Is extreme weather to blame? steveburt1947/Flickr In the summer of 2011, a small band of Ontario scientists set out to perform the most ambitious survey ever attempted of the imperiled monarch butterfly. Leading the fieldwork was Tyler Flockhart, a Ph.D. candidate at the University of Guelph, who trekked nearly 22,000 miles through the United States and Canada to bag and tag hundreds of butterflies, which were then put under a lab analysis to determine their birthplaces. “As far as I know, it’s the broadest sample of monarch butterflies through an entire breeding season across North America,” Flockhart said recently. The results of the endeavor confirmed what entomologists have fretted about for years: Everyone’s favorite butterfly seems to be fluttering on the road toward extinction. “They’ve been declining steadily,” said Flockhart, to the point that 2012 their population numbers in their Mexican winter home were at the lowest point on record. Tracking these fairylike insects is a dicey proposition because their yearly migration spans vast distances and involves several different generations. The butterflies spend the colder months hunkered in the mountainous fir forests of central Mexico, but in the spring travel northward into America and Canada to be near their larvae’s favorite food, the milkweed plant. In the middle of it all are the croplands of the Midwest, where the monarchs engage in a flurry of breeding that sets the direction for future generations to spread over the continent. To keep reading, click here. Continue at source:  Tracking This Year’s Dismally Small Monarch Migration ; ;Related ArticlesMystery Lung Fungus: Are You at Risk?Buried in Muck, Clues to Future NYC DroughtIs Keystone XL a Distraction From More Important Climate Fights? ;

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Tracking This Year’s Dismally Small Monarch Migration