The number of monarch butterflies at their wintering areas in Mexico dropped by 59% this year to the second lowest level since record keeping began, experts said Wednesday, blaming heat, drought and loss of habitat.
The number of monarch butterflies at their wintering areas in Mexico dropped by 59% this year to the second lowest level since record keeping began, experts said Wednesday, blaming heat, drought and loss of habitat.
The butterflies’ migration from Canada and the United States to Mexico and back again is considered a marvel of nature. No single butterfly lives to complete the entire journey.
The annual butterfly count doesn’t calculate the individual number of butterflies, but rather the number of acres they cover when they clump together on tree branches in the mountain pine and fir forests west of Mexico City. Monarchs from east of the Rocky Mountains in the United States and Canada overwinter there.
Mexico’s Commission for National Protected Areas said the butterflies covered an area equivalent to 2.2 acres (0.9 hectares), down from 5.4 acres (2.21 hectares) last year.
The lowest level was in 2013 at 1.65 acres (0.67 hectares).
Experts said heat and drought appeared to be the main culprits in this year’s drought.
“It has a lot to do with climate change,” said Gloria Tavera, the commission’s conservation director.
