Monarch butterflies officially listed as endangered

Monarch butterflies are now officially listed as endangered because of fast dwindling populations in North America.
The International Union for the Conservation of Nature announced the designation on Thursday for the orange-and-black butterflies.
The group estimates populations have declined between 22% and 72% over the last decade. After wintering in central Mexico, the butterflies migrate north to Canada.
They breed new generations along the way that begin the return trip at the end of summer. But the butterflies have become more and more imperiled by loss of habitat and increased use of herbicides and pesticides for agriculture, as well as climate change.