Thursday, June 27, 2013

An update on endangered mussels reintroduced in the Middle Fork and Salt Fork of the Vermilion River

An update on endangered mussels reintroduced in the Middle Fork and Salt Fork of the Vermilion River

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Over the past three years, scientists from the Illinois Natural History Survey have translocated hundreds of mussels from the Allegheny River in Pennsylvania (where they lived beneath a bridge slated for demolition) to sites on the Middle Fork and Salt Fork of the Vermilion River.

The two species of mussels involved, clubshells and northern riffleshells, are both classified as “endangered” by the federal government, and by dint of that status they are subjects of recovery plans coordinated by the U. S. Fish and Wildlife Service. Those plans call for them to be reestablished throughout their historical range, which includes Illinois.

I had the opportunity recently to tag along with scientists from the Survey on a trip to check on some of those translocated mussels at a site on the Salt Fork River.

How do you check on mussels?

Under normal circumstances, it’s possible to see some of them just by looking into a stream if the water is both shallow and clear enough. That’s because mussels spend some of their time poking up from the streambed, or even entirely exposed. But mussels also spend time buried beneath the streambed, so scientists find them by “grubbing,” which is digging around in the sand and gravel with their hands.

Fortunately, checking on the translocated mussels is easier than all of that, because they had coded tags epoxied to their shells before they were placed in the river. That enables scientists to find them using an electronic reader, which looks very like a standard metal detector, and is used in much the same way.

Wielding the reader was Austin Haskett, a summer technician who is also a student in the U of I Department of Natural Resources and Environmental Sciences. He began slightly upstream of where the mussels were released last year and worked his way back and forth across the river in partially overlapping strips. Each time the reader picked up a signal, he called out the number from the display and it was recorded on an inventory list by another member of the team.

[Photos by author: Jeremy Tiemann (snorkeling) Austin Haskett and Rachel Vinsel of INHS at work; a clubshell mussel picked up for closer inspection.]

At the same time, other scientists snorkeled in the river to inspect a sampling of the endangered mussels visually.

During the day’s work, a total of 286 tagged mussels were located, just over half of the ones placed there. “That’s about what we would expect,” explained Jeremy Tiemann, the Natural History Survey field biologist who is leading the translocation effort in Illinois. “Others may have been so close together or so deep the reader didn’t pick them up. It’s also possible some moved up or downstream a little ways.”

In overall terms Tiemann is pleased with how the translocation project is going. He said, “It may be some time before we see evidence of these animals reproducing successfully, but up to now there have been no surprises.”

You may be wondering what has changed in our rivers that makes it possible to reintroduce animals that were wiped out more than a century ago. I put that question to Kevin Cummings, who is senior research scientist and curator of mollusks in the Natural History Survey’s Center for Biodiversity. “The short answer,” he replied, “is the Clean Water Act. That, and some changes for the better in agricultural practices.”

He continued, “mussels are still one of the most endangered groups of animals in North America, but the improvements we’ve seen in recent decades provide a glimpse of what’s possible when we treat our waterways with respect.”

Tune in next week to hear about the rediscovery in the Illinois River of a mussel species that hadn’t been documented there since the late 1800s.

Thursday, June 20, 2013

Appreciating, maintaining Horseshoe Bottom Nature Preserve

Appreciating, maintaining Horseshoe Bottom Nature Preserve

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There’s no better way to fully appreciate the beauties of a nature preserve or understand the efforts needed to maintain one than spending time with the people who take care of it.

So recently, I took advantage of an opportunity to accompany such a group for a day at Horseshoe Bottom Nature Preserve, which lies within Kennekuk Cove Park in Vermilion County.

Horseshoe Bottom is not a site most people are likely to visit. Access to it requires a fair bit of hiking on unmarked trails, and only a few boundary signs even tell visitors they’ve found the place. But it’s a site that supports a magnificent diversity of plants and animals I think you might be interested to know about all the same.

The leader of our group was a friend of mine, Rick Larimore, who is retired from work as a wetland ecologist for the Illinois Natural History Survey and who has served as volunteer site steward at Horseshoe Bottom since the mid 1990s. In this role, he seeks to maintain the ecological integrity of the site, primarily by controlling exotic, invasive plants.

The other members of the crew were Joe Boise and Will Wright, college students who are employed this summer as interns by the Urbana-based conservation group Grand Prairie Friends.

Our first business of the day was to check some traps that Illinois Department of Natural Resources scientists have set to monitor for turtles in a shallow swamp at the preserve this summer. Unfortunately, we found the traps empty, as they have been nearly every day since they were first set out at the beginning of the month. The only turtle caught so far has been a snapping turtle, and it’s another species, Blanding’s turtles, that is the primary target of this effort.

To make matters worse, raccoons had torn into the traps and chewed open the cans of sardines being used for bait. We repaired the traps and reset them, although nobody seemed very hopeful that the next day would turn up any Blanding’s turtles either.

Before leaving the swamp, we took time for a closer look at some of the many amphibians it supports. Everywhere the water was alive with larval salamanders, dark, two-inch long creatures that resemble the tadpoles of frogs and toads. Some of these already exhibited the legs and other features that will enable them to graduate to life on land as the swamp dries up over the summer.

The margins of the swamp were quite lively, too, with tiny cricket frogs so thick it was difficult to set a foot down without stepping on them.

By midmorning, we were headed through the forest to a drier, more open site overlooking the Middle Fork of the Vermilion River. There, the mission was to kill autumn olive and multiflora rose, two exotic, invasive plants that would crowd out much of the native plant life if left unchecked. This is done by spraying herbicide on the bark at the base of targeted plants.

While work went on there, we made a point of identifying the birds that called nearby. Among them were some fairly common ones, such as eastern wood pewees, indigo buntings and red-eyed vireos, as well as others that birders get more excited about, especially a Kentucky warbler.

We finished the workday at a prairie restoration on the upland adjacent to Horseshoe Bottom, where autumn olive and multiflora rose are also a perennial problem. Unless someone goes to the trouble of knocking them back each year, Larimore assured me, the prairie restoration would soon give way to a dense thicket providing no enjoyment for people and extremely poor habitat for wildlife.

 If you are interested learning more about some of the unique natural areas in our region, and equipping yourself to help maintain them, check out the East Central Illinois Master Naturalist Program administered by University of Illinois Extension. The program is now accepting applications for the fall training session. Call 217-333-7672 or find them online at

Thursday, June 13, 2013

U of I student replicating 1927 study of ants in Urbana

U of I student replicating 1927 study of ants in Urbana

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Andrea Walker came to the University of Illinois in 2011 as a graduate student in the Department of Entomology intending to study ants with 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.

In contrast to many other young biologists, who are drawn to genetic studies and lab work, Walker is 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.

That study, titled “Ants of a typical middle western city, with particular reference to the house-infesting species,” was conducted by Marion Russell Smith, who went on to a long and illustrious career as an ant scientist.

There are three goals of Walker’s survey. She intends to 1) identify ant species that infest houses now, 2) analyze the methods people use to control pest ants and 3) compare her results with those found by Smith.

Following Smith, Walker is focusing her study on two intersecting transects that form a cross in central Urbana. Currently the study area encompasses about 300 single-family homes, as well as 40 multi-unit buildings.

Like Smith before her, Walker is relying on the cooperation of residents in the study area. First, she asks them to become “citizen scientists” and collect any ants found within their homes. This is 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, Walker seeks permission from residents for herself and an assistant to walk around their yards once and collect any active ants they find to help determine the total diversity of ants in Urbana.

Last year, people at 30 residences participated actively in the study. Those included 18 households reporting no ants were found, and 12 where ants were observed and collected indoors. In her outdoor sampling last year, Walker collected more than 3000 ants at 70 residences. Among these were ants representing about 40 species in 13 different genera.

How do Walker’s findings from the first year of her study compare to Smith’s from 1927?

The most significant difference she has noted so far is a decline in the diversity of the ants collected by residents inside their houses. Smith’s volunteers collected 11 species of ants, while Walker’s have collected only five.

Walker’s field work continues this summer. If you are an Urbana resident and you are curious about the ants you find in your house or around your yard, she would be interested to hear from you. Better still, if you live in her study area and you would be willing to participate by collecting ants, please contact her via email at

The following link takes you to the map of her study site: