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Unprecedented Forty-Year Study Released / Research eSeries Launced

  Unprecedented Forty-Year Study Released / Research eSeries Launced   

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For More Information & Content Call:
Bonnie Styles, Museum Director 217.782.7475
For Images Call:
Jennifer Snopko 217.782.5949

PRESS RELEASE: Illinois State Museum, Springfield

Unprecedented Forty-Year Study Released.  Thirty-seven years, 11,819 field days, 61,626 field hours, 29,568,184 individual birds, 359 bird species, and three additional years of observations in which numbers were not added, but noteworthy discoveries were documented.  If anyone understands the birds of Sangamon County, and the recommendations for preserving and encouraging a rich diversity of species, it’s H. David Bohlen, Illinois State Museum’s Assistant Curator of Zoology.  In Malcolm Gladwell’s book Outliers, he claims that to become an expert in any field, one must complete around 10,000 hours of practice.  With his passion for birds and his concern for their dwindling populations and visits, Bohlen has multiplied this number six-fold and has no plans of stopping anytime soon.                     

40 Year Study Released
Birds of Sangamon County
Research eSeries

A Study of the Birds of Sangamon County, IL, 1970-2010 is the debut release of the launch of the museum’s new Research eSeries.  The eSeries is available on the museum’s website free of charge to the public and showcases the research of scientists and other staff of the Illinois State Museum.  The series will allow the museum to more readily share and update its findings.

Bohlen’s inaugural release documents the dramatic changes in the presence and populations of bird species in Sangamon County.  His two-part compendium explores environmental change, habitat destruction, and degradation by humans as well as outlines methods, conclusions, and recommendations.  It also offers a vast compilation of the county’s bird species, many of which have been beautifully photographed and aptly featured in part two of the study.  Bohlen has added another 88 species to the Sangamon County List.

Bohlen hopes that this condensed compilation of years of data, interpretation, and personal experience makes people more aware of the numbers and species of birds in the county.  He explains, “Fluctuating populations can be up to good numbers and then down to zero… In the past few years there has been too much disturbance and loss of habitat.  If I’ve learned anything, it’s that things are constantly changing, but if you don’t watch what you do, species will be lost.  As far as today… the Loggerhead Shrike is pretty much gone.”

Many species of birds were already disappearing in Sangamon County when Bohlen started his observations.  As years went by and as migration cycles continued, Sangamon County became less and less of a welcoming stop along the way.  Throughout the 40 year study 355 species were recorded (plus four hypothetical), 95% of which were migrants, and only 5% permanent residents. Bohlen witnessed the number of migrant birds visiting the area shrink and watched the frequency of those visits slowly diminish.  At the same time, he noticed intrusion of human behaviors into parks, reserves, and what were once formerly quiet, undisturbed, untouched areas turned to roads, pedestrian traffic, farmland, and other developments.

Bohlen outlines the steps that lead to bird extirpation: “(1) the species became difficult to find, and this could be shown not only by fewer individuals, but by later arrivals and earlier departures and gaps in migration; (2) the species was reduced to a preferred habitat, so that the observer had to specifically search for it; (3) then, the species was even difficult to find in the preferred habitat; and (4) years passed and none were found.”  (Bohlen, David H., 2013, Study of the Birds of Sangamon County, Illinois, Illinois State Museum Research eSeries, No. 1, Part 1, pg. xxxi)

He accounts for 15 breeding species that have been lost from Sangamon County:

Pied-billed Grebe               Least Bittern                      Yellow-crowned Night Heron
King Rail                          Virginia Rail                        Sora
Common Moorhen              Upland Sandpiper                Black-billed Cuckoo
Whip-poor-will                  Brown Creeper                    Bewick’s Wren
Loggerhead Shrike              Cerulean Warbler                Western Meadowlark

Bird Preservation: Often, Less is More.  Bohlen has outlined general, simple principles, as well as made specific recommendations for reviving and encouraging the return of many bird species and populations.  The study highlights the need for adaption on both ends: birds must adapt to humans (as well as a changing climate), and we must adopt practices to promote biodiversity. 

Recommendations include the c
reation of undisturbed marsh, grassland, and woodland habitat; changes in habitat management practices; taking steps to reduce noise and traffic; and resigning from excessive mowing, tree cutting, and other interferences.  He suggests merging the forests of Carpenter Park Nature Reserve, Riverside Park, and Gurgens Park and linking state parks and nature preserves using dendritic river systems.

Specific suggestions include leaving the sunflower fields used for dove hunting at Sangchris Lake State Park standing rather than plowing them down so as to provide winter food for songbirds.  He suggests adding an ecologist to the Springfield Park District staff to make sure we are doing the right things with the preserve land we have.  He would like to see a standard set that precludes mowing of grasslands until September to avoid disturbance of nesting birds.  The large numbers of birds lost to television tower kills could be reduced by changing stationary lights to strobe lights.  Lowering the speed limit on roads surrounding parks and preserves would lessen disturbances of the quiet needed for bird habitation.  Relative to management of habitat for birds, usually less is more.

For a full list of – oftentimes – simple changes that can have a lasting impact on county bird preservation, simply download the study free of charge.  Most of the time, these changes require less energy, not more.

Why It Matters.  Bohlen will open your eyes to the fact that undisturbed, diversified preserves are actually rare in Sangamon County.  We must strive to preserve what little land we have left that is suitable for bird habitat and attempt to recoup what has been lost. 

Read It. Visit to access the museum’s new Research eSeries and to discover a world now understood thanks to the expertise, exploration and commitment of H. David Bohlen. 

The Illinois State Museum inspires discovery and caring about Illinois’ cultural and natural resources and heritage. The Museum integrates its original research and diverse collections to advance knowledge and create thought-provoking exhibitions and educational programs and resources. These offerings engage people of all ages in their own discovery and lifelong learning about the natural and cultural heritage of Illinois and its place within the world. The Museum promotes stewardship of this heritage to improve quality of life and ensure a sustainable future.

Wednesday, February 05, 2014

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