Tuesday, September 14, 2010
Endemic: it only happens in one place.
Butterflies migrate from Mexico all the way to Canada and back--up to nearly 3,000 miles. This journey occurs over four generations of monarchs in the course of one year since most live only 2-6 weeks. No one knows how each newly hatched caterpillar-turned-butterfly knows to continue the multi-generation migration. The monarch I hatched in 2nd grade was the final generation of the year. It was headed south towards Mexico for the winter.
Sources: http://www.monarch-butterfly.com/, http://www.worldwildlife.org/species/finder/monarchbutterflies/monarchbutterflies.html