Cold War spy satellite images reveal long-term declines of a philopatric keystone species in response to cropland expansion

Agricultural expansion drives biodiversity loss globally, but impact assessments are biased towards recent time periods. This can lead to a gross underestimation of species declines in response to habitat loss, especially when species declines are gradual and occur over long time periods. Using Cold War spy satellite images (Corona), we show that a grassland keystone species, the bobak marmot ( Marmota bobak ), continues to respond to...