In the fall of 2003, I began a long-term survey of the winter bird community at Sand Prairie-Scrub Oak Nature Preserve in Mason County, Illinois, as part of a baseline survey for National Audubon’s Important Bird Area program for Illinois. I was specifically interested in the preserve’s overwintering red-headed woodpeckers, a species known to be experiencing a steady population decline in many areas of its range.
Except for 2008, I have since completed one to four counts per winter season. Background information for this survey is summarized in an article entitled The Missing Red-headed Woodpeckers of Sand Prairie-Scrub Oak Nature Preserve, which can be located on this blog by clicking on this link. An updated chart is shown below with data from the latest count on 2 December 2014.
The numbers of red-headed woodpeckers that may be found overwintering in a given area are known to be correlated with the amount of mast available, usually oak. While I had not collected information on mast during this study, to my regret, during the fall of 2014 I did notice numerous acorns beneath all oak trees that I checked at Sand Prairie-Scrub Oak Nature Preserve and at other areas in Mason County. So I was expecting at least an average count of red-headed woodpeckers as I completed my winter 2014-15 count. The count was, in fact, a record high for this particular survey. The count of blue jays, a species that competes with red-headed woodpeckers for oak mast, was also a record high.
For an update, see this link.