“During the spring and summer, monarchs breed across the continental United States and parts of Southern Canada, and yet very little is known about where and when monarchs breed west of the Rocky Mountains” (Xerces 2016). In collaboration with partners, the Xerces Society is gathering information about the location of monarchs and milkweed stands in the eleven western states: Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming. There are multiple tools available to report milkweed and monarch observations.

In addition, the Xerces Society has “created guides to the native milkweeds of California, Nevada, Oregon, Washington, and the Great Basin to help identify milkweeds in your region […] The data collected from these efforts is being used to help the many agencies and organizations engaged in monarch conservation. This includes understanding where and when monarchs breed, as well as planning where planting milkweed and nectar plants would be most effective. The data has also been used to develop a habitat suitability model for monarchs through our partnership with the Pacific Region of the US Fish and Wildlife Service” (Xerces 2016).

• Xerces Society for Invertebrate Conservation. 2016. Documenting milkweed (Asclepias spp.) and monarch distribution across the western US. xerces.org/milkweedsurvey/.

Keywords: habitat, mapping, milkweed, survey, western monarchs