I just finished Barbara Kingsolver’s “Flight Behavior,” a heart-wrenching story about monarch butterflies, their migration and the destruction of their habitat. Although fictional, the author provides detailed scientific information about their physiology, migratory behavior, food sources and how scientists study these amazing creatures called “King Billies” in the book.
Monarchs born in September and October migrate from cold weather climes to Mexico or California. Butterflies born east of the Rockies head to Mexico and those born west of the Rockies go to California. They can travel 2,500 miles to get to their wintering location and are the only butterflies to do so. Each year they go back to hibernate in the same trees used by prior generations. They return north in the spring to find larval food, primarily milkweed.
Unfortunately, these amazing butterflies are in trouble. Populations have decreased significantly over the last 20 years according to the U.S. Fish and Wildlife Service (FWS). The FWS is looking at whether monarch butterflies warrant Endangered Species Act protection. Habitat loss and fragmentation threaten their survival. For example, a huge mudslide wiped out all the trees in one wintering site in Mexico. A changing climate has intensified weather events which impact populations’ food sources, their overwintering sites and whether they can migrate successfully. The 2017 Western Monarch Thanksgiving Count led by the Xerces Society for Invertebrate Conservation counted 192,629 monarchs. This was the lowest number observed since 2012, and was notably down from 2016 when slightly fewer than 300,000 overwintering butterflies were tallied along the California coast. Sadly, in 2018 the count was only 20,456 butterflies. Twenty years ago, the count was 1.2 million monarchs wintering in California (www.fws.gov/savethemonarch/).
As gardeners, we can help by growing pollinator gardens filled with a diversity of nectar-rich native perennial flowers that bloom successively through the seasons for monarch adults and milkweeds to feed monarch caterpillars. These flowers do best on a sunny site, which will also allow the butterflies to bask in the sun. Avoid all insecticides and other pesticides.
Here is a Cooperative Extension publication covering plant materials for pollinators http://www.unce.unr.edu/publications/files/ho/2014/sp1407.pdf.
Another exceptional publication designed for our Great Basin gardens is put out by the Xerces Society www.nwf.org/~/media/PDFs/Garden-for-Wildlife/Xerces-NWF/05-Great_Basin_Monarch_Plant_List_spread.ashx.
Some suggested plants that benefit monarchs in particular include penstemon, cleome, wallflower, giant hyssop, sunflower, sulfur-flower buckwheat.
Let’s all do our part to help this threatened species survive.
JoAnne Skelly is associate professor and Extension educator emerita, University of Nevada Cooperative Extension. email@example.com.