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News: Population Trends

Measuring Monarchs and Milkweed

Monarch population size estimates allow us to assess the status of the population, and set goals for restoring it to a sustainable level. Monarchs’ declining numbers have gained a lot of attention, but how is the monarch population measured anyway?  Read More »

Eastern Monarch Population Numbers Drop 27%

This year’s measurement of the eastern monarch overwintering population showed a 27% decrease compared to last year, occupying 2.91 hectares of forest in Mexico’s transvolcanic mountains during the winter of 2016-17.  Read More »

Western Monarch Count Reports More Monarchs than 2015, but Numbers Remain Low

The 2016 Western Monarch Thanksgiving Count population survey has reported 298,464 western overwintering monarchs from 253 monitored overwintering sites across the California coast.  Read More »

New Publication Reveals Birthplaces of Eastern Monarchs

A recently published study (Flockhart et al. 2017) builds on previous work describing the natal origin of eastern overwintering monarchs, and has new implications for monarch conservation.  Read More »

Road Tripping for Monarchs in Utah and New Mexico

There are blank pages in the monarch butterfly book in the western United States. This summer the Southwest Monarch Study, with support from the Monarch Joint Venture, has been working to fill them.  Read More »