April – August 2008

On a cool “partly cloudy” April day Stewart Wechsler, Paul Doan, Al Wagar, and I headed for Johnson’s Prairie. We met at 8:00 am at Krispy Kremes donut shop located at the Tacoma Mall. The April 18th morning looked promising with patches of blue sky, as we traveled south on I-5 toward Fort Lewis.

Johnson’s Prairie is well known for its biodiversity of flora and fauna and its immense beauty. It is easily approached from Lacy or Yelm, and it is the most remote prairie of the Fort Lewis complex.

We met Cheryl Fimble of the Nature Conservancy at 9:00 to begin our orientation and plan our day.

Fort Lewis has been very supportive to environmental groups and researchers who are looking out for the welfare of endangered or threatened species. Our hats are off to dedicated personnel of the Nature Conservancy, who spend endless hours in maintaining the legacy of the Puget Prairies.

As we began our survey the weather began to deteriorate, and as the morning progressed a chill and heavy overcast persisted. Not a butterfly was seen that day, but with the help of Stewart, we were all given on the spot training and in some cases a review of the native plants of the prairie. We focused on the larval food plants and possible nectar sources that the species of the Puget Prairies would utilize. This would help us a great deal when follow-up visits of the prairie occurred.

May 16th was our second visit to the prairie. Stewart Wechsler and I reached the prairie shortly after 9:00 am. We were greeted with a beautiful morning, clear skies, and with temperatures in the mid to upper 70s. The prairie was divided into five sections, which we systematically surveyed, moving from a north to south direction, studying one section at a time. A map provided by the Nature Conservancy was used to plot numbers of the species seen at the locations encountered. A number was assigned to a species observed, and that number was placed at the appropriate spot on the map (example- # 1 was the Echo Blue). We found butterflies throughout the day, the meadows coming into full bloom. It was truly a beautiful sight to behold as we walked through the prairie. The May survey yielded ten species with the Silvery Blue and Common Ringlet observed most frequently.

MAY SPECIES OBSERVED

• Celestrina echo echo (Echo Blue)
• Glaucopsyche lygdamus columbia (Silvery Blue)
• Pieris marginalis marginalis (Margined White) Pieris rapae (Cabbage White)
• Papilio zelicaon zelicaon (Anise Swallowtail)
• Callophrys polios obscura (Hoary Elfin)
• Callophrys augustinus iroides (Brown Elfin)
• Phycioides mylitta mylitta (Mylitta Crescent)
• Pyrgus ruralis ruralis (Two-banded Skipper)
• Coenonympha tullia eunomia (Common Ringlet)

We were very disappointed in not seeing any Mardon Skippers or Taylor’s Checkerspots, two species being carefully monitored by the Nature Conservancy and Fort Lewis naturalists. The larval food plants and nectar sources were abundant on the prairie, adding to the mystery why these two species are so restricted in distribution.

The June survey occurred on Thursday the 26th. The weather was very favorable with the temperature ranging in the low to mid-70s. The sky was partly cloudy and the prairie was blanketed with numerous wildflowers in full bloom. We used the same mapping technique of the past months to complete our study. Cheryl, Michael, and Laurel Fimble joined me on this absolutely beautiful day. Many new plants were in bloom now, and the early bloomers were waning. The exciting news was that the Puget Blue (one of the target species of the Nature Conservancy) was in abundance. Large patches of lupine (the larval food plant) were distributed throughout the prairie, and we had 122 sightings of the Puget Blue flying close to these plants. The blues seem to be at their peak at this time. Also extremely abundant was the Common ringlet, with 188 individuals observed during the day. The Silvery blue was the third species observed, but their numbers were low now, and all were worn females.

JUNE SPECIES OBSERVED

• Plebejus icarioides blackmorei (Puget or Boisduval’s Blue)
• Glaucopsyche lygdamus columbia) (Silvery Blue)
• Coenonympha tullia eunomia ( Common Ringlet)

On Wednesday, July 16th Cheryl Fimble, Michael Fimble and I conducted our fourth survey. Marine air greeted us as we entered the prairie, but the skies soon cleared revealing a beautiful day with temperatures in the low to mid 70s. Many of the plants in full bloom a month earlier were out of bloom now, but many other species were now coming into bloom, such as the Ox-eyed Daisies and Asters, that blanketed the prairie with white and lavender colors. Grasses were still the dominant vegetation, but now out of bloom. Along the prairie fringes Tansy, Dogbane, and St John’s Wort were abundant. Six species were observed during the day, with the Common Ringlet once again being the most common butterfly. The Puget Blues were now past their prime, but were still seen in fair numbers. Male Great Spangled Fritillaries graced the prairie adding more beauty to the July prairie.

JULY SPECIES OBSERVED

• Papilio zelicaon zelicaon (Anise Swallowtail)
• Colias eurytheme (Orange Sulphur)
• Plebejus icarioides blackmori (Puget Blue)
• Argynnis cybele pugetensis (Great Spangled Fritillary)
• Cercyonis pegala ariane (Common Woodnymph)
• Coenonympha tullia eunomia (Common Ringlet)

The last survey of the butterfly season was conducted on August 28th. Stewart Wechsler, Al Wagar and Ian Young joined me on a cool, partly cloudy day. We formed our parallel lines of north south movement through each section of the prairie, marking each sighting on the map provided. Butterflies had to be flushed with our nets, for the cool air kept them down near the ground. The prairie was taking on a much dryer look since many of the flowering plants were now out of bloom. The only color was seen in the low damper areas of the prairie. Two species of satyrids were the most abundant: Common Ringlet and the Common Woodnymph. In one area the woodnymphs were so abundant it was difficult to count them. In addition to these two species, the Woodland Skipper, and Great Spangled Fritillaries (females only) were identified.

AUGUST SPECIES OBSERVED

• Coenonympha tullia eunomia (Common Ringlet)
• Cercyonis pegala ariane (Common Woodnymph)
• Argynnis Cybele pegetensis (Great Spangled Fritillary)
• Ochlodes sylvanoides sylvanoides (Woodland Skipper)

The transformation of Johnson’s Prairie from April to the end of August was spectacular and very educational. With each species of flowering plants reaching their peak blooming period at different times, the prairie took on a magical new look every month. We were able to observe many plants passing through their yearly ritual of growth and development throughout the season. Each species of butterfly reached its peak flight time during different months as well, with the exception of the Common Ringlet that had many individuals on the wing all through the entire study period.

Those interested in visiting Johnson’s Prairie, might choose June as the time you pick to walk through one of the most beautiful of our Puget prairies. Since Fort Lewis keeps a close watch on these areas, it is highly recommended that one obtain permission before visiting the area. Many research projects are currently being conducted on the prairie, including mammals and birds, thus visitors are closely monitored.

Johnson Prairie Survey

G’num2009Vol10No2