Documenting milkweed (Asclepias spp.) and monarch distribution across the western U.S.

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. The Xerces Society and others are working to change this situation, and we could use your help!

Check out the new platform for accessing and contributing milkweed and monarch observations in the West:

Western Monarch Milkweed Mapper

 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 habitat suitability models for milkweeds and monarchs through our partnership with the Pacific Region of the U.S. Fish and Wildlife Service (USFWS) with a new iteration of the model underway in early 2017. The more data collected, the more accurate this model will be to help identify areas where milkweed plantings and monarchs will flourish. Thanks for supporting monarch conservation! Contact monarchs@xerces.org with any questions.

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