Conservationists in Mexico City reported on Thursday (February 9) that there has been a decrease in the number of monarch butterflies migrating to their protected reserve in Mexico.
The study was carried out by the World Wildlife Fund together with U.S. and Mexican environment groups, CONANP and SEMARNAT in 2016-2017.
It showed that during the second half of December 2016, 13 colonies of the plucky orange and black creatures were recorded, with seven in Michoacan and six in the State of Mexico, occupying 2.91 hectares of forest. Eight colonies (2.22 hectares) were located within the protected reserve and five colonies (0.69 hectares) located outside.
These figures represent a decrease of 27.43 percent with regards to the occupied area (4.01 hectares) during the 2015-2016 season.
“There was a decrease of 27 percent but (numbers) were diminished mainly due to the extreme weather events that we had last season, where there was heavy snowfall, where there were cold fronts, with very low temperatures. It is an insect that although it resists a lot, temperatures of minus four degrees centigrade, without a doubt – last season there was a death of about six million of these butterflies,” said Alejandro del Mazo, Mexico’s National Commissioner for Protected Natural Areas, Alejandro Del Mazo.
According to reports, the overall number of the majestic orange and black butterflies that travel thousands of kilometres (miles) on a migration into the United States and Canada is still well below a high in the 1 billion range two decades ago.
“The phenomenon, as a phenomenon, is in danger. It is in danger of extinction. It is in danger of disappearing due to these three factors that I mentioned, loss of habitat in the United States, deforestation in Mexico and these climatic events. As a species, no, because there are butterflies in many parts of the world, there are butterflies that arrive to Europe, that have been able to migrate to those areas but that do not achieve a migration like the monarch butterfly in North America,” said Omar Vidal, director general of the World Wildlife Fund in Mexico.
The study looked at areas where the butterflies congregate when they spend the winter in Mexico’s Oyamel forest. They have suffered mightily over the years from the expansion of farmland, sprawling housing developments and the clear-cutting of natural landscapes along their migration path, experts say.
Monarchs lay eggs only on milkweed plants, which grow wild throughout the United States. But the milkweed, on which their larvae feed, can cause stomach problems for cattle that eat it, so ranchers and farmers destroy it.
The butterflies breed in Mexico and then have three more generations as they travel north to Canada.
Millions of butterflies fly en masse, often alighting on the same trees their grandparents used.
While an estimated 1 billion monarchs migrated in 1996, only about 35 million made the trip in 2013, according to conservationists tracking butterfly numbers.
REUTERS
