LISLE ARBORETUM CHRISTMAS BIRD COUNT
Count History

Assembled here is some information about the Lisle Arboretum Christmas Bird Count (or CBC), records from past years, and summaries from some recent years' counts. Information about the Christmas Bird Count program in general can be found at http://www.audubon.org/conservation/science/christmas-bird-count on the National Audubon Society (NAS) web site. NAS organizes this winter bird census nationwide.

The Lisle Arboretum Christmas Bird Count was first held in 1937. Over the next two decades it was held sporadically, with counts in 1938, 1940, 1942, and 1945 through 1947. However, from 1956 through the present the Lisle Count has taken place every year (though in 1978 the totals were never reported to the National Audubon Society).

There have been 156 different types of bird recorded on the Lisle Count, with one more recorded during "count week" (the three days before and the three days after the actual count day). The highest single count total was 90 species of birds seen on count day, with that total achieved in 2015. A high total of 91 species including count week birds was tallied in 2013 and then matched in 2014. The largest number of individual birds counted was 42,754, which happened in 2005.

Summary of records for the entire count history:

  • Lisle-Arb Records in taxonomic species order (pdf document - updated 11 February 2018), including maximum single-year count and the year achieved; the average number by species for the history of the count, the last 30 years, and the last 15 years; and the number of years seen over all counts, over the last 30 counts, and over the last 15 counts.
  • Lisle-Arb Records in "code" order (pdf document - updated 11 February 2018), with the same information as above. We split the list of birds into
    • Code 1 - birds that are seen every year in each of the six areas of the circle;
    • Code 2 - birds that are seen every year, or nearly every year, in the count circle, in three or more of the six areas;
    • Code 3 - birds that are seen at least once every four years, and usually not in each area;
    • Code 4 - "good birds" that are highlights of the count. Code 4 birds are listed in decreasing number of years they've been recorded on the count.

Summary of records for recent counts:

Last modified on 11 February 2018
by Geoffrey A. Williamson