The decade of the 1990s began with chemist John Guyon (former Dean of the College of Science) as President of SIUC, zoologist Ben Shepherd as Vice-President for Academic Affairs and Research, botanist John Yopp as Dean of the Graduate School, and geologist Russell Dutcher as Dean of the College of Science. Undergraduate enrollment was just over 20,000 and graduate enrollment was approximately 3,600. Lawrence Pettit was Chancellor of the SIU Central Administration. Yet, soon the titles switched; the head of the SIU Central Administration became known as President, and each campus was subsequently led by a Chancellor. In the Department of Zoology, the position of Chair shifted from Lee Drickamer to Roy Heidinger in 1991 and then to William Muhlach in 1994. Jack Parker became Dean of the College of Science by 1994.
At the onset of the decade, Zoology listed 77 courses in the Bulletin. The number increased to over 90 by the end of the decade. Changes included splitting Wildlife Biology into two courses (Wildlife Biology Principles and Wildlife Techniques) and adding new classes, such as, Wildlife Toxicology, Wildlife Habitat Analysis, Curation of Biological Collections, Computer Techniques in Systematic Biology, Developmental Gene Regulation, and Molecular Genetics Techniques.
During the '90s, undergraduate Zoology majors fluctuated from 200-260, slightly less than that of Biological Sciences. Graduate enrollment in Zoology exceeded 100 a few years in the mid-'90s. And the Department took pride in having graduated over 600 with Master's degrees and over 115 with PhD degrees. The first Master's degrees were awarded in 1949 and the first PhDs in 1964.
The number of teaching faculty hovered around two dozen throughout the '90s. The faculty who retired included Ronald Brandon, DuWayne Englert, Roy Heidinger, and Eugene LeFebvre. Faculty who departed for other opportunities included Neil Billington, Lee Drickamer, Robert Gates, Walter Jakubas, Michael McKee, Jonathan Newman, Ann Phillippi, Daniel Roby, and James Seeb. New faculty were added to the roster. The Department was sad to learn of the deaths of former faculty -- Harvey I. Fisher, William G. George, Willard D. Klimstra, Jan Martan, and Thomas Tacha.
Although most of the Department remained in Life Science II, during the '90s the newly constructed Life Science III became office and research space for some of the departmental faculty. This supplementary building also provided space for the SIUC Ichthyology and Herpetology Collections.
As the decade ended, the Zoology faculty included William Muhlach (Chair), Frank Anderson, Terence Anthoney, Joseph Beatty, Thomas Breen, Brooks Burr, Bruce Dugger, William Dyer, George Feldhamer, Richard Halbrook, Edward Heist, David King, Christopher Kohler, Carey Krajewski, Karen Lips, J. E. McPherson, Matthew Nicholson, Robert Sheehan, Benjamin Shepherd, John Stahl, George Waring, and Alan Woolf.