Many naturalists have found themselves asking an important and worrying question this year: where have all the monarch butterflies gone?
Monarchs are one of the more well-known butterfly species, with their vibrant orange and black coloration. Unlike most butterflies, they are a migratory species, spending their winters in Mexico’s Monarch Butterfly Biosphere Reserve and their summers in the U.S. and Canada. During their northward journey, monarchs mate and lay eggs on milkweed plants before dying. Their offspring then continue the journey to more northern locations where they also mate and lay eggs on milkweeds. No one knows for sure how the butterflies find their way without the memory of previous migrations.
Their annual migration makes monarchs vulnerable, as they rely on intact forest in Mexico for overwintering, as well as milkweed plants for reproduction and nectar sources for energy during the trip. Habitat destruction and degradation throughout North America has, unfortunately, decimated all of these vital habitats. Unusual weather patterns this year have also hit monarchs hard. Freezing temperatures and heavy rain caused large die-offs of monarchs in Mexico over the winter.
National Geographic produced a great video about monarch butterflies and the threats facing them. You can watch it here.
If you’re in North America, you can help monarchs in a number of ways. First, plant milkweed species that are native to your region, both at your work and home landscapes. Swamp milkweed, despite its name, is actually quite tolerant of a range of soil and moisture conditions, and is native to most of North America. Common milkweed and butterflyweed are two other common (and attractive!) species of milkweed that should be easy to obtain from native plant retailers.
Second, provide food sources for monarchs. In particular, planting colorful, native flowers will help to attract monarchs to where your milkweed plants are. The Pollinator Partnership has regional guides for choosing native plants that indicate which plants attract butterflies.
Third, work with groups like MonarchWatch to monitor monarch populations. The more we know about monarch migration and changes in their population, the better we can help halt or reverse population declines.