Illinois Natural History Survey - University of Illinois

**2020 SPRING BIRD COUNT: MAY 9th** 


Spring Bird Count History

The first Spring Bird Count, SBC, was organized by Chandler Robbins, organizer of the North American Breeding Bird Survey, in 1959.  A decade later the Illinois Department of Natural Resources asked Vernon Kleen to organize the first Illinois statewide SBC in the early 1970's.   Vern had been mentored by Chandler Robbins and also helped with the first SBC in Maryland making him a great candidate for taking on such a large task. With the help of Illinois Audubon Society the first count was conducted on Saturday, 6 May 1972 and included 650 observers in 62 counties.  Vern continued organizing the count for over 30 years, before transitioning the count to the Illinois Natural History Survey.  Today the survey has electronic SBC data dating back to 1975.  Each year SBC reports are published in the Meadowlark a journal of the Illinois Ornithological Society, where along with Illinois Audubon many of the counts volunteers come from.

About the Count

Spring Bird Count is a yearly bird count that consists of volunteers conducting bird censuses on the Saturday that falls between May 4th and May 10th. The censuses are conducted in all 102 counties in Illinois, however in any given year a few counties are not censused. Each county has a compiler responsible for recruiting volunteers and assigning them areas to count within their county.  This is especially important to avoid double coverage of an area.  Compilers also tabulate all data collected within their county and send it to the state compiler.  Volunteers record all birds seen or heard, along with the number of hours they spend "owling" (pre-dawn hours), the number of hours spent looking for birds during the day, the number of miles driven in a car, and the number of miles walked. 

About the Database

The Illinois Natural History Survey is providing this website to allow both the thousands of volunteers, and other interested parties with the ability to view the nearly 40 years of data. When searching through the data please let us know of any errors, as there could possibly be some. The data generated from the Spring Bird Count can be used to estimate changes in populations of species throughout the state. Below is a graph of the number of crows detected per party hour throughout Illinois and in Cook County (i.e. Chicago). The graph shows a large decline in their population after the arrival of West Nile virus in Illinois. The next series of graphs shows the changes in selected species. Henslow's Sparrows, Double-crested Cormorants, and Wild Turkeys have shown large increases, Loggerheaded Shrikes and Upland Sandpipers show large declines, and Swainson's Thrushes exhibit very large fluctuations from year to year, which are probably correlated with regional weather patterns affecting migration.

It also should be noted that because of the nature of the data, declines or increases in certain species population trends may not accurately reflect true changes in populations and statistical tests should be preformed to determine if observed trends differ from a stable (no change) trend. Please contact Tara Beveroth ( or Michael Ward ( for questions about the data or errors detected in the data.

Click to view any of the following graphs (each will open in a new window):

Illinois Natural History Survey

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