Of all migrations by small creatures, few are as astonishing as the one performed by the Monarch butterfly. The embodiment of fragility, they travel between 1,200 and 2,800 miles or more between their starting and ending points -- a feat without parallel. What is even more remarkable is that the ones that return to the places where Monarchs hibernate have never been there before. These are the great-great-great-grandchildren of those that performed the intrepid journey ... - 摘自世界野生动物协会网站