Monarch Butterfly

Danaus plexippus
Monarch on Milkweed 520x289

Monarchs and Milkweed

Since peak numbers were counted at wintering areas in both Mexico and California in 1997, monarchs have declined by as much as 90% and by nearly 50% compared to long-term averages (  Suspected causes for this decline include; direct mortality from pesticides, climate change and severe weather, destruction and alteration of overwintering habitat from logging and human development, and the loss of millions of acres of its critical food plant, the milkweed, from changes in agricultural practices. Monarchs are completely reliant on plants in the milkweed family, especially members of the genus Asclepias, to complete its life cycle. Adult monarchs use milkweed and other flowering plants as nectar sources to fuel flight and reproduction and they lay their eggs only on milkweeds.  Monarch larvae can only survive by feeding on milkweed. The milkweed plant has a thick white sap that contains latex and cardiac glycoside, a toxic alkaloid. The caterpillar is immune to any harmful effects of the plant but incorporates this toxicity into its body making it unpalatable for many predators.  The use of clean farming and genetically modified crops such as corn and soy bean that allow greater use of herbicides have dramatically decreased the availability of milkweed.  There are 27 species of the milkweed used by monarchs in North American.  In eastern Washington and northern Idaho the only native species of milkweed is showy milkweed (Asclepias speciosa).

What is a milkweed community?

On Turnbull, the milkweed community consists of one species of milkweed, showy milkweed, and those plants and animals associated with habitat conditions where milkweed grows.  Milkweed grows primarily in low areas near wetlands or on north-facing slopes where soil conditions are moister and cooler especially in the spring and early summer. It is seldom found in very dry upland areas or in areas that have standing water in the spring. The presence of very dense grass such as reed canarygrass and shrubs and trees can also prevent the growth of milkweed. It can often grow in areas with adequate moisture that have been disturbed such as farm and hayfields and roadsides. Milkweed is a perennial plant species that establishes easily from windblown seeds. Once established it can spread by underground roots call rhizomes. 

Restoring and Maintaining the Habitat of Monarchs and Other Pollinators

Called the 100 Million Monarchs Initiative, the US Fish and Wildlife Service has set as a goal to increase monarch habitat by 100,000 acres and our region has a 10,000 acre chunk of that goal. To achieve that goal National Wildlife Refuges and the Partners for Fish and Wildlife Program are looking for opportunities to protect, restore and enhance pollinator and milkweed habitat on refuges and private land. Turnbull is doing its part by mapping existing milkweed stands, noting the presence of monarchs and collecting seed in late summer and fall for planting and propagation of seedlings. Staff and volunteers have mapped over 200 locations with milkweed on the refuge, collected over 100,000 seeds and contracted for the propagation of 26,000 seedlings. Six thousand seedlings were sent to other refuges in Washington for planting. 

We received half these seedlings in early June 2015 but conditions were already too hot and dry to plant actively growing seedlings. We were able to plant around 2,000 seedlings with help from a Veteran’s group and our Youth Conservation Corps kids in areas where irrigation was possible or very near to streams and wetlands, but the majority were held over for fall planting when seedlings are dormant.  With the help of school groups from elementary to college age and Girl Scouts, we planted over 7,000 seedlings on the refuge on nearly 5 acres during the fall of 2015. We also planted another 1,200 seedlings on 3 acres of private land.

You too can directly help restore and maintain the habitat of monarchs and other pollinators by participating in organized environmental activities such as a planting day where milkweed and other important nectar producing plants are reestablished. Many schools have environmental clubs, where you could help organize a recycling program or collect money to buy native plant stock, which could then be planted in appropriate habitat. When hiking, biking, fishing, etc. being more aware of these habitat areas and avoiding them will minimize the external factors that deteriorate them (you don’t become the reason for their decline). Unfortunately, many people think of milkweed as a weed and try to eradicate it. You can educate people about the importance of milkweed and other native flowering plants and how to prevent their loss by removal and overuse of herbicides.



Facts About Monarch Butterfly

Wing Span: 3 1/14" - 4 "

Life Cycle: Up to 4 generations/year

Diet:Adults feed on milkweed and other flowering plants; Larvae dependent upon milkweed for survival  

 Migration: Only butterfly known to make a 2-way migration similar to birds

An iconic pollinator species