Every spring, the plants start blooming and pollen fills the air, turning everything an unpleasant shade of yellow. Meanwhile, we await the arrival of summer vegetables and the butterflies that are making the long trek northward.
A Cluster of Monarch Butterflies.
The Monarchs Current Dilemma
Although they might be mistaken for the Viceroy butterfly, which has a similar appearance, monarch butterflies (Danaus plexippus) are a familiar sight to many people living in North America. But they are now an endangered species.
Despite their reputation as beneficial pollinators and their presence as the state insect of many places, monarch butterflies on both sides of the United States are currently in serious state of decline. Their Mexican population has also decreased 80% over the past few decades.
These familiar creatures are suffering from various threats to their existence: habitat loss, widespread pesticide and herbicide use, lack of available food plants, and increasingly volatile weather patterns. Cars may pose significant risks to these creatures in some locations as well.
A Migratory Species
Most monarchs spend their winters in warmer environs and then fly north for the summer. Their ideal hangouts have good roosting spots, fresh water, ample sunlight, and limited predators.
As a result, the Eastern band (on that side of the Rockies) of monarchs usually heads for Florida in the winter. Or they wing it over to the Mariposa Monarca Biosphere Reserve in Mexico. The Western band (on the other side of the Rockies) usually flies toward southern California. Some monarchs even spend their winters along the Gulf Coast.
Although there is no genetic difference between the two bands of monarch butterflies that live in the United States, they’re often mentioned separately as distinct populations by scientists. There is also a nonmigratory subspecies that is native to Florida, Georgia, and several places further south.
The Monarch Life
Like many insects, monarch butterflies start life as an egg. Once they hatch, they enter the caterpillar stage (see photo below) where they gorge themselves on milkweed. After eating their fill, the future monarchs spend some time chilling in a blue-green shell with yellow spots. They eventually emerge as an adult butterfly with a pair of wings that measure 3.5 to 4 inches long and that are capable of moving them at speeds of up to 6 miles per hour.
The entire process can take as little as 25 days or as long as 7 weeks, depending on weather conditions. Low temperatures and damp weather during this time limit the monarch butterfly’s ability to reproduce. Only about 10% of the eggs laid in a given year survive to become adults and their lives are generally short. Adult butterflies live an average of 3 weeks, except for the last group born in a given year. Those individuals can live up to 9 months.
A Monarch Caterpillar.
Nom, nom, nom…
As caterpillars, monarchs are picky eaters. They are almost entirely dependent on various milkweed species as host plants. However, they will also eat white twinevine (Funastrum clausum), which is native to Florida, Texas, and other spots further south. Tropical monarch species in other portions of the world likewise enjoy the crown flower (Calotropis gigantea).
Adult butterflies will happily drink the nectar of other plants as well. Their preferred diet includes Indian hemp, asters, thistles, wild carrots, teasel, coneflowers, horseweed, spotted Joe Pye weed, common boneset, dame’s rocket, blazing stars (Liatris species), alfalfa, goldenrod, lilacs, red clover, and tall ironweed.
Butterflies can also obtain much needed nutrients from wet gravel or mud puddles. However, this behavior can be problematic if they’re drinking chemicals along with their water or if they are slurping up completely toxic substances like spilled oil.
The monarchs on the West Coast have been suffering from shockingly low numbers for quite some time. But they have been recovering, or at least stabilizing, since 2014. However, there is a significant possibility (11-57%) that both the Eastern and Midwestern monarchs may go extinct in the next 20 years.
Cool, damp weather during the winter months doesn’t produce many new butterflies. And changes in the weather patterns may also encourage the butterflies to migrate as far north as Canada while looking for milkweed. A longer migration could result in more butterfly deaths. But even worse is the evidence that higher temperatures could make the milkweeds too toxic for the butterflies to safely eat.
After all, milkweeds contain poisonous components that help make monarchs an unappetizing meal for most other animals. But they are still eaten by some species of birds and mice. Other notable predators include Asian lady beetles and Chinese mantises. There are also a number of parasites that prey upon these butterflies.
A Monarch on Milkweed.
Why They’re Important
Monarch butterflies in particular have cultural significance across North America. Even if you don’t subscribe to the ancient beliefs that they are the souls of the dead or fallen warriors returning home, they are still a powerful symbol of the natural world. After all, even people who don’t generally like insects will often have a special place in their heart for butterflies.
Of course, their value is not only symbolic. Butterflies in general are beneficial pollinators that help many different kinds of food plants grow. They also contribute to the well-being of various habitats along their migration routes. The presence of butterflies is a good indicator of the health of these places. And, if we lose them forever, the world as we know it will be irrevocably altered.
How to Help the Monarchs
Some Easy Steps
-Reduce or eliminate the use of pesticides and herbicides in your yard and garden.
-Immediately clean up any spilled fluids (other than water), particularly those with toxic chemical components.
-Don’t plant the highly invasive black (Cynanchum louiseae) or pale swallow-wort (Cynanchum rossicum) in your yard. These plants are poisonous to monarch caterpillars, but they often mistake them for their favorite foods. Alternatively, if you come across any of these plants on your property, pull them out.
-Create a butterfly garden in your yard. For more information on that subject: go here.
Butterfly Gardens Tips
Dollar stores and similar retailers typically sell inexpensive “pollinator” seed mixes. These provide gardeners with an affordable selection of beneficial plants to grow in their yards. Many public libraries also provide their patrons with a free selection of seeds that may contain some useful plants. You can even get free milkweed seeds by visiting this site and following the steps described there.
Keep in mind that milkweed spreads and some species are pretty aggressive. To avoid losing control of the situation, it might be best to grow these plants in containers. But be sure to keep milkweeds away from livestock, pets, and small children. Remember: these plants exude a toxic sap that helps the monarchs remain unappetizing to various predators.
Also be aware that tropical milkweed (Asclepias curassavica) can be a very problematic plant to include in your garden. After all, it may contribute to the spread of a disgusting parasite (Ophryocystis elektroscirrha) that preys on monarch butterflies. The presence of tropical milkweed can also confuse butterflies into breeding at the wrong time of year rather than migrating when they should. There’s even evidence that high temperatures can cause these plants to become too toxic for the monarchs to consume. Therefore, it’s best to grow native milkweed varieties instead.
Level Up Your Conservation Game
-Take steps to support the creation of butterfly sanctuaries in both Mexico and in the United States. While visiting these places might be on your bucket list as well, low tourism numbers appear to be more beneficial for the butterflies.
-Avoid foods that have been genetically modified and/or campaign to limit their use. Commercial corn and soybean crops are often genetically engineered to withstand heavy herbicide use so that farmers don’t have to do as much weeding. But the end result is that the plants around them (such as milkweed) are also killed.
Be Aware: Some people have gone so far as to raise large numbers of monarch butterflies in their homes in an effort to boost their declining numbers. However, this controversial practice is actively discouraged by scientists for several reasons. Hand-reared butterflies are at greater risk for parasitic infections and they are thought to be less hardy than their wilder counterparts. Their navigational skills may also be affected by this practice.
The truth is when Mother Nature loses, we all do. Without our continued assistance, the monarch butterflies will continue to decline in number until they are only a story that we tell our grandchildren. But if we continue to protect them, the summers for generations to come will still be filled with an orange and black kaleidoscope of butterflies.