大象传媒

On the shores of Lake Erie in Canada, a chill wind beckons the beginning of winter. Resident monarch butterflies must fly south to warmer climes as they would not survive the winter months here. Fuelling up on nectar before the long journey begins, the monarchs must fly for more than 2,000 miles to a secluded valley in Mexico, where it will hibernate with countless others until the warmer spring air comes. But hibernation leaves the butterflies vulnerable to predators that pick some off for food and dislodge others in the process. Those that fall to the floor have to get back to the trees before nightfall, or they will fall prey to the cold ground frosts of the forests.