I wrote Sunday about the effort to prevent two Minnesota butterflies, the Dakota skipper and Poweshiek skipperling, from going extinct. Here are a few more images from my visit to the Minnesota Zoo's captive breeding program.

Here's Erik Runquist, the biologist who's running the project, inside the laboratory looking at specimens of a different butterfly, which is being monitored to compare it to the Dakota skipper's life cycle.

Cale Nordmeyer, the zoo's butterfly conservation specialist, examines one of the plastic tubes containing a plug of prairie grass and a hibernating Dakota skipper caterpillar. He's inside the "hoop house" that's adjacent to the seasonal butterfly garden.

The exterior of the hoop house.

A Dakota skipper larva hatching. (photo courtesy of Minnesota Zoo)

What success looks like: The first male Dakota skipper reared at the zoo. (photo courtesy of Minnesota Zoo)