About

Thank you for reading. This blog is an active effort to keep readers informed of current natural events and to offer helpful suggestions for exploring local nature niches in Lake County, Illinois. For many people, “Nature” starts with a capital “N.”

When asked to think of meaningful experiences in the outdoors, many minds automatically turn toward the grand vistas of huge National Parks or long road trips to faraway destinations. But what might be most beneficial for our health and environment is finding nature niches closer to home. Connect daily, not once a year. Explore the trails, and find your niche in the Lake County Forest Preserves.

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About the author  Jen Berlinghof is a graduate of Loyola University and The National Outdoor Leadership School, as well as a Certified Interpretive Guide through The National Association of Interpretation. Her work as an outdoor guide and naturalist has taken her from the canyon lands of Utah to the shores of Lake Superior. Since 2003, she has been discovering nature near her hometown and working as an Environmental Educator for the Lake County Forest Preserves in northern Illinois.

Jen birding yellowstone

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Behind the scenes  Assisting with editing and photography is Allison Frederick. She is Assistant Public Affairs Manager for the Lake County Forest Preserves. She is an active citizen scientist, surveying calling frogs and Odonate populations in Lake County, Illinois. Her background in Forestry and Natural Resources from Purdue University and passion for land stewardship is a great fit for the public relations team at a conservation agency. She believes that we can join forces to take major action against climate change and other environmental challenges. From restoration workdays in local preserves to exploring natural areas with her family, she works daily to inspire positive changes in the world around us.

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Behind the scenes  Brett Peto has served as Environmental Communications Specialist for the Lake County Forest Preserves in northern Illinois since 2017. A graduate of Elmhurst College in 2015, Peto edits copy, selects and retouches photos, and ponders the Latin roots of species names in his spare time. Ever since his first science column in the college newspaper, Peto has found fun in the broad accessibility and deep understanding of complex subjects that effective science writing requires.

© Peggy Notebaert Nature Museum

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Guest author Andrew Rutter joined the Natural Resources Department of the Lake County Forest Preserves as a Wildlife Biologist in 2016. But he was already a familiar face, as he had worked as a Southern Illinois University wildlife field technician in various forest preserves. Andrew has a Bachelor’s Degree from Emporia State University and recently received his Master’s Degree from SIU with the Cooperative Wildlife Research Lab studying river otter ecology.

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Guest author Alyssa Firkus joined the Education Department of the Lake County Forest Preserves as an Education Manager in October 2018. Alyssa holds a Bachelor’s Degree in Biology from Humboldt State University and a Master’s Degree in Environmental Education from Western Washington University. Her work in environmental education has taken her around the world, from Australia to Alaska. She now enjoys going on local adventures with her family.

 

 

 

 

 

 

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Guest author Nan Buckardt, a long-time Lake County Forest Preserves employee, has seen many changes to the preserves during her career. As Director of Education, she puts her B.S. in Zoology and M.S. in Education to good use. The Education Department team helps tell Lake County’s natural and human history story. Nan spends much of her free time in nature with her family, especially enjoying birdwatching.

 

 

 

 

 

 

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Guest author Pati Vitt joined the Natural Resources Department of the Lake County Forest Preserves in late 2018. She holds a Ph.D. in Botany from the University of Connecticut, an M.S. in Botany & Plant Pathology from the University of Maine, and a B.A. from College of the Atlantic in Bar Harbor, Maine. Having grown up botanically in Maine, she considers plants that are found in boreal forests as old friends, and is happy when she finds them and other new friends in Lake County. Prior to joining the Forest Preserves, Pati worked for nearly 20 years as a Conservation Scientist at the Chicago Botanic Garden.

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Guest author Ken Klick has worked as a Restoration Ecologist at the Lake County Forest Preserves for 25 years. He finds joy and solace in looking at birds. His career has involved restoring and managing native plants and animals for more than 40 years.

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You may contact us at jberlinghof@LCFPD.org and afrederick@LCFPD.org.

Recent Posts

The cunning of cowbirds

Post by Jen Berlinghof

Bird migration is well underway, and the nesting season is upon us at the Lake County Forest Preserves in northern Illinois. I watched last week as an American robin (Turdus migratorius) plucked dried grasses from the yard, nudging them into place with her beak and wings, readying her cup-shaped nest for the azure eggs that are synonymous with spring. From the nearby American sycamore (Platanus occidentalis) tree, I heard the gurgling chatter of a flock of brown-headed cowbirds (Molothrus ater).

I thought about how while the robin might’ve seemed completely absorbed in her nest building, she was probably wearily listening to the cowbirds, too. Brown-headed cowbirds are North America’s most common avian brood parasite, forgoing nest building altogether. Instead, they lay their eggs in the nests of more than 200 other species of birds, leaving the incubation and rearing of their young to these unwitting foster parents.

A female brown-headed cowbird (Molothrus ater) spotted at Rollins Savanna in Grayslake. Photo © Phil Hauck.
A female brown-headed cowbird (Molothrus ater) spotted at Rollins Savanna in Grayslake. Photo © Phil Hauck.
A cowbird egg waits to hatch among "adoptive" robin egg siblings. Photo © Ted Kinsman.
A cowbird egg waits to hatch among “adoptive” robin egg siblings. Photo © Ted Kinsman.

Historically, cowbirds were commonplace only in the open grasslands of the Great Plains. They followed bison herds, and subsisted on insects flushed by these grazing beasts and seeds foraged from the ground. Yet cowbird populations have surged and expanded as human development has spread—fragmenting forests and creating a patchwork of agricultural land, as well as footholds for cowbirds to now flourish abundantly from coast to coast.

A flock of cowbirds. Photo © Greg Lavaty.
A flock of cowbirds. Photo © Greg Lavaty.

Without the burdens of nest building and chick rearing, female cowbirds have the time and energy to focus on egg production. They create as many as three dozen eggs each breeding season. While they will lay their eggs in a variety of species’ nests, genetic analysis shows that most individual females specialize on one particular host species. It’s hard to imagine, but most hosts don’t recognize cowbird eggs and chicks as different from the norm. They raise them as their own without ruffling a feather.

A dark-eyed junco (Junco hyemalis) feeds a cowbird chick. Photo © Bob Gunderson.
A dark-eyed junco (Junco hyemalis) feeds a cowbird chick. Photo © Bob Gunderson.

Cowbird development moves fast, enabling the chicks to gain an advantage at the expense of the hosts’ chicks. For starters, cowbird females lay their eggs more quickly than other birds—sometimes in under a minute—compared with the 20-100 minutes most passerines take. And cowbird eggs hatch earlier than others, making them the biggest chicks in the nest. This allows them to nudge their smaller, “adoptive” siblings out of the way when meals arrive from a parent. Cowbird chicks sometimes smother other nestlings, or even toss out the host’s eggs and smaller babies.

There are a few host species that have “cracked the cowbird problem.” They see the cowbird eggs for the intruders that they are and fight back. Larger species, such as robins, puncture or toss cowbird eggs out of their nests. Smaller species, such as yellow warblers (Setophaga petechia), that are too tiny to lug cowbird eggs out of their nests reject this role of foster parent foisted on them in a different way. They weave another layer of grasses on top of the trespasser egg, thereby preventing incubation. New research also suggests the yellow warbler’s warning call for brown-headed cowbirds might also benefit eavesdropping red-winged blackbirds (Agelaius phoeniceus), another common parasitic target for cowbirds.

Even though the cowbird adults aren’t involved with the rearing of their own young, it appears that, in some cases, they don’t abandon their chicks entirely. They keep an eye on their offspring periodically, and notice if a host removes or destroys an egg. This can trigger a retaliatory reaction from the adult cowbirds, called “mafia behavior,” in which they penalize hosts that remove their eggs by destroying the hosts’ eggs and nestlings. As it turns out, hosts are better off accepting the parasitic cowbird eggs and end up producing more of their own offspring when they do.

A male cowbird. Note the thick, conical bill. Stock photo.
A male cowbird. Note the thick, conical bill. Stock photo.

The fledgling cowbirds leave the adoptive nest about 10 days after hatching and gain independence from foster parents after about a month. At this point, they find and join a flock of cowbirds in the area and carry on their lives. Regardless of whether we humans see this behavior of brood parasitism as savvy or sinister, it has proved effective and is the hallmark to brown-headed cowbird survival.

While cowbirds have contributed to the decline of several endangered birds, such as Kirtland’s warblers (Setophaga kirtlandii) and black-capped vireos (Vireo atricapilla), they are a native species and thus protected under the Migratory Bird Treaty Act of 1918. As tempting as it may be to step in and remove parasitic eggs from host nests, taking eggs is illegal without a permit. Additionally, it’s been found that due to “mafia behavior,” and to the fact that many hosts assume the cowbird egg is part of their clutch and will have a nest-desertion response if a certain proportion of their eggs is removed, it’s best to leave them alone. Letting nature sort it all out, as with so many other facets of life, is the appropriate course.

While we’re on a bird note … if you’d like to learn the songs of migrating birds and tips to identify them, register for our FREE virtual Bird Walk and Listen programs on April 29 and May 6, 8-8:30 am.

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