The Western Forest-Prairie Division

Located to the West of the Grand Prairie Division in Illinois, along the Illinois River valley, our 5th division, the Western Forest-Prairie Division, encompasses much of Mercer, Warren, Knox, Fulton, Peoria, McDonough, Schuyler, Brown, Adams, Morgan, Scott, Macoupin, Greene, Jersey, and Hancock Counties as well as parts of Henderson, Rock Island, Pike, Cass Counties (map).

Here the landscape consists of level to rolling uplands interspersed with deeply cut rivers and ravines with well-developed floodplains. It is a land of deep, forested ravines with intervening flat prairie openings. The area was covered by Illinoian age glaciers. Bedrock outcroppings are common in some locations. This division has two sections—Galesburg and Carlinville—separated by the Illinois River valley.

The Galesburg Section is north of the Illinois River valley; both the Spoon and La Moine rivers drain this area. The amount of prairie here once almost equaled the amount of forest. One interesting habitat type is the dry-mesic barren, also known as an oak opening. In the spring at Argyle Hollow Barrens Nature Preserve look for the very unusual bi-colored bird’s foot violets growing among the mounds of lichens and mosses.

The Carlinville Section is southeast of the Illinois River valley. Macoupin Creek and the Illinois River are the major streams that drain this section. The original vegetation of this section was forest, with only 12% of the area in prairie. Very little prairie or forest remains today in this section.

To experience this area, visit Siloam Springs and Arglye Lake State Parks.

The Grand Prairie

This week we look at the fourth natural division, the Grand Prairie Division. This area encompasses much of Illinois, from as far north as Ogle County, south to Shelby County, west to Henry County and east to the Indiana border (map).

This area, the largest natural division of the state, is a vast plain formerly occupied by tall-grass prairie. The grassland landscape was so unusual that early travelers had to turn to the sea for analogies, evoking “a sea of grass” or “a vast ocean of meadow-land.” In time this landscape came to be known as “prairie.” The fertile soils are young and high in organic content. They were developed from deposited loess, lakebed sediments, and glacial drift. Natural drainage was poor resulting in many marshes and prairie potholes. The prairies were a veritable wildflower garden containing several hundred species of grasses and forbs.

Forests interrupted the landscape on floodplains, on slopes bordering streams, along river bends, and in isolated prairie groves. Like their prairie counterparts, prairie groves have a remarkable number of plant species, especially spring-blooming herbs.In addition to the more common moist forest and prairie communities, dolomite, loess hill, and shrub prairies are found here, as well as barrens, sandstone cliffs, eroding bluffs, sand savannas, and sand ponds. This division has five sections— Grand Prairie, Springfield, Western, Green River Lowland and Kankakee Sand Area.

While much of the prairie has been lost, there are remnants and restorations including Goose Lake Prairie State Park, Midewin National Tallgrass Prairie, Allerton Park, and Kennekuk Cove County Park. Spitler Woods State Natural Area shows a prairie grove habitat and is one of the largest stands of old growth woods in Central Illinois.

Dragonflies

By Susan Post

Illinois has 98 species of dragonflies, all of which are descendants of a prehistoric group at least 250 million years old that included some of the largest insects that ever lived. If any of your summer’s wanderings take you near water, take a few minutes to enjoy the iridescent dragonflies.

Dragonflies begin their life in the water as a dull colored, predatory larvae, called a naiad. They are equipped with large, chewing mouthparts with a lower lip that rapidly extends to capture and hold their prey. A meal is made of any unfortunate small crustacean, minnow, tadpole, or other insect larvae that gets in its path. They are able to search the water for prey by expelling water through gills at the end of their abdomen, somewhat like a hydraulic cannon or a jet engine.

After one or more years of aquatic life, if the larvae have been able to avoid the attention of fish, their chief predators, they will climb out of the water and metamorphose into an adult. Supporting two pair of rigid, transparent wings, which are held outstretched even at rest, and a thick body, dragonflies do not give any outward appearance of grace on the wing. But can they fly! Some species have been clocked at 60 miles per hour as they fly forward, backward, or sideways.

Their eyes are the largest in the insect world, providing the dragonflies excellent eyesight. They can observe insect prey up to forty yards away. Their forward thrust legs are located in a cluster near the front of the thorax and are arranged in a basketlike way to catch prey and quickly transfer it to the mouth. Dragonflies are so well-adapted as airborne predators that their legs are nearly useless for walking.

Their fierce appearance has granted them all sorts of nasty abilities and names. The unenlightened once thought dragonflies were capable of sewing shut the mouths of men who cursed and women who scolded, or they sewed up the ears of people who enjoyed gossip. From these myths a variety of names sprung up such as—snake doctors, horse stingers, sewing needles, and the Devil's darning needle. The myths and names are in reference to the distinctive shape of their abdomen and the mistaken belief that dragonflies are capable of inflicting stings and were harmful to humans. The only harm these insects do is to mosquitoes, gnats and flies, some of their favorite food items, thus earning them the well-deserved name of mosquito hawk.

Green Tiger Beetle

by Susan Post

Walks along sunny paths in late spring woodlands are likely to yield a harvest of jewels. No, these cannot be collected and mounted in a ring; rather, they are emerald green tiger beetles, small but fierce denizens of the forest.

With the sun shining off its irisdescent blue-green elytra, the green tiger beetle resembles an emerald lost on a sandy path. A closer inspection usually reveals nothing—the "emerald" has flown several feet down the path.

Green tiger beetle adults are slender predatory beetles with long legs, large eyes, and thread-like antennae. Like all chewing insects they have a pair of mandibles. The tiger beetle's mandibles are sickle-shaped and very sharp pointed, with several teeth on the inner face. The name tiger beetle refers to its predaceous habits (both adults and larvae eat all kinds of insects) and to the ability of the adults to suddenly pounce on their prey.

During the summer months females will deposit their eggs in sandy soil. The eggs are deposited singly, each in a separate burrow. The larvae are whitish, S-shaped and grub-like with long curving jaws and a large hard head. The larvae prop themselves up in vertical burrows with their oddly shaped heads often plugging the entrance. They wait with open mandibles for a hapless victim, which they seize and take to the bottom of the burrow (sometimes a foot below the surface) to devour at their leisure. On the larva's 5th abdominal segment is a spine that anchors it to the side of the burrow. Thus, if a larva grabs an insect that is too large to overcome, it is anchored to the burrow and will not be pulled out.

The tiger beetle has 3 larval instars, that is, it sheds its exoskeleton three times in order to grow larger. Unlike most insects that just molt and go about their business, prior to each molt the tiger beetle larva must undertake an extra step and enlarge its burrow to accommodate its soon-to-be bulkier self. Pupation takes place in a chamber dug off the main tunnel and the entire life cycle will take up to 3 years.

For those lucky enough to catch one of these iridescent emeralds of the woods, be careful with this jewel of the beetle world for it is not merely ornamental. Tiger beetle mandibles, lethal to most small creatures, can inflict a very effective bite on unsuspecting fingers!

Why Natural Areas? Why Take Pictures? Why do we Care?

by Michael Jeffords
As I drive south for more than 3 hours to give a talk at Southern Illinois University for an unknown audience, assuming one shows up, I think of my spouse’s comment as I left the house. “Why are you doing this?” she said. “I thought you were going to learn to say no!” This leads to a little soul-searching (very little actually) as to what propels me to give the seemingly endless array of presentations that I do, some 1200 over the last 25 years.

The answer is quite simple really. I like it! Also, it is my way of trying to change the world, at least a little corner of it. Whatever skill I may have acquired as a photographer over the years, as well as the thousands of images I have accumulated, mostly of wild places in Illinois, must be put to some use. Now I could attempt to make a living selling images for the marketplace, but I would likely starve pursuing that avenue. I choose to use photography as a tool for education. Fortunately, I have a “day job” that allows me to do this on a regular basis—thus, my jaunt to southern Illinois.

Most of the presentations I make revolve around the central theme of “biodiversity,” the great array of life that covers our planet, and the focus is, inevitably, Illinois. People seem to want to know about 'natural Illinois.' I have found that my niche in all of this may be to recreate that intimate contact with nature that is missing from most individuals’ lives in today’s world. There is, there must be, more to life than malls, minivans, and movie theaters if we are to preserve a significant portion of the life that exists around us.

It is thought that humans have an innate urge to affiliate with other forms of life; this theory, termed “biophilia,” is eloquently described by prominent Harvard biologist E. O. Wilson. The hypothesis also states that biophilia is only partly genetic and must be nurtured from a relatively early age if it is to manifest itself in an individual. I view my role as a “biophilia facilitator” via the medium of photography. I have long since given up on the concept that humans will preserve the earth’s biodiversity based solely on its potential economic value to us. Exploitation wins out over conservation in virtually every instance. If we preserve biodiversity, we are not likely to do it for any direct benefit it may provide to us, but because we choose to, and because we like being surrounded by an endless multitude of fascinating places and organisms.

Ideally, we could take all skeptical individuals into the world’s great natural habitats—the Amazonian rainforest, the African veldt, the Great Barrier Reef— and let them experience their biodiversity firsthand. While this is sometimes possible, it is far more feasible to present images of the natural world to them in a context that says, “These organisms, these places are wonderful and are worth preserving for their own sake.” If these sites happen to be in their own region, their own state, even their own backyard, then the message becomes powerful and provides a first line for nurturing biophilia. It is my experience that the visual elegance of the natural world, no matter where it may be found, is its own best friend and can sell itself if it is given the chance.

As I look back over the last 30 years, I know why I seldom say no to groups who want talks on biodiversity. If they seek knowledge and awareness of the natural world, the least I can do is attempt to provide it. I also believe that the natural areas of the earth, of the U.S., of Illinois, and their organisms deserve to be portrayed in as favorable a light as possible. It ultimately falls on the presenter—in this case, me—to be (sorry, U.S. Army) “all that I can be” with regard to photography. It also falls on us, the citizens of Illinois, when given the opportunity for preservation over exploitation, to choose the former, each and every time.

Every program, each visit to a natural area, the individual "grains of biodiversity" encountered, might add that pivotal sand grain to a person’s psyche that tips the balance in favor of preservation, and that can only be good. Person by person, sand grain by sand grain, we just might make a difference.

Spring Ephemerals

Spring Ephemerals

Puddle Clubs

by Susan Post

Now that spring has arrived, butterflies are starting to appear in numbers, newly-emerged from hidden chrysalids where most spent the winter. A walk along a sunny path or deserted road through the woods, or along the margin of a lake, pond or stream, may yield a unique opportunity for viewing butterfly puddle-clubbing behavior, the proverbial "boys day out at the old watering hole." Puddle-clubbing is a gathering of bachelor male butterflies, usually of the same species, at a moist spot on the ground. Their bachelor status is confirmed by the absence of tell-tail flight marks on their wings such as scratches or faded color.

For most of us, an encounter with a puddle club occurs only when we are suddenly in the center of a cloud of butterflies, having clumsily walked through the gathering. At times though, usually when the gathering consists of a large showy species, such as the tiger swallowtail, we see the club in time and can observe from a distance. In Illinois, a puddle club may consist of only a few males, or as many as a few dozen. Tropical puddle clubs, however, often consist of several hundred males. A patient watcher often sees the reason for puddle-clubbing.

When an appropriate butterfly, usually of the right size and shape, flies near the gathering, males will swarm to meet the newcomer, hoping it to be a female of the same species. If such is the case, several males may initiate courtship behavior; it is then up to the female to choose her favorite. The other suitors may continue to pursue for a time, but most will soon return to await another opportunity. If it should be only another male or another species, the group will quickly settle down again.

Why do butterflies, from the largest swallowtails to the smallest blues or coppers behave this way? No one knows for sure, but entomologists believe that by gathering together, the club creates "a super male", one that is much more likely to attract the fancy of a passing female.

Photos by Michael Jeffords