March 14, 2020
See the full article:
https://www.cals.iastate.edu/news/releases/monarch-conservation-efforts-continu…
AMES, Iowa — The World Wildlife Fund and the Comisión Nacional de Áreas Naturales Protegidas (CONANP) released its 2019-2020 overwintering monarch population report. Adult monarch butterflies covered approximately seven acres of forest canopy in Mexico, less than half the area of last year’s population. Scientists estimate a long-term average of 15 acres of occupied forest canopy is needed to sustain the eastern North America monarch population.