Robert Ricklefs, a Curators’ Distinguished Professor Emeritus in the Department of Biology at the University of Missouri–St. Louis, passed away on June 7, one day after his 83rd birthday.
Ricklefs built one of the most significant careers in modern ecology over 51 years split between the faculty at the University of Pennsylvania and UMSL. He advanced our understanding of ecology, speciation and diversification, and the forces that shape biodiversity across the globe. He was honored with the Sewall Wright Award in 2005 by the
American Society of Naturalists. He was elected as a member of the National Academy of Sciences in 2009 for his pioneering research on evolutionary ecology and island biogeography. In 2015, he was awarded the Ramon Margalef Prize in Ecology, an award designed to recognize an exceptional scientific career.
Despite these impressive honors, Ricklefs measured his success not in honors but in the people he trained. He was once quoted as saying his students were the greatest reward of his work, and he mentored 47 PhD students throughout his career. He could be exacting, but he was lauded by all for his generosity with his time and ideas.
Ricklefs also was a warm and thoughtful colleague.
“I worked in the same area of evolutionary ecology, so I understand the impact of his scientific accomplishments deeply, but the thing that I think needs to be emphasized is that he was the nicest person I have ever known,” said Patricia Parker, a professor emerita who worked alongside Ricklefs for nearly two decades in the Department of Biology. “Never once did I hear him say a negative word about a colleague, and I spoke with him every day that we were both present on campus. My students remember finding him in my office when they would arrive for a meeting, and he would politely excuse himself. He found me every day just to catch up.”
Ricklefs studied biology at Stanford University and then completed his PhD at Penn, where he studied avian growth and development, earning his degree in 1967. He did a postdoctoral fellowship at the Smithsonian Tropical Research Institute before returning to Penn, where he was a faculty member for 27 years.
He arrived at UMSL in 1995, serving as Curators' Distinguished Professor of Biology for more than two decades before his retirement in 2019. He cared deeply about UMSL and especially its students. After winning the Margalef Prize, he and his wife, Dr. Susanne Renner, established an endowment known as the Ramon Margalef Biology Lecture fund, which continues to bring leading scientists in ecology to campus to interact with biology students. He authored widely used and influential academic textbooks, including Ecology and The Economy of Nature, which further introduced the discipline to students worldwide.
Ricklefs had a motto that he had inherited from his father: suave in modo, fortiter in re – gentle in manner, firm in deed. The UMSL community is better for his decades of contributions and advocacy. The Department of Biology extends its condolences to his family, his colleagues and collaborators, and the many scientists he mentored. His legacy endures in all of them.
Memorial donations can be made in honor of Ricklefs to the Margalef Symposium Fund through the UMSL Department of Biology or to the Whitney R. Harris World Ecology Center.
A memorial service is planned to celebrate his life and legacy on Monday, Aug. 17 from 3-5 p.m. at the Blanche M. Touhill Performing Arts Center on the UMSL Campus.
Find more information about the event and share your memories of Ricklefs.
Read an online obituary from Mongabay:
https://news.mongabay.com/2026/06/robert-ricklefs-ecologist-who-helped-generations-understand-nature-has-died-at-83/
Read an UMSL Daily story about Ricklefs’ retirement in 2019:
https://blogs.umsl.edu/news/2019/08/28/ricklefs-retirement/
Read a profile of Ricklefs from PNAS in 2012:
https://www.pnas.org/doi/10.1073/pnas.1213178109
