Partnering to conserve the monarch butterfly migration

FAQs from Webinars

Monarch Biology and Conservation Basics – Question Summary

Here are brief answers to a number of questions that were asked in the Monarch Biology and Conservation Basics webinar on December 17. Sorry if we missed your question. If you have any additional questions, feel free to direct them to

Do monarchs utilize different types of milkweed? Which are preferred?

Will they use all types of flowers for nectar, or are there specific types of flowers that they use for nectar sources?

  • Adult monarch nectar from a variety of blooming plants. Most importantly, make sure that there is nectar available throughout the growing season by providing a highly diverse foraging area. Some species are favored over others, depending on your region.

Can you elaborate on Florida monarchs? 

  • There is a non-migratory population of monarchs in the southern tip of the state, since milkweed is able to grow year-round in this location. During spring and fall migrations, there may be some exchange of genetic material as eastern North American monarchs are migrating may end up in the south Florida population rather than in Mexico.

It is my understanding that there is some mixing of eastern and western populations in wintering areas, is anyone measuring the amount of mixing?

  • No

How much impact is logging and other issues with winter habitat having?

  • In 1986 a decree was set in place to protect the Monarch Butterfly Biosphere Reserve, which has reduced the amount of illegal logging significantly. Read more about threats to the overwintering sites in the North American Monarch Conservation Plan (pg 24)

What are butterfly survival rates for the fall migratory generation from north to south (eastern migratory population)?

  • Warrants further research.

Do we understand site characteristics necessary for successful transplanting milkweed?

How many generations does the western monarch population see annually?

  • Typically 4, same as the eastern population. They usually break up from the overwintering sites in California in mid-February and arrive beginning late October.

Do we know if offshore islands are important stopover habitats (fall and/or spring)?

Many of us are now facing acreage expectations for increased milkweed production.  Could we talk management and habitat conditions necessary to increase needed host plants.  Ex. How far apart should they be planted?

  • Management and restoration will be covered in an upcoming webinar. Stay tuned!

How do we connect with a citizen science group?

Are the western and eastern populations genetically isolated, or can they "mix in the middle" during their northern migrations?

  • There is some interchange.

Can you please describe recent tri-national efforts and strategies related to monarch conservation? What is the big picture on these collaborative efforts at this point?

  • There is a U.S. High Level Working group for monarchs working on a national strategy. This group will work collaboratively with working groups in Canada and Mexico to develop a trinational action plan for monarch conservation.

Do you have information on mosquito control and monarchs?

Are there natural enemies that kill monarch eggs, larvae, and adults?

People say there is 'enough' milkweed in Ontario, so we don't need to plant more here.  Is that true?  Is there ever 'enough'?

  • Habitat for monarchs is also benefiting a variety of other pollinators, therefore there is never enough habitat. Plus, habitat fragmentation makes it difficult for monarchs to find suitable breeding areas, so an abundance of habitat ensures that they will find habitat more easily. Recovering from record low populations may not happen in one year, so the more habitat available for reproduction, the better likelihood monarchs have of a population rebound.

Is there any value of habitat that has nectar sources but no milkweed sources for monarchs?  Or, is the push really to focus on milkweed in the habitat?

  • During the northward migration and throughout the breeding season, milkweed is the priority component for habitat. However, in addition to milkweed plants, nectar sources are extremely important for adult monarchs. Nectar sources are of high priority during the fall migration, when milkweed is not needed. All habitat restoration efforts should plan for both milkweeds and nectar sources.

Do native species seed mixes commonly contain local milkweed?  Or, do you have to look for more specific native species seed mixes that do include milkweed?

  • More on seed mixes in an upcoming webinar.