Air Date: Jun 04, 2014 12:00 AM ET
Over recent years, monarch butterfly numbers in North America have been in massive decline. But new research suggests we may have been getting the reasons for the drop in numbers all wrong.
Top News Headlines
- Parents consult lists of the living and the dead after earthquake destroys school in Mexico City
- Mexico quake rescuers search school rubble, 52 people saved from collapsed buildings in capital
- Maria the worst hurricane to hit Puerto Rico in 80 years
- Canada running to keep up with fast-moving developments in self-driving car technology