Thursday, September 29, 2016

Ancient oaks a living link to Big Grove

Ancient oaks a living link to Big Grove

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When people think about the landscape of central Illinois prior to European settlement they tend to think “prairie,” vast expanses of flat land covered in tall grass and tall flowers. And for the most part, that image is pretty accurate.

But groves of trees intruded on the grasslands here and there, especially on the eastern edges of rivers and streams, which created natural breaks to prairie fires driven by winds from the west.

Such groves were dominated by fire-resistant species of oak, and interspersed with hickory, ash, walnut, sugar maple and linden trees as well. 

[Photo by L. Brody Dunn. The bicentennial oak on the lot of the Quaker Meetinghouse in Urbana, IL.]

Prairie groves were quite hospitable to humans compared to the prairie itself, offering game and shelter, as well as respite from some of the discomforts of life in the open. They were preferred sites for American Indian villages, and the first places to be settled by Americans of European descent coming from the east.

One of the largest of these timbered areas in our region was named by settlers of the early nineteenth century the Big Grove.

As it was mapped in the original survey of the area in 1821, the Big Grove covered about 10 square miles. Its western edge roughly paralleled the Saline Branch, the stream that drops into Urbana from the north and runs through Busey Woods and Crystal Lake Park before turning east toward St. Joseph. Along its southern edge the Big Grove extended to about where Urbana’s Main Street runs today.

If you’re familiar with Urbana and the locales just north and east of the City, you know there’s no forest left that would merit the name, “Big Grove,” most of the wood from those trees having gone into houses, fences, farm implements and fires long ago.

But here’s something really cool. Some trees that began life in the Big Grove still stand today. You can touch them. Heck, you can hug them. They’re the kind of trees that elicit that response from people.

Near the corner of East Main and Maple Streets, a bur oak that predates the Declaration of Independence rises to a height of more than 80 feet from the yard outside Long’s Garage.

Farther from the center of town on East Main, a still larger bur oak can be seen on the eastern edge of the site of the Friends Meetinghouse. We can take this tree to be roughly 240 years old now, based on calculations made in 1976, when the International Society of Arboriculture recognized it as a “bicentennial tree.” 

At Leal Park, which is on University Avenue near the Carle complex, there’s yet another bicentennial oak marked with a plaque.

Greater numbers of oaks that predate European settlement can be seen—and hugged—at some other Urbana Park District sites. Some of the largest trees in Crystal Lake Park and Busey Woods are relics of the Big Grove, as are 10 or so of the trees at Weaver Park on East Main Street.

If you’re interested to do a little more reading before you head out on your treehugging adventure, check out the Website “Children of Giants” recently established by UI professor of entomology Stewart Berlocher at

Thursday, September 22, 2016

Entomology student publishes update of 1927 ant survey

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Andrea Belcher came to the University of Illinois five years ago as a graduate student to study ants with entomology professor Andrew Suarez. In her own words, she was “always interested in small things,” and the research opportunities she took advantage of as an undergraduate in her native Texas led her to focus on ants.

[Photo: Two carpenter ants of different species locked in combat. Credit, Selina Ruzi.]

In contrast to many other young biologists, who are drawn to genetic studies and lab work, Belcher was especially interested in the study of her subjects in the field.

That made her an ideal candidate for a project department head May Berenbaum had been hoping to have someone take on, which was to replicate a study of ants in and around homes in Urbana done by a U of I PhD student in the 1920s.

Belcher’s article describing that project is published in the Fall 2016 issue of American Entomologist, under the title “Urbana House Ants 2.0: Revisiting M.R. Smith’s 1926 Survey of House-Infesting Ants in Central Illinois After 87 Years.”

Belcher’s survey had three goals: To identify ant species that infest houses now, to analyze the methods people use to control pest ants, and to compare her results with those found by Smith.

Following in Smith’s footsteps, literally, Belcher focused her study on two intersecting streets that form a cross in central Urbana, an area that encompassed about 300 single-family homes, as well as 40 multi-unit buildings.

Like Smith before her, Belcher relied on the cooperation of residents in the study area. First, she asked them to become “citizen scientists” and collect any ants found within their homes. This was done by capturing the ants on sticky tape and recording some basic information about them: where they were found, how many there were, if and what they were eating and what, if any, measures were used to control them.

In addition, Belcher sought permission from residents for herself and an assistant to walk around their yards once and collect any active ants they found to help determine the total diversity of ants in Urbana. Beyond that, Belcher sampled ants from three nearby fragments of forest, to allow for some comparisons between them and the urban setting.

What changed for ants in Urbana over the 87 years between Smith’s and Belcher’s studies?

Fewer species seem to be inhabiting human residences. Belcher turned up only eight, whereas Smith had 11.

An exotic species, pavement ants, seem to have spread into or increased in abundance in Urbana. They were the fourth most commonly collected species in residences in 2012-2013; Smith had found none of them.

People have adopted safer, more selective methods for chemical control of insects indoors. Survey respondents in the 1920s used broadly toxic chemical controls including compounds containing arsenic and mercury. Respondents from 2012-2013 reported using targeted, “least toxic” compounds, frequently baits that workers carry back to the nest.

Some decline in the total number of local ant species may have taken place. Despite sampling more habitats using a greater variety of methods, Belcher found only 44 species whereas Smith had 47.

For the present, Andrea Belcher’s work no longer focuses on ants. With a spouse in the military, she has landed in Santa Cruz, California, where she works primarily as an interpreter and tour leader at Natural Bridges State Beach. Insects are still part of the picture for her though, as she also assists researchers studying the monarch butterflies that overwinter there.

She, Berenbaum and Suarez all hope her study inspires other entomologists to examine the archives at their own institutions for studies from the past that might be replicated to help us understand how the insect world has changed over time.

Thursday, September 15, 2016

Appreciating nature near at hand

Appreciating nature near at hand

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Even though there’s time on the calendar before Autumn begins officially, we’ve passed some important marks on the cultural calendar. Labor Day is a memory, the new school year is in full swing, and the season of traveling to outdoor destinations is over. For me, that means it’s a great time to renew appreciation for the undramatic nature that surrounds us every day.

Birds are on the move. The peregrine falcon that has spent the past four winters on the U of I campus arrived ahead of the students this year. If you’re on campus, you can sometimes spot him perched high on side of the tall buildings near Fourth Street.

Ruby-throated hummingbirds are migrating, too, and you can attract them to your own backyard by hanging out a nectar feeder. Some hummingbirds linger into late October, and fall occasionally offers the opportunity to see species that don’t typically inhabit the Midwest.

[Photos by author: a ruby-throated hummingbird in the garden; male widow skimmer at the Boneyard; emerging cicada on a backyard tent.]

Birders who really want to take advantage of the season can come out for Sunday morning bird walks led by members of the Champaign County Audubon Society. These walks, which continue through October, depart from the Race Street parking lot at 7:30. Birders of all skill levels are welcome.

At our latitude, the peak abundance of migrating monarch butterflies typically occurs during the second or third week of September, so keep an eye out for them. When you catch sight of one, call to mind this mystery. The monarchs we see heading south in the fall are generations removed from the ones that started north from Mexico in the spring. Yet they’ll somehow navigate to the very same stands of mountain forest where their great great great grandparents overwintered last year. And we think GPS is cool.

Humbler insects also abound now. It’s astonishing to me to think about how many crickets must inhabit the yards in just my own neighborhood. My dog snaps at every one we encounter on the sidewalk, which means our walks take longer as their population booms late in the summer.

Over the prairie at Meadowbrook Park and other natural grasslands, hordes of dragonflies rule the air. But you can also see dragonflies near the margins of just about any pond or creek, even the Boneyard where it flows through town and campus. Learn to identify the male widow skimmer, with his powdery blue body and distinctively marked wings and you may find you’re interested in identifying some of the other dragonflies you see, too.

If you’re near the Boneyard Creek, or any other creek, pluck a berry from a nearby bush and toss it into a deep spot. You might be surprised by the number of fish that bolt out to investigate. Even the derided Boneyard now hosts more than 20 species of fish, thanks to the Clean Water Act.

Late in the day Cicada song still fills the air. Most of this year’s adults have already come and gone, but now and again you can still find one just emerging from the exoskeleton that it wore while living underground. If you’re so lucky, make time to watch the process.

As evening gives way to night and cicadas rest from their singing, bats take wing to feast on the insects that fill the air. You can see the first act of that nightly drama by sitting quietly and training your gaze on a single patch of evening sky.

Thursday, September 08, 2016

An ecological look at acorns

An ecological look at acorns [originally posted 9/25/2014]

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Last week I found a walnut on my windowsill, a big fat one with an unblemished bright green husk. Soon after, another appeared stuck in the wheel of my car. Now they’re cached everywhere around the outside of our house, from the shelf on the grill to the flowerpots on the deck.

Acorns are everywhere now, too, as anyone who bicycles where there are oaks can attest. A person’s got to keep both hands on the handlebars to avoid having them wrenched sideways.   

While these seeds may be present me with minor annoyances, they’re much more interesting and important from an ecological perspective.

Scientists group walnuts and acorns together with hickory nuts and beechnuts in the category of hard mast. This they distinguish from soft mast, which generally refers to fruits like crabapples and blueberries but can also apply to other parts of plants that serve as food for wildlife.

[Photo by author. Gray squirrel eating an acorn in a Chinkapin oak.]

According to Ed Heske, a mammal ecologist with the Illinois Natural History Survey at the U of I Prairie Research Institute, “The most important thing about hard mast from the perspective of wild animals is that it’s storable. Without hard mast many mammals that don’t hibernate in winter would have little to eat.”

Of course, while it’s a good thing for squirrels that acorns can be stored for eating over the winter, it is not in the interest of oak trees to expend all of the resources needed to produce such wonderful seeds if all of them wind up as squirrel food.

Evolution has provided oaks with a clever reproductive strategy to avert that outcome, referred to as masting cycles.

 In most years, oaks produce a sort of baseline quantity of acorns, and populations of animals that depend on them become calibrated to that. But every few years or so, depending on weather and other factors, the oaks of a local area synchronize their energy and produce a bumper crop—up to a hundred times the baseline quantity of seeds in some species. With populations of acorn eaters limited by the leaner years, chances are that some portion of acorns from the bumper crop will go uneaten and grow into the next generation of oaks.

There is another wrinkle to this story, though. Some years back Heske and a colleague conducted a study that found acorns would result in new oak seedlings only if some of them were buried by squirrels and then never recovered, a situation expected primarily when acorns are superabundant in mast years. Otherwise something—whether it was a deer, turkey, mouse or weevil—always ate them up from the soil surface before they had a chance to germinate.

In addition to promoting new generations of oaks, Heske explained to me, bumper crops of acorns initiate a cascade of other ecosystem effects. Extra acorns, for example, enable forest-dwelling mice to reproduce especially well; during mast years they can add an extra litter or two, and add to the size of their litters as well.

Good for the mice, right?

But what’s good for mice is, in turn, good for great horned owls and the other predators that eat mice. They generally experience a bump in reproductive success in the year following a mast year.

Thursday, September 01, 2016

Great strides for home solar thanks to Solar Urbana-Champaign program

Great strides for home solar thanks to Solar Urbana-Champaign program

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You may or may not remember it, but in a commentary last December spoke about my family’s plan to have solar panels installed on our Champaign home in 2016. I’m happy to report we followed through on that, and since late July have had 25 Hanwha Q-Cells up on our south facing, second-floor roof.

The system includes an online monitoring program, so I am able to say that up until now, our best day for energy production was August 6, when it generated 28.17 kilowatt hours of electricity. Our worst was August 15, with only 2.9 kWh generated—that was a gloomy day!

Although these numbers are meaningful to me now, they probably don’t do much to help you get a sense of how much electricity our system produces. Better, perhaps, to say that it’s expected to generate more than 80 percent of our total electricity use over the course of a year.

What’s more important than the fact that my family now has a solar array is that ours is one of 81 arrays that were (or are to be) installed at homes and businesses in Champaign County thanks to the Solar Urbana-Champaign Program.

Solar U-C, you might remember, was initiated by the Urbana Sustainability Advisory Commission, and intended to move the city forward on its Climate Action Plan, the ultimate goal of which is to reduce greenhouse gas emissions attributable to the community by 80 percent. The program secured a discount in the price for rooftop solar by bringing consumers together to buy as a group from a company selected through a competitive bidding process, St. Louis-based StraightUp Solar. StraightUp also partnered with local firm, New Prairie Construction, on some of the installations, including the one at our house.

On the subject of price, there are a few things you might be interested to know. The systems installed with the program averaged around $3.50/kw, which translates to $24,500 for an average size system. A federal tax credit returns 30 percent of that, though, and a state-sponsored program of renewable energy credits returns another 25 percent over five years, so the net present cost would be about $11,000.

Depending on electric use, assumptions about whether and how much electric rates will change in the coming years, etc., photovoltaic systems installed through the program are expected to pay for themselves in savings well within their lifespan.

Ultimately, of course, my family’s decision to go with solar power has more to do with our commitment to helping make renewable energy the norm in Illinois than saving money on our electric bill (although I’m not complaining about that, either). I also like the fact that much of the money we spent to bring electricity to our house in the coming years went to support good, local jobs.

If you participated in the Solar C-U Program, please know that the Illinois Solar Energy Association (ISEA) is looking for host sites for its annual Illinois Solar Tour, coming up on October 1. If you missed the Solar C-U Program but you’re still interested to explore home solar as an option, your best bet is to start with the vendors listed on the ISEA website at