Since his retirement in 1997, Curator Emeritus Duellman has been active in divisional business and in research. He scanned more than 11,000 color slides of amphibians and reptiles. These images and others added from various sources are documented in the KUDA (Kansas University Digital Archives), Most of the images are documented with the KU catalogue number of the specimen in the collection. One of the forthcoming additions to the Specify database will be associated of images with specimens. Duellman also catalogued more than 1600 tape recordings on reels; these have been digitized by the Fonteca Zoológica in the Museo Nacional de Historia Natural in Madrid, and the original tapes are now in the Library of Natural Sounds. Other curatorial responsibilities have been the updating of some taxa in the database.
In the past decade or so, Duellman’s research activities have focused on collaborating with various colleagues in South America, principally on hemiphractid frogs. However, most of his time has been devoted to five books—a revised edition of Hylid Frogs of Middle America (2001), a synthesis of his work in Amazonia Peru—Cusco Amazónico, the Lives of Amphibians and Reptiles in an Amazonian Rainforest (2005), and with Edgar Lehr a systematic and biogeographic analysis of a large portion of the Peruvian frog fauna—Terrestrial Breeding Frogs (Strabomantidae) in Peru (2008). Early in 2014 he completed many years of research on hemiphractid frogs and submitted the lengthy manuscript, Marsupial Frogs and Their Allies, to the Johns Hopkins University Press. Lastly, he is writing a history of herpetology at the University of Kansas.