The population of butterflies is calculated by the area they cover when gathered on tree branches. The monarch population fell from 2.8 hectares down to 2.2 hectares in one year. They once covered more than 18 hectares.
Some conservationists think that loss of habitat in Mexico is leading many of these eastern monarch butterflies, which reside in the northeast United States and southern Canada, to winter instead along the West Coast of the United States. More than 330,000 butterflies were tallied in California and Arizona this year, the highest number in the last six years.
Droughts, frost and “extreme temperatures” across the United States are killing the monarchs’ food source — milkweeds — and causing their habitats to dwindle, the director of Mexico’s nature reserves, Humberto Peña, said at a news conference last week. In 1998, the residents of the Crescencio Morales farming community set fire to monarch butterfly habitats to make space to log the land, village leader Erasmo Álvarez Castillo told the Associated Press.Article content
Monarch butterflies fly at the Sierra Chincua butterfly sanctuary in Michoacan, Mexico, last December.Homero Gómez González was a former logger who became a conservationist and was one of central Mexico’s most prominent defenders of the monarch butterfly. In an interview within December 2019, he said he began working with scientists and conservationists from the WWF to put Michoacán’s Rosario sanctuary on the map and bring in tourism.
Who counts them