Endangered migration of the Monarch butterfly
The forest surface occupied by these butterflies is used as an indirect indicator of the number of monarchs arriving to Mexico from Canada and the United States, after travelling over 4,000 km just to hibernate (November – March) in the temperate forests of Michoacán and Mexico. The monitoring identified 5 colonies within the Reserve (0.62 ha or 92.5% of the total surface) and 2 colonies outside (0.05 ha or 7.5%). The largest colony (0.52 ha, 77.6% of the total area) was found in El Rosario, Sierra el Campanario Sanctuary, Ocampo Municipality, and the smaller colony (0.01 ha) in the Carpinteros Indigenous Community, both located in Michoacán.
To carry out the monitoring, biweekly rounds were done throughout the 11 sanctuaries with historic presence of these butterfly colonies. This was useful to determine their location and the perimeter occupied, through the spatial analysis software. Furthermore, temperatures were also registered during November – December, which went from 4 to -2 °C and 4 to -3 °C, respectively. There were also intense colds: (1 to -3 °C) between November 28 and December 6, and (0 to -2 °C) between December 17 to 21, without extreme winter storms.
“Since 2003, alongside ejidos, communities and the government, the alliance WWF-Telcel supports the conservation and sustainable development of local forests, with aims to benefit monarch butterflies, local dwellers and tens of thousands of tourists who visit the sanctuaries each year,” highlighted Marcos Linares, Deputy Director of Telcel Corporate Marketing.
The main threats for the monarch butterfly within its distribution range in North America are the followings:
(i) Deforestation and forest degradation caused by illegal logging in hibernation areas in Mexico; (ii) reduction of its breeding habitat in Canada and United States caused by land use modifications and shortage of algodoncillo (plant used as food for larvae),