Each year, millions of monarch butterflies travel thousands of miles across North America to escape the cold and find ...

The monarch was placed on a waitlist until last December, when the agency formally proposed the butterfly's Endangered ...

The resurgence of the monarch butterfly is proof that when society unites for an environmental cause, results can be achieved ...

The number of monarch butterflies wintering in the mountains west of Mexico City rebounded this year, doubling the area they ...

The population of the eastern monarch butterflies in Mexico doubled this past winter season, according to a WWF survey.

The World Wildlife Fund's latest count of migratory monarch butterflies ... measure individual butterflies but tracks the population by measuring the area that the insects cover in the forests ...

(AP Photo/Marco Ugarte, File) FILE - Monarch butterflies cling to branches in ... but rather the number of acres they cover as they gather on tree branches in the mountain pine and fir forests.

MEXICO CITY -- The number of monarch butterflies ... The annual butterfly count doesn't calculate the individual number of butterflies, but rather the number of acres they cover as they gather ...