The butterflies overwinter in the forests of the sacred fir trees ( Abies religiosa) at high altitudes. However, these forests that the monarchs need to survive their migration are at risk due to climate change.

The migration of the monarch butterfly is one of the wonders of the natural world. Each autumn, a new generation of monarch butterflies is born in the northern United States and southern Canada. Hundreds of millions of these butterflies then fly to the mountains of Central Mexico,

Climate change could wipe out monarchs' winter habitats by 2090, but an ‘assisted migration’ strategy aims to build new environs they could call home.