Academy History – The 1941 Conservation Effort for the Ants at Palos Hills

One such effort in 1941 saved colonies of the mound building ants, Formica ulkei, that made their home in Palos Hills. The ants came under scrutiny when the land on which they made their home was purchased by the Young Men’s Christian Association (YMCA). The YMCA was concerned that the ants would cause harm to the people that would come visit the campground they were going to establish. Accordingly, they contacted a representative at the Illinois State Natural History Survey to ascertain the best way to destroy the colony. This representative quickly alerted those individuals he knew had been monitoring the colony, and Dr. Eliot C. Williams, Assistant to the Director of the Chicago Academy of Sciences spearheaded the effort.

The Academy published an article on the ants by Alton S. Windsor in its publication, The Chicago Naturalist, entitled “Pyramids of Palos” in October 1939. The colony had been located by Windsor and Dr. T.C. Schneirla in 1931 following local reports of the presence of numerous mounds. They found dozens of mounds at that time and confirmed that the species was Formica ulkei. This particular ant species was only found in a few areas in the Chicago region. The mounds ranged in size from about eighteen inches in diameter and ten to twelve inches in height to as large as seven feet in diameter and three feet above the ground. Windsor continued to visit the site and monitor the ants over the years and he and Schneirla returned together to the site in August of 1939. While some of the mounds had been abandoned due to human intervention or natural progression, the ants as a whole were thriving; a census conducted a few years earlier of just a few acres gave a total number of over 400 mounds!

The YMCA was uninformed as to the scientific importance of the colony when they initially inquired into their removal, but upon receiving letters from Dr. Williams, Jr. and other local scientists, began working with him to formulate a way of using the ant colony to further education about the species and its importance, instead of destroying them. The YMCA and the Academy drew up an agreement in which visitors to the Palos Hills Camp would be informed of the scientific importance of the ants, visitors observing the ants could record their findings, the Academy would have permission to relocate ant mounds located on proposed building sites, and a small sign would be erected at each mound site to help protect the ants “against injury and unthoughtful acts”. In addition, the signs would be numbered so that the observations made by visitors could be accurately recorded and a “history” for each mound could be established.

Today this species is no longer present in Palos Hills and not much is known about the effort and why and when it ended or even where the proposed visitor records are now. Williams was drafted in July 1942 and served in the Army until March 1946. Many others from the Academy and the scientific community joined Williams, leaving the Academy and other organizations with a skeletal staff during the war years. It was perhaps this absence and the increased responsibility of those who remained stateside that led to the decline in the oversight of this site, but we can only speculate. While this effort did not culminate in the continuation of the Formica ulkei at Palos Hills in perpetuity, the open dialogue created on both sides of the issue resulted in fruitful discussion and compromise.

Greenberg, Joel, ed. Of Prairie, Woods, and Water: Two Centuries of Chicago Nature Writing. Chicago: University of Chicago Press, 2010, pp. 457-468.

Windsor, A.S. “Pyramids of Palos.” The Chicago Naturalist, Vol. 2, No. 3: October 1939, pp. 67-72, 91.

Chicago Academy of Sciences Institutional Archives