Although some of Michigan's endangered wildlife species, such as the bald eagle and gray wolf, have made remarkable comebacks in recent years, not all endangered populations have been so fortunate.

One species that remains in danger of extinction throughout all or most of its range is the Mitchell's satyr butterfly.

This medium-sized, dark brown butterfly, with a distinctive series of orange-rimmed black eyespots on the lower surface of both wings, is known to exist in just 17 sites -- 16 in Michigan and one in northern Indiana.

It lives in fens which are fairly rare, low-nutrient, alkali-soil wetlands, characterized by sedges and wet-meadow grasses, low-land shrubs (such as poison sumac) and tamarack trees. Fens sometimes are associated with streams running through them and sometimes with marl pits. The caterpillars feed on sedges and grasses.

Barb Barton, a biologist with the Michigan Natural Features Inventory, has been studying satyrs since 2003, conducting annual surveys of the butterflies at their known locations and trying to determine if it is possible to expand the creatures' range.

Barton has been conducting a mark-and-recapture study on satyrs in a Jackson County fen, returning every two years to the same location (which she isn't anxious to publicize because of the rarity of the satyrs).

The adult butterflies are caught, marked with a number on a wing with a fine-tipped felt pen and released. The number of times the marked butterflies are recaptured compared to the overall number of specimens captured gives biologists an idea about the size of the population.

But Barton also is trying to determine the size of the home range of the insects and how far they travel to see if additional management of surrounding land will benefit the species.

A prior research project conducted in Berrien County in 1998 showed a home range of about .03 hectare (a hectare is 2.47 acres) for Mitchell's satyrs. Barton has found some males range slightly more than three times that far -- up to .10 hectare.

But whether that is enough to expand the population is very iffy. Fens are so widely isolated from one another that it is doubtful that populations can colonize other habitats, unless suitable habitat is restored or created between the fens.

"Satyrs live in prairie fens and, as far as we know, they don't fly out of those fens very often," Barton said. "If their home ranges are so small, it doesn't do you any good to create habitat because they're probably not going to move into it. But if we know how far they'll travel, we can manage habitats within that range."

Barton said there has been plenty of discussion about reintroduction, "but we still don't have a handle on what they need to survive," she explained. "We know what the fens look like where they live, but there are a lot of habitats that look good that doesn't have any satyrs. And there are really only three or four populations that are big enough for us to consider taking satyrs out of them."

The largest population of Mitchell's satyrs that Barton has found is estimated to be about 3,000 individuals in 2007, but "last year was a boom year," she said. Butterfly populations are cyclical and can vary widely from year to year.

Historically, Mitchell's satyrs were known to exist in about 30 locations in America, including sites in Ohio and New Jersey, but those populations appear to have been extirpated, perhaps by butterfly collectors who have pursued these rare creatures.

In recent years, small populations of satyrs also have been found in Virginia, Mississippi and Alabama. Genetic testing currently is under way at Michigan State University to determine whether these are the same species as the satyrs we have in Michigan.

Mitchell's satyrs are known to exist only in the lower tiers of counties in southern Michigan. They have been found as far north as Barry County, but, in recent years, have been found in only one new location -- Cass County. In 2000, biologists surveyed more than 100 fens across the state looking for the butterflies.

"I wouldn't imagine there are many more sites with them, at least here in Michigan," Barton said.

Mark-and-recapture studies are intensive work, Barton explained, because the adult butterflies are only here for about three weeks, from late June into July. (The longest period between a mark and recapture for Barton was a male satyr that she caught twice, 19 days apart.) The adults emerge from their cocoons, mate, lay eggs and die; only a few adults each year have been observed taking nectar from flowers, which is unusual in the butterfly world.

They also are difficult to handle, Barton said, because they are such fragile creatures. Satyrs are delicate, vulnerable to storms and predation from a number of other creatures, including spiders, dragonflies and praying mantids.

Management efforts, thus far, have centered on preserving the habitats where the butterflies are found through cooperative efforts among private land owners, conservation groups and the DNR.

Land managers are able to set back succession by clearing brush and trees, but are careful to leave species (such as tamaracks) that are important to the character of the habitat. Satyrs are edge creatures, not residents of big open meadows, so it is important to preserve some of the shrubs that they use, too.

As with most studies of unusual creatures, funding often is difficult to obtain and that gives Barton "a sense of urgency" in her work.

"I think they are kind of secure in their larger sites," she said. "But it's the smaller sites I'm worried about."

A plan is being developed to help conserve the butterfly and its habitat in Michigan and Indiana. For information on progress in conserving the Mitchell's satyr, as well as background on its biology and habitat, visit the DNR Web site at www.michigan.gov/dnrnongame.