There are few things as astounding and inspiring as the sight of thousands of butterflies roosting so thickly together that the trees seem to have fur, or soaring through the sky by the hundreds in a balletic cascade. We are blessed in North and Central America to be treated to the migration of the monarch butterflies twice each year. For many, the fluttering of majestic, orange-patterned wings is the truest harbinger of Spring, as these enchanting creatures make their way to warmer climes. If you’ve never had the pleasure of witnessing this phenomenon, I suggest this short video from PBS: https://www.youtube.com/watch?v=lWOySU_hAz0
Monarch butterflies, you see, are cold-blooded. They cannot survive a long, cold winter, so they have evolved to follow the warmth with the changing of the seasons. They are the only butterflies in the world to make a two-way migration, like that of birds, but that’s not the only remarkable thing about their journey: it is also the longest migration of any butterfly, ranging 2,000 miles (3,218 kilometers) or more each spring and fall. The Western monarchs (those to the West of the Rocky Mountains) spend their summers in the Northern U.S. and Southern Canada. When the days start to shorten and cool, they head South to overwinter along the coast of California. The Eastern monarchs summer in the Northern U.S. and Southern Canada on their side of the Divide, then move South to the mountain forests of Mexico, or East to sunny Florida for their winter homes.
We’ll take out just a moment to mention there is a species of monarch butterflies native to Florida that remain active year-round, rather than hibernating, and do not seem bound to any large migration, though they do shift somewhat with the seasons.
The lifespan of a monarch butterfly is around 40 days, except for those that hibernate, which can live up to nine months. This means that it’s not the same butterflies that roost for the winter, huddled together to conserve body heat, that return the next fall: its’ their great-great-grandchildren! Three generations may have come and gone on the trek Northward and back, but the butterflies still find their way to the same winter roosts, even to the very same trees. Scientists are still studying this seeming generational memory, or instinct, but no one yet understands exactly how it works.
We do know that the butterflies that emerge in Spring and Summer are different from fall emergent butterflies. The warm weather flyers seek food and mates, and lay eggs, but their children born to cooling weather seem to know a long trek is ahead: they spend their time stockpiling energy, focused on getting enough nectar to fuel them while they make their long flight, as well as to sustain them during the months-long winter rest. They won’t mate until warmed by Spring.
But the eternal cycle of these seasonal harbingers is under dire threat. Population counts at monarch butterfly wintering sites in Mexico showed a decrease of 26% this year, and the Western Monarch Thanksgiving Count, which carefully surveys groves of trees along the California and Northern Baja Coast recorded only a sobering 1,914 butterflies total out of 246 sites surveyed. In 1997, when the Thanksgiving Count began, over a million butterflies were corded but fewer than 100 sites were surveyed. The reduction in numbers is attributed to climate change, loss of habitat, and exposure to pesticides and toxins. The Mexican forests that the monarchs depend on for roosting are reportedly being degraded by illegal logging, wind and drought, as well as some sanctioned logging. Here in the U.S., habitats that provide the safety of cover from predators, food, and the milkweed essential for monarch caterpillars are being increasingly plowed under or treated with harmful agents.
Although the extinction threshold for the Western Monarch was predicted at a population of 30,000, and despite being submitted for inclusion under the U.S. Endangered Species Act, on December 15, 2020, the U.S. Fish and Wildlife Service announced that listing the monarch butterfly under the Endangered Species Act was “warranted but precluded by higher priority actions.” This means that the endangerment of the monarch butterfly is recognized, but other endangered species are being considered higher on the priority list, therefore monarchs have not been granted full protection under the law. They have, however, been deemed a “candidate” species, so they will be considered more often in project planning and review on lands managed by federal agencies, and there will be greater incentives for voluntary actions by the private sector. The ruling also may open opportunities for conservation funding.
There is hope, and you can help! If we all come together to provide havens for the migrating monarchs, we can turn the tide. Monarch butterflies require nectar plants, host plants for laying eggs and nourishing caterpillars, and plants for hiding and nighttime roosting. You don’t have to have acres of land: even balcony-bound container gardens can save a butterfly. Here are come guidelines to get you started:
- Plant milkweed: Monarch butterflies lay their eggs exclusively on varieties of milkweed, which is referred to as their “host” plant. Ingesting the leaves makes the caterpillars toxic to birds. Milkweed
- Plant native species: Choose plant varieties native to your area, as these are what your local butterflies will be familiar with and searching for. These plants have also evolved with the conditions of your region, and are most likely to thrive.
- Plant for season-long blooms: Different plants flower at different intervals. With just a little planning, you can ensure that your garden offers nectar all through Spring to Autumn.
- Plant pesticide-free: Butterflies are insects, so insecticides are a problem, as are other toxic chemicals. Even natural products can be harmful to butterflies. Luckily, it’s easy to educate yourself on pest control that won’t harm your desired visitors.
- Get active: Monarch conservation organizations can be found across the continent. Add your voice to the call for recognition of the vital role pollinators play in our ecosystem.
We really can make a difference for these beautiful bringers of joy. Come to our plant nursery to find out how to make the biggest difference in your region.