Data source: Brower, L.P. et al., Decline of monarch butterflies overwintering in Mexico: is the migratory phenomenon at risk?
Insect Conservation and Diversity (2012),
5, 95-100.
Last updated 2021/02/26.
Video
<><><> Fireflies <><><>
Are Fireflies Disappearing? Farmers' Almanac (2021/02/08)
<><><> North American Birds <><><>
Three billion North American birds have vanished since 1970 Science (2019/09/19)
<><><> Polar Bears <><><>
Are Polar Bears Endangered? Polar Bears International
<><><> Other Endangered Species <><><>
Endangered Species U.S. Fish & Wildlife Service
