12 March, 2016
A carpet of monarch butterflies covers the forest floor of El Rosario Butterfly Sanctuary in Michoacán, Mexico, after a snowstorm. The severe storm hit the mountains of Central Mexico on 8 and 9 March, just as wintering colonies of the butterflies were starting their migration back to the USA—a journey of more than 4,500 kilometers.
The butterflies are surprisingly resilient and can survive several days in sub-zero temperatures as long as they remain dry, but it was unclear how badly the snowstorm affected the colonies. After a general decline in monarch populations, with numbers dipping by 90 percent since the 1990s, there had been a recent increase, and the winter had been seen as a possible turning point for the species.
Jaime Rojo
Jaime Rojo is a photographer and National Geographic Explorer with a background in environmental sciences who specializes in conservation stories about wilderness and wildlife.&n...