Dune and Swale

In Northwest Indiana, at the southern tip of Lake Michigan, you can find a remarkable ecosystem. Over the last 10,000-20,000 years, the Lake Michigan shoreline has been gradually receding. As the lake recedes, the sand dunes become stabilized by a shifting sequence of vegetative changes known as primary succession. What begins as a sandy community of grasses becomes a wooded ecosystem. The dune ridges remain as gently hills running parallel to the lakeshore. The swales between them remain wet, at least during parts of the year. The dunes and swales are home to a remarkable community of plants and animals.

Today Leon and I visited with John and Jane, longtime friends from the prairie restoration movement; Laurel, a longtime friend from prairie restoration who now works at the Field Museum. Our guide was Paul from the Indiana field office of The Nature Conservancy and steward of the two sites that we toured.

Robin's Plantain (Erigeron pulcehllus) on a wooded dune


Wild Lupine (Lupinus perennis) and Prairie Phlox (Phlox pilosa)

We had come in search of two species: The endangered Karner Blue butterfly, and Yellow Ladyslipper orchids. It was cloudy, and even sprinkled a bit as we arrived. But the plant viewing was so amazing that we didn't mind. Besides, the weather forecast was for clearing around lunchtime.

Yellow Ladyslipper (Cypripedium calceolus)

It didn't take us long to find our first ladyslippers. This is an amazing orchid. It's reasonably large (the pouches are over an inch long. Although a rare plant globally, it's extremely common in the dune and swale ecosystems in Indiana. We saw thousands of blooming plants during our travels today. Some were individaul sprigs. Others small clumps.

A clump of ladyslippers

At times, there were large patches with hundreds of blooms in them.

Part of a huge patch of orchids

As we walked further, we had to traverse numerous swales. It was a day of wet feet (and ticks...but let's not dwell on unpleasantries here).

One of the swales where we got our feet wet

Blue Flag Iris (Iris versicolor)

At last, it the skies began to lighten. No butterfiles initially, but we did start seeing some other insects.

A bird dropping moth in the family Noctuidae

A net-winged beetle (Calopteron reticulatum)

Finally the sun broke through. Would be see Karners? Yes we would- almost immediately once the sun broke out.

Male Karner Blue (Lyciades melissa samuelis) basking

Karener Blue caterpillars feed on leaves of the lupines that are so abundant in the dune and swale ecosystems. It has vanished from over 90% of its range and was declared an endangered species by the fedreal government in 1992.

Male Karner Blue, underside
This one embiggens well

Such satisfaction. Endnagered butterflies. Rare orchids. Other fabulous plants and animals. What more could we possibly have wanted? I was thrilled. I would have gone home happy. I got to get another good look at another very rare butterfly.

Dusted Skipper (Atrytonopsis hianna)

The Dusted Skipper is a very rare species that lives in sandy areas. I am aware of only two populations in Illinois. They are a bit more abundant in northwest Indiana, but still a rare species. These posed for photos.


This was definitely a day to savor. I spent time with friends that I don't see often enough. We visited beautiful, rich and rare habitats and saw and photographed lots of rare plants and animals. Our day ended with pleasant conversation at a nearby Mexican restaurant.