Climate change, loss of habitat decimating monarch population; but Petalumans can help

Like the honey bee, the monarch butterfly may be facing extinction. The milkweed patches that they rely upon have been decimated. Native milkweed is essential to their survival and local monarch enthusiasts are calling on the public to leave the milkweed be, or better yet, plant it. While you’re at it, throw in some native blossoms.

Local master gardener and monarch expert Suzanne Clarke says monarch butterflies are fascinating.

“The monarchs are the only insects that will migrate from Canada to the California Coast, and on the East Coast, migrate between Mexico and Canada,” she said.

Clarke explained that the monarchs overwinter as adults whereas all of the other butterflies will spend the winter as caterpillars or chrysalises.

“I found it absolutely fascinating that the monarchs that emerge from their chrysalis in October (and) November will emerge with unripe sex organs,” Clarke said. “That’s why they were able to stay as adults over the winter and then in spring when it gets warmer they will be ready to mate.”

But the numbers are dropping dramatically. Just 1,914 monarch butterflies were counted across 261 overwintering sites, according to the Xerces Society’s 2020 Western Monarch Thanksgiving Count.

Clarke is the founder of the Sonoma County Butterfly Alliance and participates in the count. She has also provided waystation gardens for monarch butterflies for years, creating significant habitat for them. Local waystation gardens are helping create a web of habitat for monarchs and other species. There’s also an opportunity to help scientists track the monarchs’ flight patterns and more.

When asked what she thought was impacting the monarch populations, Clarke didn’t hesitate.

“Number one is climate change,” she said. “The weather can either be too wet or too cold. Over the last few years we’ve had these terrible wildfires as the monarchs are migrating back toward the California coast.”

Adult monarchs need nectar from flowers. Monarch eating habits change with the different stages of its life, doubling the food requirements for its habitat.

The monarch caterpillar needs milkweed to eat or it will starve. Adult monarchs lay their eggs upon the plant itself.

“Monarch females will only lay eggs on the milkweed plant,” Clarke said. “Spraying to kill the milkweed plant results in habitat loss for the monarch butterfly.”

When new development destroys patches of milkweed, the seemingly innocent act of cutting down a weed is actually destroying monarch habitat.

As a master gardener, Clarke advises locals on plants that help butterflies.

“Native pollinating flowers are the best because insects and flowers have co-evolved to fulfill each other’s needs,” she said. “Asters, salvias, sages, penstemons, and milkweed itself is a great pollinating plant.”

Showy milkweed and narrow leaf milkweed are native to the local area and therefore will be beneficial to the local ecosystem. Introducing new species can result in increased parasites or diseases because natural selection was not allowed to weed out the strongest for the area. In this we are reminded again of the intricate balance of nature.

The U.S. Fish and Wildlife Service also stresses the importance of planting native milkweed, local to your area. On its website, the agency sets out to debunk false ideas, noting, for instance, that monarch caterpillars eat only milkweed and therefore pose no threat to nearby plants.

They also noted that although milkweed is toxic in large quantities, it has a very bad taste, and animals won’t eat it unless they were very hungry. Making sure there’s another food source close by for animals and instructing children that the plant is poisonous are suggested as good precautionary practices.

Even if you can only do potted plants, providing pollinating blossoms is helpful. If possible, create a sunny spot where monarchs can pause and warm their wings after a long sip of nectar.