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

Monarch butterflies only flap their wings around 5 to 12 times per second — much more slowly than the average butterfly, who flaps about 20 times a second. In the right conditions, a migrating monarch ...

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

The natural phenomenon of the iconic monarch butterflies migrating south for the winter is a fascinating one - and it's one that's under threat.

A monarch butterfly gliding over a field on outstretched ... female landing and reaching her abdomen down to deposit a single golden, cone-shaped egg on the underside of a leaf.

The survey began in 1997 Monarch butterflies, known for their distinctive orange-and-black wings, are found across North America. Monarchs in the eastern United States spend their winters in ...

The Western population of the monarch butterfly hit a near-record low with fewer than 10,000 found living in California this winter, a foreboding sign.