Not a Bird, Not a Plane

Some dreamers chase butterflies. FRANCISCO GUTIERREZ pursues them through international airspace. This fall the Mexican hang glider flew more than 4,000 miles, following the annual migration of the monarch butterfly from Montreal to Mexico's Michoacán state in his ultralight plane. Gutierrez, 44, spent six years planning his 10-week trip and securing funding for a documentary about it in order to draw attention to the logging and pesticide use that threaten the monarch. Gutierrez overcame hardships insects don't face--like understanding foreign air-traffic controllers and fixing an overheated engine. But, now back on the ground, he says he kept the mood light. "I...