The monarchs we see in Chicago are part of the eastern population, which accounts for nearly all the monarchs in North America, and includes a supergeneration that flies thousands of miles to Mexico. The western population, which winters in California, was found to number fewer than 2,000 monarchs in a Thanksgiving count — a record low, down from nearly 30,000 the prior year and more than a million years ago.
Monarch butterfly population down so it’s not too early to plan your urban monarch garden, local researchers say
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