Skip to main content

NATIVE MILKWEED FOR MONARCH BUTTERFLY RECOVERY

P1110033
Monarch butterfly on showy milkweed
Monarch butterflies are an iconic species. Many people remember a time when they were omnipresent in the summer in the United States, but times have unfortunately changed as the monarch butterfly faces more threats to their survival than ever. The monarch butterfly is known by scientists as Danaus plexippus, which in Greek literally means “sleepy transformation.” Monarchs that live east of the continental divide embark on a spectacular annual migration to winter roost sites in oyamel trees in the mountains of Michoacán, Mexico. The World Wildlife Fund explained the results of a recent survey of monarch populations as follows: “A new survey of migratory monarch butterflies at their wintering habitat shows a 69% increase in the area they occupied this winter in relation to last year’s winter. Yet this is still the second smallest area occupied by these butterflies in Mexican sanctuaries since 1993.
Monarch eggs on Showy milkweed
Monarch eggs on showy milkweed
Monarch butterflies, which hibernate in Mexico, migrate between 1,200 to 2,800 miles from Canada and the United States to establish their colonies in temperate forests in the outskirts of Michoacán and the State of Mexico. The forest area occupied by these colonies serves as an indirect indicator of the number of butterflies that come to Mexico.
Monarch caterpillar on Showy milkweed
Monarch caterpillar on showy milkweed
To survey these colonies, biweekly trips were made to colonies with a historic presence of butterflies, and the location and perimeters occupied by monarchs was determined using a spatial analysis software. The study was carried out by the WWF-Telcel Alliance and Mexico’s National Commission of Protected Natural Areas. In total, nine monarch butterfly colonies were recorded, both inside and outside of the Monarch Butterfly Reserve. “The 2.79 acres occupied by monarchs this season should serve as additional motivation for the leaders of Canada, Mexico, and the United States to translate the commitment they made in Mexico in February 2014, to concrete and immediate actions”, said Omar Vidal, Director General of WWF in Mexico. “It is crucial that we restore and protect the habitat of this iconic species in all three countries, but above all that we limit the use of herbicide and land conversion in the United States and maintain efforts to avoid deforestation in Mexico,” he added.”
Pismo beach, California monarch grove. Monarchs on Monterey cypress tree.
Pismo beach, California monarch grove in January. The monarchs are on a Monterey cypress tree.
Monarch butterflies that live west of the continental divide, however, including monarchs that migrate through the Klamath-Siskiyou bioregion, overwinter in various groves of trees along the central and southern California coast. The International Environmental Law Project released a report in 2012 entitled, The Legal Status of Monarch Butterflies in California, which states that “observations from annual counts of overwintering butterflies in California reveal monarch population declines of approximately 90 percent across most sites with some sites faring significantly worse.”
Pismo beach, California monarch grove in January. Monarchs on non-native eucaplyptus trees.
Pismo beach, California monarch grove in January. Monarchs are on non-native eucalyptus trees.
There are many reasons for this significant decline, including agricultural and urban development, pesticides, logging of overwintering habitat in Mexico, climate change, and loss of milkweed, the main food source for monarch larvae. The following quote from the Center for Biological Diversity’s shows the obstacles the monarch butterfly is currently facing: “The heart of the monarch’s range is the midwestern “Corn Belt,” where most of the world’s monarchs are born on milkweed plants growing in agricultural fields. Because of the ubiquitous spraying of Roundup on corn and soy that have been genetically modified to resist herbicides, the monarch is in bad trouble in the core of its range, where its sole host plant, milkweed, is disappearing. In a one-two punch, climate change is undermining the stable weather conditions and predictable flowering seasons that monarchs need to complete their migration. Climate change also threatens these butterflies’ overwintering habitat in the mountain forests of Mexico. Just as Joshua Tree National Park will soon no longer support Joshua trees, the International Monarch Reserve in Mexico is expected to become climatically unsuitable for monarchs by the end of the century.”
Monarch chrysalis on Showy milkweed.
Monarch chrysalis on showy milkweed.
Milkweed has long had a bad rap because of its potential toxicity to livestock. Many farmers consider the plant a weed and either spray it with herbicides or simply plow it under; however, female monarch butterflies lay their eggs exclusively on the leaves of milkweed plants. These host plants are the only food that monarch caterpillars will eat. As the caterpillars ingest milkweed the toxins in the plant are stored in their bodies, making the caterpillars and adults toxic to many predators.
Showy milkweed (Asclepias speciosa)
Showy milkweed (Asclepias speciosa)
The Klamath-Siskiyou bioregion is home to three native species of milkweed: Showy milkweed (Asclepias speciosa), Narrowleaf milkweed (Asclepias fascicularis), and Purple milkweed (Asclepias cordifolia). Showy milkweed can be spotted along roadsides, in drainage ditches, in unplowed fields, and other locations within the valley bottom. This species ranges from the Midwest to the west coast and north into Canada. This is the largest of the milkweed species in the Klamath-Siskiyou and the most common.
Narrowleaf milkweed (Asclepias fascicularis)
Narrowleaf milkweed (Asclepias fascicularis)
Narrowleaf milkweed has a long, narrow leaf and small, pale pink flowers with a distribution that includes most western states down to Baja California. This plant is rhizomatous and spreads readily. It prefers to grow in full sun in dry or moist conditions. It can also be found in abandoned or unplowed fields and along roadside ditches in low elevation habitat. Purple milkweed is a spectacularly beautiful species that is native to parts of California, Nevada and Oregon. Purple milkweed has a more dispersed distribution within the Klamath-Siskiyou than the showy or narrowleaf milkweed and is less well known. Purple milkweed prefers to grow on rocky slopes or outcrops in woodland and coniferous forests. Native Americans used the fiber in milkweed plants for the creation of ropes and nets. Anthropologists found a 40 foot long deer net made from purple milkweed that required an estimated 35,000 plant stalks to construct.
Purple milkweed (Asclepias cordifolia)
Purple milkweed (Asclepias cordifolia)
The monarch population continues to decline at an alarming rate. If we don’t act soon to increase, protect and restore monarch habitat we may see the population of this majestic and iconic species dwindle. Consider planting milkweed for monarch butterfly recovery; you will be glad you did. Within a short time the monarchs will find your patch of milkweed and begin using it for their reproduction and migratory needs to insure their survival into the future. You may not personally be able to do much to help other endangered species, like polar bears for instance, but there is a tangible thing you can do to help the endangered monarch butterfly: plant milkweed! You can help an endangered species right in your own backyard.
Monarch caterpillar
Monarch caterpillar
Responding to a petition from environmental organizations and butterfly advocacy groups, the U.S. Fish and Wildlife Service (USFWS) opened a “status review,” a step in the right direction toward future recovery of monarch butterflies. This week marks the end of the public comment period for the status review, in which the USFWS was asking for public input on whether or not monarch butterflies warrant endangered species protection. Let’s hope the USFWS does the right thing and lists the monarch as an endangered species under the Endangered Species Act. Klamath-Siskiyou Native Seeds currently has both showy milkweed and narrow leaf milkweed seeds for sale. Hopefully next year we will also add purple milkweed to our inventory.
Showy milkweed (Asclepias speciosa) seed
Showy milkweed (Asclepias speciosa) seed
To view a photo essay of the monarch butterfly lifecycle in the Klamath-Siskiyou, see a blog post we wrote for The Siskiyou Crest Blog at:  http://thesiskiyoucrest.blogspot.com/2014/07/monarch-butterflies-in-siskiyou_4.html