Back to this week's update.

They're Here!
Estela Romero reports the big news: "Karlita registered the official arrival date for all of you in the U.S. and Canada to see: Sunday, October 23rd." Just think: The monarchs arriving now are probably the great-great grandchildren of the butterflies that left Mexico last spring. Millions more are flying to this specific point on our planet, a place none has been before. It's miraculous to realize they are guided by their genetic code, passed down through generations.

Monitoring the monarch butterflies' arrival in Angangueo, Michoacan