Population status of American cranes

American cranes were once widely distributed in the North American continent, and there were traces of their activities from grasslands to permafrost. However, with the influx of European immigrants into North America, a large number of hunting, egg collection and habitat destruction have gradually disappeared from their breeding grounds-many grassland swamps in the United States and north-central Canada. After 19, the living environment of American cranes went from bad to worse. The water in the wetland has been drained and turned into agricultural land and cities where people live. Hunting American cranes often happens. By 194 1 year, only 16 American cranes survived the winter and became the most endangered cranes in the world.

In recent 100 years, American cranes are on the verge of extinction due to hunting, egg collection and habitat destruction. American cranes were found in the Gulf of Mexico, Texas, where they spent the winter, and six of them later died in a hurricane. 1937, the American government bought the land and established the Arkansas wildlife sanctuary. Later, the nesting site of this crane was discovered in northwest Canada.

1966, the national wildlife management agencies of the United States and Canada decided to take 1 from the eggs of American crane nests to create a captive crane colony. This does not affect the growth rate of wild cranes. This practice has been repeated for many years and 60 crane eggs have been collected. There are about 25 American cranes in captivity in Patac Forest, Maryland, USA. Millions of dollars have been spent on the protection and research of American cranes, and the number is increasing.

In 1982, the number of wild American cranes increased to 90, and the total number reached 127 when 37 cranes were artificially raised. American cranes are the rarest and most endangered cranes in the world. In order to save American cranes, scientists hatched them by artificial incubation, then disguised them as American cranes with ultralight planes and remote-controlled robots, and took these artificially raised small American cranes to the wildlife sanctuary in southern Florida for the winter.