What sounded like leaves rustling in the wind was the flickering wings of thousands of monarch butterflies as they flitted ...

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

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

This year’s count of 4.42 acres of occupied forest habitat is nearly twice as large as last year's, but eastern monarch ...

Millions of black and orange wings will flutter across the U.S. this spring, as the monarch butterflies make their annual ...

and is seen in species as varied as monarch butterflies, caribou, and baleen whales. The main source of energy used for migration is fat. Fat stores about 8–10 times more energy than the ...

Mexican officials and environmental groups say better weather conditions on the butterflies’ migration route caused the ...

Colony estimates at central Mexico overwintering sites indicate that monarch butterfly (Danaus plexippus) populations have declined over the past two decades. Among the leading causes of this ...

Monarch butterflies -- including western monarchs ... their chrysalises when conditions are no longer suitable for fall migration. Though the field survey showed that monarch arrival times ...

A new study, involving researchers from the Institute of Science and Technology Austria (ISTA), suggests that the butterflies’ varying migration distances are influenced by environmental factors ...

These butterflies take a break here during their migration every winter, from November to January. They behave similarly to monarch butterflies, which travel 4,000 kilometres from Canada to Mexico ...