I am Sibylla Brown. I was born in Germany in 1940. In 1946 my father, a German Operation Overcast scientist, was brought to the U.S. My family followed him to the U.S. in 1947, settling in Cedar Rapids Iowa in 1950. I married my husband, Bill in 1962. Bill practiced dentistry in Des Moines for over 40 years. In 1993 we sold our house in Des Moines and moved to a 200 acre farm in Decatur County, Iowa. Except for a small vineyard we had no plans to farm our land. But we did want to take care of it, particularly the overgrown oak and hickory woodlands. We began timber stand improvement in 1993. When we learned our land was actually a rare oak savanna remnant we implemented prescribed fire. I keep monthly journals to record our activities and observations. These posts summarize them.
“That thing the nature of which is totally unknown to you is usually what you need to find, and finding it is a matter of getting lost.”
I’ve been reading Rebecca Solnit’s marvelous collection of essays, A Field Guide to Getting Lost. The above quote is from the first essay, “Open Door”. (attributed to pre-Socratic philosopher Meno). It describes exactly where I was in April – completely lost trying to identify moths that came to baited trees. Determined as I am to collect and identify as many Timberhill butterflies and moths (Lepidoptera) as possible I knew that I would soon be lost. I can usually find my way among the silk moths, underwings, flower moths, and stem borers but am blinded among Pinions, Sallows, Cloverworms, Quakers, etc. What makes it all the more difficult is the variation among specimens of the same species. These two photos of the common Speckled green fruit worm moth illustrate the difficulty. I downloaded six photos of this species before I realized they were all the same species.
Moths seen and identified in April: Elaphria grata, Grateful midget, Eupsilia vinulenta, Straight-toothed sallow, Hypena scabra, Green clover worm moth, Lithophane atennata, Ashen pinion, Lithophane bethunei, Bethune’s pinion, Melanolophia canadaria, Canadian melanolophia, Mythimna unipuncta, Armyworm, Orthosia hibisci, Speckled green fruit worm moth, Zale gbalbanata, Maple sale, Sphecodina abbottii, Abbot’s sphinx, Drepana arcuata, Arched hooktip, Pero ancetaria, Huber’s Pero.
We saw the first spring azures on wing April 3 when the thermometer topped out at 83’ F. A black swallowtail was sighted the next day. On April 11 we saw the first Juvenal’s duskywing, a small black skipper. Interestingly the moth baited trees attracted an abundance of Red Admirals and only one Comma butterfly on April 13. This was just the opposite of what we observed on March 23 when we saw nineteen commas and only one Red Admiral. The first Meadow fritillary sightings were on April 19: one in the restored meadow and one puddling in the creek.
April Butterflies: American lady, Black swallowtail, Eastern and Gray commas, Juvenal’s duskywing, Meadow fritillary, Mourning cloak, Orange sulphur, Pearl crescent, Red Admiral, Red-spotted purple, Spring Azure.
I’ve never seen the spring ephemerals as spectacular as they are this year. Bluebells fill the lower portion of every hillslope, thousands of wild hyacinth are blooming in the east savanna, and bloodroot has moved uphill to the East Savanna ridge top. Of particular note is the abundance of Sandwort, Moehringia (Arenaria) lateriflora. In 2004 I found a small population in the prairie opening below the Hickory Grove. This year it covers one third of the prairie with its small white blossoms. Sandwort has a strong affinity to high quality oak-hickory woodlands and prairie openings (COC=10). We’re very pleased to find it so abundant here.
As usual the morels didn’t behave as expected. The warm weather in early April should have stimulated fruiting by the second week. But we lacked adequate precipitation – only .49 inches rain until April 18 when we had .32 inches. That was enough to get things going and we found our first specimen in Hickory Grove on April 19. In Iowa morels one usually looks for morels around dying and dead elm and cottonwood trees. But in the Hickory Grove they are associated with scrub shingle oak and mayapples. So far fruiting has been very scattered. Of the four Timberhill morel habitats we have found morels in only two. We had plenty of rain the week of April 24 (1.5 inches) but the temperature dropped into the 40’s each night and stayed in the 50’s during the day and fruiting ceased. It will be interesting to see what develops the first week of May when warm, sunny days are predicted.
Unusually warm weather in December through February extended into March with temperatures averaging 6 degrees above normal. Spring got off to an early start. On March 11 I saw the first Spring Azure butterflies on wing. Last fall butterfly-moth bait that we had painted on shagbark hickories in the Hickory Grove attracted multitudes of Eastern Comma butterflies. Curious to learn if they had overwintered under the hickory bark we baited these trees again. Beginning March 14 the Commas and an occasional Red Admiral were attracted to the bait whenever the temperature climbed above 50’F. On March 23 I counted 19 Commas on baited trees.
The spring ephemerals also put on an early show. Bloodroot began blooming on the east facing hillsides above Brush Creek on March 15. On March 17 Midland Fawn Lily, Erythronium mesochoreum, was blooming in sunlit spots on the south facing Hickory Grove trail. The bloom quickly spread into the Timberhill open woodlands and oak openings. With it’s narrow, conduplicate (folded lengthwise), blue-green leaves this species is easily distinguished from the White Trout Lily, Erythronium albidum. The latter has wider mottled, flat leaves, and blooms later. I did not see any White Trout Lily leaves until March 31. (As of that date it had not bloomed at Timberhill.) The two plants can also be distinguished by the mature fruits: E. mesochoreum fruits rest on the ground while E. albidum fruits are usually held erect.
According to Robert B. Kaul’s paper “The Status of Erythronium albidum and E. mesochoreum” the distribution of the latter is much smaller than E. albidum. It is restricted to “virgin tall-grass prairies and occasionally in woodlands.” Steyermark describes E. mesochoreum habitat as “glades, prairies, or dry open woods” whereas E. albidum is found in “low, moist woods, along streams, valleys, on slopes and wooded bluffs.” At Timberhill we found E. mesochoreum in the open woodlands, native prairies, and oak openings.
Also blooming in March were Spring Beauty, Rue Anemone, Dutchman’s Britches, Toothwort, and False Rue Anemone. With the warm weather I had hoped to find the first morels which have fruited here as early as March 27. No such luck. We’ll have to wait for April.
A small flock of wild turkeys took advantage of the burned prairie and woodland north of the pond. The lack of cover made it easier for them to find acorns and hickory nuts to feed on. (It was too early in the year for grasshoppers, their favorite food.) Great blue herons returned to the pond the first week in March. They nest in cottonwoods along the Weldon River to the south and are frequently observed feeding in our well-stocked pond.
For twenty years I’ve been keeping a record of what I call the signs of spring. I began collecting this data in anticipation of morel season in order to determine when it was time to begin looking for morel mushrooms. “Signs of Spring” is my record of the date of first spring mushroom begins to fruit, when each spring ephemeral on the list begins to bloom, and what I consider important spring events. (Over the years I have learned that the best morel indicator is the asparagus patch in my vegetable garden. Morels always fruit within a week of the first asparagus spear.)
Crimson cup mushrooms are usually the first mushrooms to fruit each year. At Timberhill I often see them on warm January days. They fruit on fallen basswood branches along Brush Creek east of the house. This year they were particularly abundant in February. Last month was still too early for any spring ephemeral bloom, but spring beauty, violet, and nettle leaves had sprouted.
An important event on my list is the return of the red winged blackbirds. They are always the first migratory birds to return each year. I saw the first specimens settling into the cattails on the pond’s edge on February 20. That’s three weeks earlier than usual.
This year I added a new event to my list: the first butterfly sighting. On February 20, an unusually warm, sunny day when our weather station thermometer registered 65’ F. by mid-afternoon, a comma butterfly flew by me when I was taking my daily walk. (It was so unexpected and flew by so quickly that I didn’t see whether it was a gray or an eastern comma.) According to Butterflies of Iowa overwintering commas usually begin flying in mid-April. February 20 is very early. Does that foretell an early spring? One can only hope.
Winter arrived here three days after Christmas when we had our first winter storm – five inches of snow alternating with freezing rain and sleet. My favorite activity on such winter days is to curl up in front of the wood stove with a good book. Last month it was Andrea Wulf’s The Invention of Nature, a Christmas present from my son Chris. This biography of Alexander von Humboldt explores how the visionary German naturalist created modern environmentalism. His writings inspired many not only Charles Darwin, but Henry David Thoreau and John Muir.
Many believe that climate change is a twentieth and twenty-first century problem. But as Alexander von Humboldt observed climate change began much earlier. It is based on the human presumption that nature was created to serve man. From Aristotle who believed that “nature has made all things specifically for the sake of man” to the Cartesian belief that it is man’s responsibility to bring order out of chaos, we have “improved” on nature by plowing the soil, by straightening our streams and rivers, and destroying our woodlands.
Humboldt formed his most important concepts during his five-year journeys (1799-1804) through South America. At that time many scientists held the narrow view that one could understand nature by collecting and classifying. Based on observations he made in natural settings Humboldt realized that one can only fully understand nature by comprehending how everything was connected. Around Lake Valencia in Venezuela, for example, he observed how clearing the forests and diverting water to irrigate their fields the planters had caused the lake’s water level to fall precipitously. Their agricultural practices were also depleting soil fertility and destroying the soil’s ability to retain water.
“When forests are destroyed, as they are everywhere in America by the european planters, with an imprudent precipitation, the springs are entirely dried up, or become less abundant. The beds of the rivers, remaining dry during a part of the year, are converted into torrents, whenever great rains fall on the heights. The sward and moss disappearing with the brush-wood from the sides of the mountains, the waters falling in rain are no longer impeded in their course: and instead of slowly augmenting the level of the rivers by progressive filtrations, they furrow during heavy showers the sides of the hills, bear down the loosened soil, and form those sudden inundations that devastate the country.” Wulf, p. 57-58. Humboldt, p. 150-151
At Timberhill we have learned that these changes are not irreversible. When we purchased West Creek in 2004 the banks of creek that separates this unit from the rest of our property were eroding and the creek was cutting deeper and wider. Since only the ridge tops and a bottom field had been plowed and there had been some grazing the land still contained remnant prairie and wetland. The biggest problem was the red cedar, shingle oak, and honey locust trees that had invaded in the prairies. We began restoration by burning the property three years in a row. That helped control much of the underbrush and made it easier to thin the invasive trees. In 2008 Shelterwood Forestry girdled the honey locusts and began felling the shingle oaks and red cedars. (We kept the elms because they would bring morels.) Bill and I burned the red cedar carcasses in midsummer when they were fully dried out and surrounded by green grasses.
Although Humboldt included the destruction of the forests as one of the the reasons for river flooding it was actually destruction of the native habitat. We removed the trees in this unit because West Creek was originally all prairie. Restoring the prairie vegetation restored the hydrology and curbed the erosion.
Each year as the grasses and sedges increased in the restored prairies we noticed a decrease in stream erosion. To our surprise the creek was actually decreasing in width.
The photo above shows the creek upstream of our property.
Here you can see the creek below our restored prairie. It is half as wide here as it is upstream.
Andrea Wulf, 2015. The Invention of Nature. New York. Knopf
Alexander Von Humboldt (translated by Jason Wilson). 1995. Personal Narrative of a Journey to the Equinoctial Regions of the New Continent. New York. Penguin Classics.
Despite the mild fall and winter weather so far this season we have not been able to do as many prescribed burns as we would like. In order to reduce the impact on the invertebrates we always burn during the dormant season after the first hard frost. That is usually between mid-November and March 15. However, hard frost was late this year, not until November 21. After that it was either too windy or too wet every weekend that our volunteer burn crew was available. Thankfully, a professional crew offered to help. On December 11, my husband, Bill, and the crew burned our West Creek unit.
We purchased West Creek in 2004. At that time it consisted of two crop fields, a small wetland, degraded native prairie, and a sedge meadow. There were also several seeps where water is discharged from underground sand veins. This unit is separated from the rest of Timberhill by a small, sandy creek. The creek provides an excellent firebreak to the east and as does the wide trail through the woodland along our south fenceline. Mowed strips separate West Creek from a cornfield on the west. A small remnant prairie is in the ravine that intersects the cornfield. We also mow a break along our north property line. Keeping the fire from spreading into adjacent prairie remnants north and west of our land can be challenging on a windy day. So we need an experienced crew.
When we purchased West Creek there was no difference between our prairie remnant and the neighbor’s. In the above photograph Timberhill is on the left and the unmanaged remnant begins at the tree line on the right. As you can see red cedar now dominates the unmanaged remnant. The native plants are gradually disappearing. In 2004 I counted nine butterfly milkweed plants there. In 2015 I could only find one. In 2004 I counted two blooming butterfly milkweeds in West Creek. Now there are over thirty, including some in the old cornfield.
Our goal is to restore West Creek diversity – by increasing floristic quality in the prairies, expanding the prairie cordgrass and tussock sedge wetland, and improving groundwater availability. Management has been limited to annual prescribed fires, invasive tree removal, and seeding the old fields with warm season grass collected in the remnants. In nature everything is connected. Fire has stimulated the grasses, sedges, and wildflowers. Infrequent and rare butterflies that require a specific conditions now inhabit the property. We regularly see Dion skippers in the restored sedge meadow. In June and early July Edwards’ hairstreaks nectar on the butterfly milkweed and dogbane in shingle oak scrub above the sedge meadow. Regal fritillaries are also a common site in June and July.
Dion skippers are usually found in northern Iowa. When he saw my specimen a butterfly expert told me, “I would never have expected to find that here.” (This species is restricted to wetlands with broad-leaved sedges.) In Iowa Edwards’ hairstreak is considered rare and very local. Regal fritillaries are infrequently found in wet prairie remnants. The larvae overwinter in leaf duff. Finding these species in West Creek is a strong indication that infrequent and rare butterflies survive our frequent annual burns.