Western Monarch


Monarch overwintering in California

Early Thanksgiving Counts Show a Critically Low Monarch Population in California

Published on November 29, 2018

The California overwintering population has been reduced to less than 0.5% of its historical size, and has declined by 86% compared to 2017. While western monarchs are facing unprecedented challenges right now, there is still hope that we can recover the population if we work quickly, strategically, and together.


Monarch flying over showy milkweed, Oregon

Western Monarch Numbers Expected to Be Low this Year

Published on November 15, 2018

You may be asking “What can I do to help the monarch?” Besides protecting habitat, avoiding pesticide use, and planting gardens, another way is to contribute monarch and milkweed data to Xerces-led citizen science efforts—namely, the Western Monarch Thanksgiving Count and the Western Monarch Milkweed Mapper.


Keep Monarchs Wild!

Published on September 11, 2018

Instead of rearing—which is risky and unproven in helping monarchs—we should focus on more effective ways to conserve these glorious wild animals. Our tactics should address the reasons the species is in trouble to begin with. We can do this through taking action to protect natural habitat; to plant native milkweed and flowers; avoid pesticides; support wildlife-friendly, local, and organic agriculture; contribute to research efforts via citizen science; and organize ourselves to push for policy changes.


Very Low Numbers of Monarchs Overwintering in California may Reflect an Unusual Fall

Published on February 1, 2018

The Western Monarch Thanksgiving Count (WMTC) tracks the population of monarch butterflies that overwinter along the Pacific Coast in California and Baja California. Started in 1997, WMTC is one of the longest-running insect monitoring projects in the country. Continuing the tradition, this year, more than 150 enthusiastic volunteers spread out along the coast to find Read more …


New Guidelines for Protecting California’s Butterfly Groves

Published on November 8, 2017

The fact that the monarch butterfly migrates is well-known. The tale of this seemingly fragile creature winging its way across hundreds or thousands of miles enthralls children and adults alike, and has led to a massive level of interest by people everywhere in growing milkweed and other flowers to support this annual cycle. But monarchs Read more …


First New Year’s Monarch Count Completed

Published on June 9, 2017

Volunteers with the Western Monarch Thanksgiving Count have been monitoring the numbers of monarch butterflies overwintering in California every fall for the last twenty years. To better understand overwintering monarch clusters’ persistence during the overwintering season, the Xerces Society and Western Monarch Thanksgiving Count volunteers launched a New Year’s Count in January 2017. The first New Read more …