Western Monarch Milkweed Mapper

The Western Monarch Milkweed Mapper project is part of a collaborative effort to map and better understand monarch butterflies and their host plants across the Western US. Data compiled through this project will improve our understanding of the distribution and phenology of monarchs and milkweeds, identify important breeding areas, and help us better understand monarch conservation needs. Some of the key research questions that these data will help us answer include:

• Where are different milkweed species growing in the West?
• Where are monarchs occurring in the West?
• Where are monarchs breeding in the West?
• When is milkweed emerging and senescing (dying back) in the West?
• How does milkweed phenology (life cycle) differ by species?
• When is monarch breeding occurring in specific areas/regions of the West?
• What types of habitats are different milkweed species associated with?

How Can You Help?

Your help is critical to the success of this project! Because monarchs and their host plants are found all across the western US, the best way to document them is to engage a multitude of volunteers and their cameras. You can participate in this effort by using this website to:

• Upload your photos of monarchs and milkweeds;
• Identify milkweeds using our milkweed key, which profiles over 40 milkweed species found in the west;
• Submit data which will help researchers determine the distribution, phenology, and conservation needs of monarchs and milkweeds in the west; and
• Learn about monarchs, their host plants, and ongoing conservation efforts for these species.

Participating in this project is simple and you can get started now by creating an account by clicking on the link above under Website. Once you have an account, go out and start looking! Check your local parks, natural areas, gardens, and even roadsides. We’re looking for all stages of monarchs, so don’t forget to look at milkweed leaves and stems to see if caterpillars or eggs are present. Snap a few photos and then sign in and submit your data via our Milkweed and Monarch Sightings forms. Have fun while learning more about monarchs and the special habitats they use in your area!