Deforestation devastates already declining monarch butterfly populations

Each fall in late October, millions of monarchs head to southwestern Mexico City to hibernate in the high-elevation oyamel fir forests, where their return is culturally significant, viewed as the spirits of the deceased returning home for Dias de los Muertos. By February and March, the final generations of hibernating monarch butterflies come out of hibernation to find a mate. They then migrate north and east in order to lay their eggs on species of milkweed, which become generation one of the new year. When focusing on conservation of the monarch population, it is important that all stages of the monarch’s life-cycle are supported, this support is maintained throughout its migration. Monarch butterflies go through four stages during one life cycle (the egg, the larvae (caterpillar), pupa (chrysalis), and the adult) and through four generations in one year. The larvae hatch into baby caterpillars in 4 days, feeding on the nutrient rich layers of egg, and after two weeks of feeding on the milkweed, the larvae begin spinning their chrysalis and their 10-day process of metamorphosis, wherein they will emerge as an adult. Adults feed on nectar rich plants for 2-6 weeks and then die after laying eggs for generation two. The process continues through generations 2-3, until the fourth generation is hatched in September / October, which instead of dying after 2-6 weeks, migrates, hibernates, and begins the process again. The root issue of monarch decline can be sited to loss of suitable habitat, whether this is the physical space, or the loss of their sustenance: milkweed, and nectar plants. Forests in North America have experienced mass amounts of logging and deforestation which has jeopardized much of the biodiversity on the continent. The milkweed has been affected by the mass amounts of herbicides that are used to kill the competing plants of important crops in agricultural America as well as domestic use of RoundUp, a chemical compound used as weed killer. Monarchs perch on the trunks and branches of oyamel fir trees. Photo credit: Frans Lanting Mint Images from Sciance Magazine. There is work to be done at many levels to help correct this issue, and restore monarch populations. The most immediate and effective course of action would be a restructuring at the governmental level to prioritize the issues of climate change (and all its connotations), biodiversity loss, and the threatening of species. Regulating deforestation and managing pesticide use would reduce the habitat loss of the monarchs. Climate change is threatening the oyamel firs, the very species monarch butterflies rely on for overwintering, as is competition for land by agricultural use. Some Mexican scientists, including plan architect Cuauhtémoc Sáenz-Romero from the Universidad Michoacana de San Nicolás de Hidalgo, are undertaking the work of assisted migration, planting oyamel seedlings in elevations suitable for their growth beginning at 11,268 feet where the habitat is projected to be suitable by 2030, outside the current range and protection area of the Monarch Butterfly Biosphere Reserve.