Picture of monarch butterflies (Danaus plexippus) taken on December 10, 2008 at the Sierra del Chincua sancturay in Angangueo, in the Mexican state of Michoacan. Millions of monarch butterflies arrive each year to breed at the Oyamel forest in Angangueo, after travelling more than 4,500 kilometres from the United States and Canada. AFP PHOTO/Mario Vazquez
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