Snapshots
Butterfly valley
November 04, 2013
More than a million Euploea tulliolus koxinga, a genus of milkweed butterflies, are pictured Nov. 3 in Maolin National Scenic Area, southern Taiwan. This winter swarming behavior, referred to by entomologists as purple butterfly valley, is rarely seen and only known to occur for various species in North America, northern Australia, Hong Kong and India. (Courtesy of Maolin National Scenic Area Administration)