A native butterfly that once roamed Minnesota's prairies hasn't been spotted for about five years and may be facing extinction, the Pioneer Press reports.
In an effort to save the Poweshiek Skipperling, biologists at the Minnesota Zoo launched a breeding program that originates from 20 larvae inside a zoo freezer.
Experts say they're not sure what led to the sudden decline of the Poweshiek, but it's troubling for the prairie ecosystem that's been significantly reduced.
Tall-grass prairie once covered 18 million acres of Minnesota, about a third of the state. Now, less than one percent of the native prairie remains.
According to U.S. Fish and Wildlife Service, the butterfly is a candidate for listing as threatened or endangered.