A beautiful invasion

Post by Kelsey Roehrich

I am a student at Iowa State University, and traditions are an important part of school life. One long-standing tradition centers around two swans, Lancelot and Elaine, which float on a small campus lake. Legend has it, walk around the lake three times with your significant other and you will be together forever, since it is said that swan pairs mate for life.

During my time as an intern for the Lake County Forest Preserves in Illinois I have learned a lot, but I never thought I would debunk one of my university’s traditions! Lancelot and Mute swans in Libertyville, ILElaine are mute swans (Cygnus olor), and I found through research that mute swans can have up to four different mates and will often “divorce” each other. Perhaps this is the reason that the tradition may not have worked out for some couples.

Good news for you “love birds,” occasionally mute swans choose only one mate, and those couples typically have a more successful mating season. So not all hope is lost, but as for me, I won’t be making three trips around the lake any time soon.

Mute swans are not native to the United States. They were first introduced to North America in the late 1800s from Europe and Asia for use as living decorations on ponds and lakes, just as they are on Iowa State’s campus. The consequent expansion of mute swans poses significant threats to native wildlife through competition for food, territories and nesting areas. These large birds consume four to eight pounds of aquatic vegetation each day and can uproot about twenty pounds daily. This can rob other animals of food.

Mute swans are territorial and aggressive, especially during mating and brood-rearing season. They drive off other water birds and will attack humans who approach too closely. In 2012, an Illinois man in a kayak got too close to mute swans on a small pond. The swans charged at the man’s kayak, causing him to fall into the water. The swans continued to harass the man, and he drowned before reaching shore. Mute swans are one of the most aggressive waterfowl species. They set up large territories, which can encompass an entire small lake or pond. These combative swans chase off other waterfowl, displacing native species from their nesting and feeding areas. Wildlife biologists are concerned about the decline of native waterfowl species in some areas, such as trumpeter swans.

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The population of mute swans in North America has increased steadily since it was first introduced. There is controversy surrounding the control of non-native mute swans in areas where native wildlife habitat is threatened. Some states, such as Michigan, Minnesota and New York have set policies and goals to manage, and in some cases, eliminate the mute swan population.

As I work on various projects for the Forest Preserves, I’m constantly learning more about their conservation efforts. Unfortunately, the story of non-native, invasive mute swans is just the tip of the iceberg. Invasive species, from the emerald ash borer to garlic mustard, are an issue everywhere, but there is hope! Knowledge is power, and we can all help. Restoration workdays are held every weekend. Visit www.LCFPD.org/restorationworkdays to find upcoming opportunities to make a difference. Instead of circling the lake on campus three times, perhaps I can find my future beloved while restoring the ecosystem…

Spring songs

In May the natural world of Lake County, Illinois clamors for attention. Frogs peep, toads trill, insects buzz and chirp, but the all-stars of the show are birds. Perching songbirds, referred to scientifically as oscine passerines, are known for their amazing and extremely varied sounds. For many small and secretive species, their calls and songs are often the only way to identify individual birds within the chorus.

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Shorter, non-musical bird calls are heard year-round. Calls are used in social interactions and as alarms. They are considered innate. However, scientists have determined that birds’ longer, melodic songs are learned in the first year of life. Birds use these spring songs, some containing several melodies, primarily in establishing territory and breeding. Continue reading

Wood frogs found!

Discovery is often about being in the right place at the right time. This is exactly what happened recently when a wildlife biologist for the Lake County Forest Preserves was in the right woodland on the right spring day. While monitoring wildlife, a biologist heard sounds from the elusive wood frog (Rana sylvatica). The duck-like breeding calls made by male wood frogs had not been heard in Lake County, Illinois since the late 1980s. This discovery is the first sign of victory following extensive habitat restoration and recent species reintroduction efforts.

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Crane chronicles

I am part of a volunteer group for the Annual Midwest Crane Count, monitoring the wetlands and fields in Lake County, Illinois each year for sandhill cranes. In the pre-dawn hours, our eyes scan for any hint of movement. Our ears listen for a bugling sound. Our mission: Determine the abundance and distribution of sandhill cranes (Grus canadensis) in the Upper-Midwest United States.

The arrival of these large elegant birds in Lake County is a harbinger of spring. More migrate through this region every year, and an increasing number are deciding to nest here as well. We know this thanks to the early-rising volunteers who help with the Annual Midwest Crane Count held each spring. This year, some of the first sandhill cranes returning to Lake County, Illinois were spotted in mid-March at Rollins Savanna Forest Preserve. Continue reading

Surviving in the subnivean

This winter has been harsh in Lake County, Illinois, causing many of us to wish we could migrate to South America like some birds do, or hibernate in a cozy underground den like the groundhog.  Alas, most of us just stick it out in the cold. It may offer consolation to know we are not the only animals active during these record-breaking cold, snowy days. It turns out there is a whole ecosystem teeming with life right under the snow.

Recently, scientists having been taking a closer look at life in the subnivean, which literally translates to “a place under the snow.” The space between the snow and the ground acts as a seasonal refuge for invertebrates, birds, and small mammals. Snow affords these small critters with remarkable insulation, and temperatures around 32 F regardless of the temperature above the snow. Biologist Bernd Heinrich explains the science underlying these insulating properties in the book Winter World: The Ingenuity of Animal Survival. “As long as both ice and water exist side by side, they constitute a thermostat keeping temperatures constant.” When water converts to ice crystals, heat releases. When ice turns into water, the process uses up heat.

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A snowy spark

Many years ago, while running along the Lake Michigan shoreline late on an evening in January, a feathered ghost appeared on top of a flag pole. It was the first time I had ever seen a snowy owl (Bubo scandiacus) and it stopped me in my tracks. This was the spark on that frozen night that lighted my fire of curiosity about birds. This winter, snowy owls have left their Arctic homes in record numbers, causing one of the largest irruptions (sudden increase) in northern Illinois in decades.

Although it seems natural to correlate the arrival of these boreal birds with the extremely cold, snowy winter northern Illinois is having, experts say the motivator is more likely linked to food. On their Arctic breeding grounds, snowy owls feast under 24-hour sunshine. Their food of choice is lemmings, small mammals with an extremely cyclical population. Bird expert Kenn Kaufman explains in a recent Audubon magazine article, that when the lemming population explodes, like it did last summer in northern Quebec, snowy owls have great breeding success, producing large broods of up to 11 chicks. As these chicks quickly grow into juvenile birds, the competition grows for the now dwindling numbers of lemmings. Thus, the young birds get nudged further and further away to find a meal, resulting in them moving to areas that mimic their treeless tundra home, such as the Lake Michigan shoreline. Continue reading

Restoring our woodland habitats

Post by Allison

The wooded habitats along the Des Plaines River in southern Lake County, Illinois are changing. Last winter, the Lake County Forest Preserves completed 194 acres of canopy and understory thinning in woodland communities at MacArthur Woods and Grainger Woods Forest Preserves. This winter, woodland habitat restoration has begun at Captain Daniel Wright Woods and Ryerson Conservation Area, in addition to continuing at MacArthur Woods.

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The restoration and species monitoring that will continue within these natural areas for the next 20 years will help ensure the sustainability of oak woodlands and the wildlife they support for many generations to come.

Winter visitors to these preserves, or vehicular passersby, will notice the use of heavy equipment, burning piles of brush, and an already visible difference in the openness of the woodland landscape. A number of canopy trees are being removed to increase the amount of sunlight reaching the ground. Visit these areas again when the leaves return, and early results of the Woodland Habitat Restoration Project will be obvious. Continue reading

Virtual camouflage hike

Leaves throughout the forest glowed gold against a backdrop of graying sky as I left Ryerson Conservation Area yesterday afternoon. This morning—as I entered the same preserve along the same road—the dark, skeletal branches were completely visible, stripped of their vibrant leaves that now lay in muddied piles on the forest floor.

These days of November mark a change from crisp colors to muted tones, which offer the perfect backdrop for animals to hide using camouflage. Lake County Forest Preserve educators often teach the concept of camouflage during environmental programs, where students hike in search of animal hides and mounts that have been hidden along the trail. Teachers and scout leaders, peruse our variety of school and scout programs to find a great fit for your group this year. Following is a virtual version of our camouflage hike. Continue reading

Arachnid architecture

With the warmth we’ve experienced this October, I have spent many mornings drinking my coffee outside, watching the early sunlight glint off strands of spider silk that have encased my tiny porch overnight. While I’m enchanted by this maze of webs, my next door neighbor is not. I’m quickly called next door to clear a web-free path as she rushes down the stairs and off to work. I feel a bit of guilt as it takes me seconds to paw through a huge orb web that I know took the spider hours to intricately create.

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Goldenrod galls

September in Lake County, Illinois is a month of big sky punctuated by tips of tall prairie plants in an array of autumnal colors. Before the trees really get going with their own colorful show, sparks of bright yellow from the many varieties of goldenrod (Solidago spp.) dominate the open spaces. Most of the summer these plants go unnoticed, adding merely another green hue to the lush surroundings, but September is their time to shine. What may also go unnoticed, even now as goldenrod demands our attention, is the hidden world inside each plant in the form of a gall.

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