Inbreeding depression, Hamm said, is basically a lack of genetic variation within a population as a result of inbreeding.

“Last year in Michigan, we knew of 17 sites that had this butterfly and two in Indiana, and we’ve lost one in Michigan and one in Indiana,” Hamm said.

Mitchell’s satyr live in prairie fens, a rare type of wetland habitat found in southern Michigan and northern Indiana, Hamm said.

“As these habitats become more rare and isolated … inbreeding depression becomes more likely,” said Doug Landis, Hamm’s adviser and a professor of entomology.

“The largest population is between two and three thousand, and the smallest is in the tens and those sites may be going extinct.”

Hamm said he traveled to the sites in Michigan where populations are known to exist and took samples from the wings of individuals to study their DNA.

“I net the butterfly, I hold it in my left hand; with my right I take a pair of forceps and take the piece I need and then I mark the butterfly so I don’t catch it again,” Hamm said. “It’s a very small butterfly: If it folds its wings in half, it’s about the size of my thumbnail.”

Hamm said the technique does not harm the butterflies at all.

Prairie fen are rare because of the unusual way they were originally formed, Hamm said.

“When the last glaciers covered Michigan about 10,000 years ago, they dug up the bedrock in two places, digging holes in the water table, and ground water (then) fed the grasslands,” he said.

“Because (the water) comes through the bedrock, it has extra nutrients you don’t often find, and plants that are able to live there are very unique.”

The Michigan Department of Natural Resources has made some effort to preserve those sites.

“We have a couple sites in state parks where we know that species exists,” said Glenn Palmgren, ecologist for the Parks and Recreation Division of the Department of Natural Resources.

A few years ago, one such site in southwestern Michigan was becoming overgrown with shrubs, Palmgren said. To make it more hospitable for the Mitchell’s satyr, the DNR cleared out some of the site’s overgrowth, Palmgren said.

Prairie fen habitats are becoming scarcer and farther apart, which causes populations to become more isolated, Landis said.

Hamm said he has spent the last couple of weeks extracting DNA from the samples. If inbreeding depression is found to be the cause, there are steps that can be taken to preserve the species.

“We see at some sites five to 10 butterflies. What we want to do is take some butterflies from the larger populations and take them to the smaller populations to supplement, (to) give them a boost,” Hamm said.