Historically monarchs across U.S. grasslands would have numbered in the billions. In the late 1990s the clustered butterflies covered 45 acres of fir trees in their overwintering forests in Mexico, ...

Collected from some of the best-known photography competitions around the world, here are the most captivating nature photos ...

For a monarch butterfly, the more white spots you have ... Once they've arrived, they huddle together at high altitude in Oyamel fir trees, often blanketing them completely.

Citizen scientists are called on to help with tagging monarch butterflies and find out why their numbers are dropping.

The Butterfly Trees is a documentary feature film ... forested shores of Southern Canada to the rare and ancient oyamel fir trees of Central Mexico Part science part adventure and part love ...

Making a stand In 2017, Sáenz-Romero and colleagues gathered seeds from cones from eight stands of sacred fir in the Monarch Butterfly Biosphere Reserve (MBBR) in Mexico, at altitudes between ...