rib-eye of the sky" by a small group of modern hunters. The greater sandhill crane proper initially suffered most; by 1940, probably fewer than 1,000 birds remained. Populations have since increased greatly again. At nearly 100,000, they are still fewer than the lesser sandhill crane, which, at about 400,000 individuals continent-wide, is the most plentiful crane alive today.