The Soviet Union launched its first man-made satellite in 1957, and the United States subsequently launched its spy satellite program, codenamed Corona, to find the location of the Soviet missile launch. But U.S. spy satellites have inadvertently captured something else. Scientists used satellite photos taken during the Cold War to track changes in the number of species in areas with little historical history.
The researchers tested this method in bobak marmot, a grassland that lives in Kazakhstan’s grasslands. The Soviet Union converted millions of hectares of grassland into farmland in the 1960s. Using black-and-white satellite photos, the researchers identified more than 5,000 dry-breeding settlements, compared with modern digital images from the local area, and mapped more than 12,000 arid caves. The researchers found that the number of otter caves has fallen by 14% since the 1960s and by as much as 60% in places converted into farmland. The study was published in the journal Proceedings of the Royal Society B.