Crane chronicles

Every year, I am part of a volunteer group, exploring the wetlands and fields in Lake County, Illinois. In the pre-dawn hours, our eyes scan for a hint of movement; our ears listen for a faint bugling sound. Our mission, to spot the arrival of sandhill cranes (Grus canadensis), a sign that heralds spring.

sandhill flyingThese large elegant birds migrate through Lake County 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 in spring. This year, some of the first sandhill cranes spotted returning to Lake County, Illinois were seen mid-March at Rollins Savanna Forest Preserve.

Sandhill Crane wading. Photo courtesy of International Crane Foundation.

Although this species stands roughly 3 1/2 feet tall and has extremely long legs and beak, the birds are often tough to spot—camouflaged by the wetland and prairie backdrops. These habitats set the stage for spring courtship rituals that, like a Broadway production, come complete with costumes, song and even dance.

Wing feathers of a dead sandhill crane, found along the Central Platte River in Nebraska. Photo courtesy Chris Helzer.

Prior to breeding, mated pairs begin their elaborate courting by painting their feathers with mud, which helps them hide from predators. Following the painting, the two cranes leap and fall in dance-like movements accompanied by a loud duet of unison calls.

Sandhill Crane mating dance. Photo courtesy of International Crane Foundation.

After this song and dance, the couple builds a large wetland nest up to 5 feet in diameter made of grasses and other vegetation. The nest rises high above the water, offering the parents a platform to spot predators while surrounded by a protective moat.

The female typically lays two to three eggs, but usually only one chick survives. That’s because siblings aggressively battle each other for food, with the dominant individual emerging. However, in years when their food supply—anything from plants to insects to small mammals—is plentiful, both chicks are more likely to survive. Once the chicks are four to five years old they are ready to start families of their own.

Sandhill crane chick. Photo courtesy of International Crane Foundation.

Sandhill cranes have a storied history in our area. Fossils found in North America that date back 10 million years record it as the oldest known bird species still alive today. Until the late 1800s when hunting and habitat loss extirpated both species from the area, they ruled the skies along with the now extinct passenger pigeon. Sadly, the passenger pigeon’s story ended in 1914 when the last bird died in a zoo, extinguishing the species completely. Fortunately, with help from hunting regulations and habitat protection and restoration, sandhill cranes returned to the area in the late 1970s. Although back, they were still at risk in 1989 when the Illinois Department of Natural Resources (IDNR) placed them on the Endangered Species List.

Numbers today are improving. While the 1996 Crane Count spotted only 23 cranes, the population quadrupled in more recent years. In 1999 the IDNR upgraded their status to threatened. This comeback story would not have been possible if it had not been for people working to help the cranes by protecting and restoring habitat as well as monitoring their progress. This year there is a reminder that not all species have a bright future like the sandhill cranes’. The centennial anniversary of the passenger pigeon’s extinction is an opportunity to explore the connections between humans and the natural world, to face current behaviors threatening wildlife, and to inspire people to become more involved in building sustainable relationships with our world.

For opportunities to explore these connections check out the Lake County Forest Preserves’ free Earth Week programs in honor of Earth Day 2014 on April 22. Or consider becoming a volunteer with the citizen-based Crane Count. Also check Horizons magazine for programs that explore how caring leads to conservation.

 

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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Crayfish tales

When most adults hear someone mention crayfish, what most likely comes to mind is a culinary dish rooted in the South. However, mention crayfish to a group of Summer Campers at the Lake County Forest Preserves, and you will see eyes light up and hands reach for pond-scooping nets and buckets while their minds contemplate questions of “how big?” and “how many?” During our hikes to the edge of a pond the campers exchange crayfish stories about the best techniques for catching these crustaceans, the size of earlier catches growing the closer we get to the water.

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Campfire serenade

One hallmark of a good camping trip in my family is an evening spent huddled around a crackling campfire as the sun and moon exchange places and dusk settles around us. The smell of the fire, the taste of gooey marshmallows smashed into S’mores, the silhouettes of bats and moths in their nightly chase—all create a moment completed only by the haunting calls of whip-poor-wills (Antrostomus vociferus). These elusive nocturnal birds, although rarely seen, announce themselves boldly by calling their own name over and over again in a seemingly endless serenade.

The eastern whip-poor-will is part of the Caprimulgidae family of nocturnal birds commonly called nighthawks and nightjars. Robin-sized and cloaked in impressive camouflage, whip-poor-wills breed in open woodlands and nest on the ground. Their nest is a shallow area among the leaf litter that is carved out by the weight of the incubating parent and two eggs. Whip-poor-wills have been known to lay their eggs in phase with the lunar cycle, so that the chicks hatch about 10 days before a full moon. Thus, the parents can take advantage of the longer and brighter light of a waxing moon to forage an abundance of flying insects when the chicks are at their hungriest. Continue reading

Ant parade

With June comes the arrival of many eagerly awaited events. It’s the end of the school year and the beginning of a season of bare feet, beaches, camping trips and baseball games. In my house, one thing we are not excited about is the return of ants that parade around our kitchen. We know these ants are not going to cause us any harm. But, when a horde of them begins an organized march around the rim of my sons’ cereal bowls, it starts to bug me. At the same time, I realize they are just doing their job. It is a highly evolved social structure that allows these ants such precision in the tasks at hand—carrying away crushed Cheerios from the kitchen floor for their own pantries, taking to the air for a ritualized mating flight, deciding which eggs will be fertilized, or starting a new colony from the ground up.

Marching ants

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