Blue butterfly bonanza in the Superior National Forest
IN THE SUPERIOR NATIONAL FOREST — The Nabokov's blue perched on a dwarf bilberry plant and spread its wings, apparently content to sun itself as cameras clicked close by.
This, those of us watching agreed, is what we came for.
The tiny, bright blue butterfly might be small in stature, but its unique coloration makes up for it in sheer sartorial splendor. And this clearing, about 20 miles north of Two Harbors, is by far the best place in Minnesota to find them.
On a warm day last week, the Nabakov's blues — named after the famous Russian author and butterfly fan — seemed to be everywhere, darting amidst short spruce and tamarack trees before landing on tall grass or a little bilberry.
The short cousin of the blueberry, dwarf bilberry is the only plant upon which the Nabokov's blue will lay its eggs.
"You have to have dwarf bilberry to have blues, and this is a pretty good bilberry spot,'' said Dan Ryan, wildlife biologist for the Laurentian District of the Superior National Forest.
After emerging in early summer, the adult Nabakov's blues — also called northern blues — live only a couple of weeks, enough time to mate and lay the next generation of eggs on bilberry leaves.
"This may be the most I've ever seen. This is a good day," said Wally Mattson, a Duluth butterfly expert.
Mattson and Ryan were among about a dozen Forest Service staff and local volunteers who were here for an annual butterfly count. Now in its 12th year, the count provides a snapshot of the number of species and their general population levels for these little-studied forest butterflies.
But the clearing that was once the rail-side village of McNair holds far more butterfly species than just blues (a species of special concern in Minnesota.) It's only about 15 acres, yet this spot holds the Minnesota record for the most species of butterflies in one place — now up to 70. One species seen here in past years, the grizzled skipper, has never been seen anywhere else in Minnesota.
During any given year's survey, on a single day in early July, counters will tally more than two dozen different species of butterflies here, most of them small and unknown to the untrained eye. The butterfly counters waded through the wildflowers and called out the names of butterflies they could positively confirm.
"Greenish blue,'' one counter yelled, with Mattson keeping score. "'Silvery blue,'' another voice heralded from across the field.
"It's a great reason to get out into the woods. You only do it on nice days. You don't have to be quiet or sneak up on them'' like birdwatching, said Jim Sanders, a volunteer butterfly counter and retired Forest Service official.
The species' names are as impressive as the insects. Dreamy duskywing. Silvery checkerspot. Northern crescent. European skipper. Cabbage white. Clouded sulphur. Northern pearly-eye. Dun skipper. Red admiral.
"The most frequent one we get is 'I don't know what it is,' '' Mattson said with a laugh. But after paging through the Northland butterfly bible — Larry Weber's "Butterflies of the North Woods'' field guide — the counters usually agree on what they saw. Everybody has a camera so they have proof of what they saw.
This year the count hit 26 species, the same as 2014, including two species never before seen at the site — the northern broken-dash and Gorone checkerspot. (Counters say they are seeing more southerly species every year.) The results are forwarded to the North American Butterfly Association.
McNair was once a town site where early 1900s loggers brought their white pines to be shipped south and made into the lumber that built Midwest cities. Parts of a few log buildings can still be seen. But, for the most part, the only thing that remains of McNair is a clearing in the forest.
That clearing has been maintained in recent years by Forest Service efforts, including thinning brush and controlled burning, to hold back aspen and willow from overtaking the area. But crews have to be careful not to burn too much at any one time because they may be burning up the eggs of rare butterflies.
Butterfly enthusiasts have known about this hotspot since the 1960s. In 1986, the Nature Conservancy purchased what had been private land and, in 1991, transferred it to the Forest Service.
Since then the agency — more accustomed to worrying about habitat for moose, wolves or lynx — has been trying to hold back the forest from reclaiming the opening for much-smaller critters.
Farther north near Tofte in Cook County, the Forest Service is starting to work on a site near Plouff Creek that also holds dwarf bilberry and numerous butterfly species.
"It's been going on here (McNair) for years. But, across the region, across the Service, really, there's definitely been more emphasis recently on pollinators,'' Ryan said. "This is the perfect spot to focus some of our attention."
Twelfth annual McNair butterfly count
Superior National Forest
Northern crescent 80
Northern (Nabokov’s) blue 71
European skipper 70
White admiral 21
Northern pearly-eye 10
Clouded sulphur 7
Cabbage white 5
Silvery checkerspot 5
Common ringlet 5
Tawny-edged skipper 4
Canadian tiger swallowtail 4
Dun skipper 3
Silvery blue 3
Dreamy duskywing 2
Hobomok skipper 2
Atlantis fritillary 2
Northern broken-dash 1
Dorcas copper 1
Striped hairstreak 1
Greenish blue 1
Harris’ checkerspot 1
Gorone checkerspot 1
Milbert’s tortoise-shell 1
American painted lady 1
Red admiral 1
Common wood nymph 1