New paper - Host Plants and Climate Structure Habitat Associations of the Western Monarch Butterfly

Matt Forister, myself, and our collaborators at the Xerces Society and the USFWS have a new paper out titled "Host Plants and Climate Structure Habitat Associations of the Western Monarch Butterfly" which is published in the journal Frontiers in Ecology and Evolution. In this paper we model the habitat associations between monarch butterfly, their milkweed host plants, and a number of climatic, topographic, land use, and soil variables. We also perform habitat modeling for 13 of the most common milkweed species in the western U.S. Our study is the first large-scale habitat modeling study focused on the western population of the monarch butterfly which overwinters on the California coast and migrates inland towards the Rocky Mountains. Our paper is open access meaning that anyone can read and download it. You can go to it by clicking HERE.

To facilitate this kind of modeling we used an online citizen-science mapping tool called the Western Monarch and Milkweed Mapper. You can use the WMMM to upload your photos of monarchs and milkweeds in order to help us build better models in the future!  The WMMM also flags recent monarch sightings so that you can see when the monarchs are arriving in your area.  The WMMM also has great resources for learning how to identify the different species of milkweeds.  You can access the Western Monarch and Milkweed Mapper by clicking HERE.

Our habitat modeling work was also made possible by the tremendous amount of legwork by Madeline Steele and Joe Engler (USFWS) who completed a first version of these habitat models in 2016. Most of the variables that we used were originally compiled by Madeline, and the methods that we used followed Madeline's approach.

Finally, we should note that we have made high-resolution maps as well as details about the methodology available in the supplementary material. I would encourage you to check out these resources. For GIS users we have GeoTIFF versions of our maps available. Please contact me and I will send you a link to these files.

Citation: Dilts, T.E., Steele, M.O., Engler, J.D., Pelton, E.M., Jepsen, S.J., McKnight, S.J., Taylor, A.R., Fallon, C.E., Black, S.H., Cruz, E.E., Craver, D.R., & Forister, M.L. (2019) Host plants and climate structure habitat associations of the western monarch butterfly. Frontiers in Ecology and Evolution, 7, 188.

Western Monarch and Milkweed Mapper - a great tool for all citizen scientists

I'd encourage everyone to visit the Western Monarch and Milkweed Mapper to log your monarch and milkweed sightings.  The website is maintained by the Xerces Society, and the data contained withing it has been the primary source of data for our habitat mapping effort.

https://www.monarchmilkweedmapper.org
https://www.monarchmilkweedmapper.org/habitatsuitabilitymodels/

This morning I had the opportunity to join my daughter's second grade field trip to Betsy Donnelly Park where we spotted 3 narrowleaf milkweeds and 1 showy milkweed.  I logged them on the mapper.

There will probably be a huge rush of data as the professional scientists post their findings this fall, but it is really exciting and interesting to see monarch sightings in real time, so I'd encourage all of you citizen scientists and monarch lovers to post throughout the season.

Monarch butterfly and milkweed models the western U.S.

Today Matt Forister and I presented the results of our habitat modeling work for monarch butterflies and milkweeds for the western U.S. I've been involved in this research now since January 2017 and am very excited about having some preliminary maps and models ready. The work is an extension of the 2015 habitat modeling effort by Madeline Steele while she was at the U.S. Fish & Wildlife Service. Our work is a collaborative effort by University of Nevada Reno, the Xerces Society, the U.S. Fish & Wildlife Service, and others. I'm excited to get to work with such an iconic species, and I hope that through conservation and societal awareness of pesticides we can halt the decline of one of the most beautiful insect species in the world.