WASHINGTON - No one ever paid much attention to Mardon Skipper. It's not brightly colored. When it flies, it stays close to the ground. And it does most of its fluttering earlier in the year than other butterflies.

Maybe that's how the small, brownish butterfly ended up as a candidate for the federal list of endangered species.

Mardon Skipper fans, though, received some good news this month: researchers have discovered several new populations of the bug - including one site north of Brookings and another east of Crescent City, Calif..

Because of those finds, the U.S. Fish and Wildlife Service, which decides which plants and animals go on the federal threatened and endangered species list, lowered the skipper's threat level, from 5 to 8, on a scale where 1 means the species is most threatened.

Conservationists stressed that the Mardon Skipper remains a species at risk, in part because people still know very little about it. But finding the new populations was good news, said Scott Hoffman Black, executive director of the Xerces Society, a Portland group that advocates for the protection of invertebrates, including insects.

andquot;We actually petitioned it for Endangered Species Act listing some years ago, because we knew of so few populations,andquot; Hoffman Black said. andquot;I have to say that this is a butterfly that when we did further study on it we found substantial new populations.andquot;

Based on that new information, federal agencies and environmental groups are reassessing what to do about the skipper, right now.

The skipper - that's a term for a low-flying butterfly - rarely leaves the patch of grass where it's born, making it easy to wipe out any single community.

andquot;The butterfly was on the candidate list for a reason - because it was, and still is, very rare,andquot; Hoffman Black said. andquot;If something happens to that meadow then those butterflies are sunk.andquot;

A historical map of the skipper's range showed the sites near Brookings and Crescent City, said Kelli Van Norman, inventory coordinator for the federal Interagency Special Status/Sensitive Species Program in Oregon and Washington. Last summer, though, researchers found a single butterfly at Samuel Boardman State Park, between Brookings and Gold Beach.

andquot;I was like 'Oh my gosh, Gold Beach,'andquot; Van Norman said. andquot;That was quite a bit farther north than we had expected.andquot;

A handful more mardon skippers were found at another meadow on nearby BLM land this year. Both sites are already protected, meaning the butterfly's discovery is unlikely to result in new restrictions on grazing or recreation activities, Hoffman Black said.

In other places, however, the Mardon Skipper is threatened by habitat loss, invasive weeds, pesticides, off-highway vehicle use, grazing, roadside maintenance, and grassland management activities such as prescribed fire and mowing, according to a 2007 report on the butterfly's status by two Bureau of Land Management biologists.

Hoffman Black praised the energetic response by the U.S. Forest Service and Bureau of Land Management. The agencies funded two studies that revealed previously unknown facts about the skippers' range and where they lay eggs.

andquot;The Forest Service and the BLM, they're really engaged,andquot; Hoffman Black said. andquot;A lot of times candidates just languish on the U.S. Fish and Wildlife list.andquot;

A Washington State University graduate student named Loni Beyer added another important piece to the puzzle in a thesis that she presented recently, Van Norman said. Beyer found that the skipper will lay its eggs on several different species of grass, rather than on just a single type, as scientists had suspected.

Despite that new information, though, there's a lot scientists still don't know about the skipper. For example: What purpose does it fill in its ecosystem?

andquot;We don't know, exactly,andquot; Van Norman said. andquot;We would assume that it pollinates.andquot;

Searchers found new skipper sites scattered across the Northwest, generally in meadows between 4,000 feet and 5,000 feet high. But other areas that seemed perfect for the bug were empty.

andquot;Why isn't it on the Umpqua and the Willamette?andquot; Van Norman asked. andquot;We don't know.andquot;