Monarch butterfly populations see sharp decline this season

Cold, wet weather in the U.S., illegal deforestation in Mexico, and strong herbicides used on genetically altered crops in the U.S. and Canada are, warn scientists, threatening the survival of the monarch butterfly. Researchers say the number of monarchs that made it to their forested, hilly wintering grounds in Mexico this winter was the lowest since record keeping began about 30 years ago, some 75 percent lower than last year. “There used to be rivers of butterflies, but now there are years when there are no butterflies at all,” says Homero Aridjis of the area near his village. He helped set up monarch sanctuaries in the 1980s and calls the current decline in population numbers a “trinational crisis,” referring to the three countries — Mexico, the U.S., and Canada — through which the orange and black insects migrate thousands of miles. Although monarch butterflies are known to be quite resilient following years of die-off, biologists say the continued habitat destruction throughout their migratory path may cause numbers to drop so low that the population will be unable to recover.