Bog Butterflies

As I mentioned in my previous post about searching for the Chryxus Arctic (May 28, 2017), I’ve always wanted to see some of North America’s “northern” butterflies. A quintessential habitat of the “north country” is the bog. A bog is a water-filled depression with a mat of vegetation floating on its surface. Bogs are acidic, nutrient-poor habitats, with no seepage or run-off—all water is obtained through direct precipitation. Bogs are well-known for a host of fascinating plants, including carnivorous plants such as sundews and pitcher plants, which trap and consume insects to help offset the lack of nutrients.

There are also several butterflies that can only be found in bogs. I recently made two trips to northern Wisconsin to visit bogs to try to see a few of them. The target of the first trip, in late May, was for another satyr, the Red-disked Alpine. Affectionately abbreviated to the acronym “RDA,” the Red-disked Alpine is a beautiful gem—with a wingspan of about two inches, it appears very dark in flight, but flashes dark red on the forewings as it flies by. If it lands, it displays its dark brown coloration, covered with wonderful gray shading and mottling on the outer edges of the wings.

I was told that a great place to find RDAs was in a bog east of Three Lakes, in Forest County. The “advantage” of searching for RDAs in this bog is that there is a snowmobile trail running through the bog. The winter traffic of the snowmobiles removes the characteristic hummocks of the bog making walking comparatively easy. Bogs are notoriously difficult to explore. Depending on the subtle differences of the vegetation forming the floating mat, walking can be either relatively easy or very tough, with many hummocks hiding roots and other woody vegetation. In between the hummocks one may also discover holes in the mat where one’s foot can suddenly sink in up to the thigh. Carrying camera gear, watching your step, and trying to track a butterfly—all at the same time—can be an exhausting experience. Of course, if the butterfly is found, all that exhaustion seems to melt away!

Following the snowmobile trail certainly did make the walking fairly easy, but each step was still followed by a “slurp” of suction as I pulled my foot out of the mat. If I kept walking, it was fairly easy, but whenever I stopped, I slowly sank into the mat, making getting going again difficult. The first butterfly to appear was a Brown Elfin, a species found in bogs and other habitats where blueberries, its larval host, grows. It posed nicely for me. I crouched down to get a better angle, and fired off several shots. As I continued to photograph it, I gradually realized my butt was getting wet. Without realizing it, I was sinking into the mat. The elfin flew off, and it was time for me to move too. The first step was difficult, but I was finally able to lift my boot out of the mat and get underway.

I followed the snowmobile trail back and forth across the bog for about three hours. Finally, as I was about to give up, I flushed an RDA from the trail. It flew past me and I “ran” after it. The action of a short-legged guy with camera gear flung over his shoulder slurp, slurp, slurping after a brown butterfly fortunately was not caught on video. The RDA landed about 50 yards down the trail. Fortunately, it was patient and waited for me to catch up. Out of breath, I finally got to it and fired off a few shots. It flew again, and again I chased it (more slurp, slurp, slurping). This time it landed without vegetation obstructing my view, and it sat for several minutes while I got a long series of photos.

It finally flew again and when it landed it had its forewing pulled up a bit more, revealing the “red disk” of its name (see photo at beginning of this blog). A truly spectacular butterfly!

On my second trip, in early June, I hoped to find Frigga Fritillary and Bog Fritillary, two of the small “lesser fritillaries” of the north. Friggas have a single, short flight period of a few weeks in late spring. They are typically found in somewhat “shrubbier” bogs where willows and birches, their larval hosts, grow. I investigated a bog within Riley Lake State Natural Area, but this time I had no snowmobile trail to assist me. After about 50 yards and half an hour, I realized I was not going to be able to walk for long in this bog. It was very rough going, with shrubs, hummocks, and sinks. I made it back to the road and sat down and guzzled a bottle of Gatorade. I decided I was just going to have to wait for a Frigga to find me in the road. I drove to another spot nearby where willows were growing right along the road, and I simply started walking back and forth down the road, hoping a Frigga would appear. About half an hour later one showed up, but kept moving as it flew past me. About an hour later another appeared, but it kept going too. Finally, after about two hours, and a few more fly-bys, I found a Frigga seeking moisture in the road. Fortunately, it was a cooperative individual, and hung out on the road for several minutes while I got many photos.

The next day I visited Glocke Lake to try to see Bog Fritillary. Bog Fritillary is the third in the seasonal parade of lesser fritillaries to appear in bogs (preceded by Freija Fritillary—which I had seen on the first trip but did not succeed in getting good photos of—and Frigga). Glocke Lake is further south than Riley, so the butterflies were a little further ahead and the Bog Fritillaries had just begun to emerge earlier in the week. Glocke Lake is surrounded by a classic sphagnum mat bog—quite easy to walk on, with that classic floating, “quaking,” feeling as you slurp along. The bog is graced by a wonderful array of plants—from Labrador Tea, which provides some nectar for the fritillaries, to pitcher plants and orchids.

As the day warmed up and more sunlight reached the bog, Bog Fritillaries began to appear in large numbers. They were joined by another lesser fritillary, the Silver-bordered Fritillary, which is more of a generalist species, occurring not only in some bog habitats but also other wetlands and even dry habitats, such as prairies. These two fritillaries are very similar on their upper surface, but the ventral surfaces are quite different, making identification easy once they close their wings.

Despite the difficulties of moving around and exploring bogs, it was fun to see and photograph a few species new to me, in a habitat I hadn’t explored for many years!