Delicate and beautiful, Monarch butterflies are one of North America’s most beloved natural treasures. And perhaps nothing is more breathtaking than witnessing hundreds of the gently fluttering creatures in migration along their 3,000-mile route from Mexico, where they spend the winter, before heading back to Canada every spring.
These winged wonders are the only known insect to embark on this type of annual round-trip migration, and it truly is a group effort: It can take three to four generations for the insects to make just the northern migratory leg of the journey.
But over the last 20 years, the Monarch population has been in decline. Some estimates show as much as a 90% drop in their numbers, due in large part to a variety of inter-related factors including loss of habitat, weather, deforestation and the use of herbicides. Also impacted is the Monarch’s key plant for survival—the milkweed—especially throughout the butterflies’ “nectar corridors.”
What are nectar corridors?
Nectar corridors are the migratory routes that pollinators such as the Monarch follow every year. These routes help the butterflies, bees and other insects to take advantage of the plants coming into bloom during their progression from south to north in the spring and back again in the fall. Much of the milkweed that Monarchs rely on has typically been found within these pathways.
Inside these nectar corridors, milkweed species formerly grew in abundance alongside farm crops, providing fertile feeding and breeding grounds for the Monarchs. But recently, a combination of factors has begun killing off the milkweed, thereby narrowing the Monarchs’ nectar corridors. In the Midwest alone, more than 120 million acres of farmland formerly abundant in milkweed has been lost to the Monarchs.
Why do Monarchs need milkweed?
Monarch feeding on Milkweed
While butterflies can feed on the nectar of many different flowering plants, Monarchs rely specifically on milkweed for laying their eggs. Milkweed produces a poisonous latex substance that Monarchs are impervious to, but which makes Monarchs unpalatable to predators. As Dr. Art Shapiro, UC Davis professor and author, explains, “The Monarch butterfly uses the milkweed plant to lay eggs, which the caterpillar consumes, providing both a food source and a protection from birds, as the milkweed makes the caterpillar and butterfly poisonous if consumed.”
What can be done to increase the number of milkweed plants?
The good news is that steps are being taken to bring North American nectar corridors back to life for the Monarch. For example, last year the Transportation Department and U.S. Fish and Wildlife Service announced plans to help rehabilitate butterfly habitats along Interstate 35—a federal U.S. highway stretching from Duluth, Minnesota, to the Texas–Mexico border. The goal is to rehabilitate prairie vegetation, educate target audiences, and provide seasonal breeding habitats along the flyway—and to increase the Monarch population from 56.5 million to 225 million by 2020.
Norwex Movement members can help the Monarch, too. No matter where you live, there is sure to be a variety of milkweed that will do well in your garden. Consider planting milkweed in your garden, backyard or community garden to help provide feeding and breeding “stepping stones” for the Monarchs along their semiannual migration paths.
For those in colder climates looking for a DIY project, here’s a series of tips from MonarchButterflyGarden.net that will help you sow your own milkweed seeds in time for the spring migrating season.
The Washington Post: Are monarch butterflies really being massacred?
Green Blog: Monarch Butterflies Considered for Endangered Species List
The Washington Post: The monarch massacre – Nearly a billion butterflies have vanished
Science: Monarch butterfly studies tell a perplexing tale
Desert Museum: Migratory Pollinators Program
Monarch Joint Venture: Milkweed for Monarchs [PDF]
Auburn Journal: Monarch butterfly considered for endangerment status
Government Executive: Obama Is Creating a 1,500-Mile ‘Butterfly Corridor’ to Help Monarchs
National Strategy to Promote the Health of Honey Bees and Other Pollinators [PDF]
Monarch Butterfly Garden: Winter Sowing Milkweed Seeds Part 1: Supply Checklist
Savvy Gardening: Plant milkweed to help save the monarch butterflies