The Western monarch butterfly is near extinction. Why care?
The Western monarch is our neighbor. It migrates here to West Marin, as well as to other places along the California coast to overwinter, while monarchs from east of the Rockies migrate to Mexico. In Bolinas, Stinson Beach and the Point Reyes National Seashore, monarchs spend four months huddled together in treetops in a state of partial hibernation. These hibernating monarchs are part of a super-generation that live eight times longer than the typical monarch. To do this, they conserve energy in fat. In early spring, they fly inland to mate and the female lays her eggs on the monarch’s only host—the milkweed plant.
After the tiny egg hatches, the larva or caterpillar eats the milkweed, molts five times and grows 1,000-fold. The caterpillar then hangs upside down and forms a chrysalis, a hard outer casing, where it undergoes a complete metamorphosis: It falls apart, liquidizes and rebirths into a radically different form. Whereas the monarch caterpillar is an eating machine with powerful jaws, the butterfly has no mouth, only a sippy-straw-like proboscis, and flits around with the delicate orange and black patterned wings that are so familiar to us.
This wondrous process happens every year in Marin. At least it used to. Now, the population is in free fall. The California monarch is “on life support,” according to University of California, Davis, entomologist and “butterfly guru” Art Shapiro. From several million counted in 1980, the Western monarch population has fallen below 2,000, a 99 percent decrease, according to Mia Monroe, a ranger at Muir Woods National Monument and a count coordinator for the Xerces Society of Invertebrate Conservation.
Why such a drastic decline? The monarch is losing its habitat, and it is being poisoned by insecticides. As if that wasn’t enough, drought and extreme storms resulting from climate change may prevent flowers from providing nectar at a critical time in its life cycle.
Besides the monarch’s intrinsic value and beauty, it and other insects contribute to our wellbeing in these important ways:
The fragile monarch serves as a canary in the coal mine to alert us to environmental sickness. Monarchs and honeybees could be the first to fall before a collapse. Mary Ellen Hannibal, the San Francisco-based author of “Citizen Scientist,” is clear: “Insect life is at the very foundation of our life-support systems. We can’t lose these insects.”
Monarchs and other insects are pollinators. Monarchs pollinate mostly wildflowers and other flowers. As they suck out the nectar, their legs catch and transfer pollens. Bees and bumblebees are the primary workers, pollinating about 70 percent of our fruits and vegetables. Without pollinators we could be forced to hand-pollinate fruit trees, as many farmers in China do today.
Insects feed birds. Although monarchs may not play a part, many insects are essential dietary components for 96 percent of North American terrestrial bird species, says Doug Tallamy, author of “Nature’s Best Hope: A New Approach to Conservation that Starts in Your Backyard.”
There are ways we can help monarchs and other insects. First, we can grow nectar flowers that bloom in spring, summer and fall. Many natives, such as seaside daisies, asters, verbenas and California fuchsias, have low water needs and a long bloom time. Depending on the season, these plants are locally available at Mostly Natives in Point Reyes Station, at Larner Seeds in Bolinas and at other plant nurseries.
Second, we can plant native milkweed seeds in the fall, or potted starts in the spring—but only if you live further than five miles inland from the coast. Narrowleaf milkweed (Ascelpias fasciularis) is the native to plant in Marin. Do not grow tropical milkweed or other non-natives. Planting too near the coast or planting non-natives can upset monarchs’ migration.
Third, avoid insecticides, pesticides and herbicides. In addition to being lethal to beneficial insects, these chemicals seep into groundwater, toxifying our lakes, streams and aquifers.
Many organizations are working to save monarchs. In 2020, the Environmental Action Committee of West Marin published a monarch report. This led to an ongoing working group with representatives from Marin Audubon Society, Marin Master Gardeners, the Salmon Protection and Watershed Network, the Xerces Society and others.
There are many other ways to help monarchs in our community: volunteering for the Xerces Society’s Thanksgiving count, helping plant school nectar gardens, or joining an online community science group like MonarchWatch.org or iNaturalist.org.
You may wonder—if you grow the right plants, will the monarchs come? How will they know? Female monarchs have taste receptors in their feet that identify milkweed, which contains a latex toxin that renders the monarch unsavory to predators. But besides this crucial plant, monarchs must find a variety of nectar flowers to give them energy for long migrations. As Sir David Attenborough says: “Looking at butterflies in the garden is calming.” They make us happy.
With a little effort by many, we may be able to re-establish the monarch’s habitat, and once again enjoy watching our iconic neighbor in Marin.
Pamela Noensie is a U.C. Marin Master Gardener who filmed and edited the recent YouTube video “How to Save Monarch Butterflies.” She lives in Nicasio.