"The monarch butterfly, one of the most seemingly delicate of all of nature's animals, proves to be one of the toughest in this reader. With bold, colourful photographic illustrations and covering a wide range of popular non-fiction subjects, 'National Geographic Readers' stand out in the market for their widespread appeal with both boys and girls. Making the yearly trip from the Northern United States and Canada to the Oyamel forest of Mexico is no easy task, and it takes five generations of butterflies in order to do so. Battling cold temperatures and the threat of starvation, these beautiful insects complete an almost 3,000 mile journey over the course of two months, only to have to turn and around and head back home." -- publisher.