Decline in the eastern migratory monarch butterfly population
Detailed Description
Decline in the eastern migratory monarch butterfly population as surveyed by the World Wildlife Fund-Mexico.
Populations in the high-elevation Oyamel fir forests where eastern monarchs overwinter are indexed by the area over which they occur.
Semmens et al. (2016) provided an adjusted measurement of population size which corrects for observation error.
Sources/Usage
Public Domain.