Grounded Butterflies
Although they appear lifeless, grounded butterflies may only be immobilized by the cold. Monarchs can't fly unless they can warm their muscles to 55°F. They can't even crawl below 41°F. Although monarchs can save energy when they are cold, the cold also makes them vulnerable.

"If buried by snow, monarchs might stay on the ground under the snow for more than a week," notes Dr. Bill Calvert.

Estela Romero