Highflying Geese Save Energy By Swooping Like a Roller Coaster

"The bar-headed goose is famous for its long, annual migration from the Indian subcontinent to central Asia, a flight that takes it over snowcapped Himalaya Mountains so high and dangerous that human climbers struggle just to stay alive."

"Scientists had thought these birds might fly up to a high altitude and then stay there for the trip, much like a jet plane. But a study published Thursday in the journal Science shows they actually fly close to the ground, going up and down through the mountains like a roller coaster."