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2012-13 Overwintering Population Report

May 01, 2013


  • Population Trends

Longer days and warming temperatures spark the growth of milkweed across the country, corresponding with the journey of the spring monarchs to the northern breeding range. The bleak outlook for the spring 2013 migration was reinforced by the March 2013 release of the population status report from Mexico , which documented a record low population, occupying only 1.19 hectares. There were 9 overwintering sites that were monitored throughout the winter and measured to estimate the population. Scientists estimate about 50 million monarchs per hectare of forest occupied.

This report brought great concern—about why the decline is happening, and what can be done to reverse it. There has been a surge of press releases, interviews, and social media activities aiming to raise awareness about the monarch decline and what to do to help. In addition to planting milkweed and nectar plants for monarchs during the breeding season, volunteers can help us to understand population trends and factors influencing the decline by monitoring for citizen science projects.

To read more about the 2012-13 overwintering report and outlook regarding the 2013 monarch breeding season, visit Monarch Watch's blog page to read Chip Taylor's article Monarch Population Status