Migrimi i fluturave monark

Monarchs cluster together for warmth in a Mexican overwintering site. (Credit: Jaap de Roode)

Monarchs take to the sky in Mexico. (Credit: Sonia Altizer)

Monarch butterflies catching the sun on an oyamel tree in a Mexican overwintering site. (Credit: Jaap de Roode)

A monarch butterfly about to emerge from its chrysalis. (Credit: Jaap de Roode)

White and orange monarchs from Hawaii raised by biologist John Stimson in the 1980’s. (Photo credit: Wei Zhang)

Scientists have discovered the gene responsible for the monarch's bright orange color, a warning sign to predators. (Credit: Pat Davis)

Monarchs arrive in Mexico after the long journey from eastern North America. (Credit: Natalie Tarpein)

University of Chicago Assistant Professor Marcus Kronforst hunting butterflies on the university campus. (Credit: Robert Kozloff)

The population of migrating monarchs that reach Mexico each year has dropped dramatically in recent years because of habitat loss, decline in food source and changes in climate. (Credit: Natalie Tarpein)

Milkweed, the primary food source for monarch butterflies, has dropped in recent years mirroring the decline of the insect. (Credit: Creative Commons © jungle mama)