Robert Ricklefs

Robert Eric Ricklefs (June 6, 1943 – June 7, 2026) was an American ornithologist and ecologist. He was the Curators' Professor of Biology at the University of Missouri, St. Louis from 1996 until August 2019.

Early life and education Born on June 6, 1943, he grew up near Monterey, California, where his interest in biology was fostered by a teacher. He graduated with a Bachelor of Science from Stanford University in 1963 and a Ph.D. from the University of Pennsylvania in 1967. His doctoral advisor was originally Robert H. MacArthur (prior to his move to Princeton University), but he finished his dissertation under W. John Smith. During his PhD, he studied avian growth and development, which he continued for much of his career. He completed a year as a postdoctoral fellow at the Smithsonian Tropical Research Institute in Panama before taking up a faculty position at the University of Pennsylvania. He was the 1982 recipient of the American Ornithologists' Union's William Brewster Memorial Award, the union's most prestigious award given annually for an exceptional body of work on birds of the Western Hemisphere. In 2003, he received the Pacific Seabird Group's Lifetime Achievement Award for his work on growth and development in seabirds. He was awarded the 2003 Margaret Morse Nice Medal by the Wilson Ornithological Society. He was the 2006 recipient of the Cooper Ornithological Society’s Loye and Alden Miller Research Award, which is given in recognition of lifetime achievement in ornithological research.

Research During his career, he has made major contributions to the island biogeography, including testing E. O. Wilson's Taxon Cycle Concept, His most-cited scientific paper examined ecological communities. Recent work has sought to rescale the concept of an ecological community. He has made major contributions to life-history theory of birds, avian growth and development, tropical ecology, and avian disease research. His original method for avian growth rate estimation He has also published The Economy of Nature , Avian Growth and Development: Evolution Within the Altricial-precocial Spectrum and Aging, A Natural History.

Career Assistant Professor, Department of Biology, University of Pennsylvania, 1968-1972 Associate Professor, Department of Biology, University of Pennsylvania, 1972-1978 Professor, Department of Biology, University of Pennsylvania, 1978-1995 Curators’ Professor, Department of Biology, University of Missouri-St. Louis, 1995-2019.

Personal life and death Ricklefs was married to the botanist Susanne Renner.

Awards 1982: William Brewster Memorial Award, American Ornithologists' Union 2006: Love and Alden Miller Research Award, Cooper Ornithological Society 2010: Honorary doctorate from Aarhus University, Denmark 2010: Honorary doctorate from the University of Burgundy, France 2010: Honorary doctorate from the Catholic University of Louvain (Belgium) 2011: Alfred Wallace Award, The International Biogeography Society 2015: Ramon Margalef Prize in Ecology 2017: Honorary Lifetime Membership Award, American Society of Naturalists 2018: Honorary degree from the University of Chicago