The population wintering in central Mexico's forests occupied 4.42 acres, up from 2.22 acres during the previous winter.

A Pennsylvania butterfly farmer says listing the monarch as a threatened species could do more harm than good.

A sweeping new study reveals that butterfly populations across the continental United States have plummeted by 22% over the ...

The plant has been disappearing due to drought, wildfires, herbicides and urbanization. In December, the U.S. Fish and Wildlife Service proposed that monarch butterflies receive protection as a ...