Butterfly observers in Illinois are seeing a phenomenon this year that is playing out nationally: As the monarch starts its near-3,000-mile winter migration from Canada to Mexico, their observed numbers were extremely low.
Chicago Academy of Sciences chief curator Doug Taron says the monarch is "the second or third most common species" of butterfly that observers record, but this year, it's the "seventh."
Taron says this summer has been "pretty dismal" for butterflies in Illinois. Observers typically record 85 species a year, but reports show 68 this summer.
Monarch Joint Venture co-chair Karen Oberhauser says the monarchs' difficult summer began March 9 in forested mountains near Mexico City, where tens of millions overwinter. A storm struck the area, killing large numbers of the butterflies and inflicting heavy habitat damage.
