More than 100 students have conducted research under my guidance and the majority of these accompanied me to professional scientific meetings, primarily those of the Animal Behavior Society, the four principal U.S. and Canada ornithological societies and the Pennsylvania Academy of Science. The specific areas of study from 1979 to present are: (1) on campus, the gross anatomy and histology of the avian digestive tract that addresses structure, function and evolution and various aspects of museum research in our Acopian Center for Ornithology, (2) on- and off-campus field studies that address the behavior of birds, primarily those associated with bird-human interactions.     

More than 70 peer-reviewed scientific publications report the results of my research; among them are the following considered significant (with the exception of the Armenian books, co-authors of multi-authored works are Muhlenberg College students). The final three are recent invited keynote addresses. 

• Klem Jr., D, PG Saenger, and BP Brogle 2024. Evidence, consequences, and angle of strike of bird–window collisions. The Wilson Journal of Ornithology 136(1):113-119
• Klem Jr., D and PG Saenger 2013. Evaluating the Effectiveness of Select Visual Signals to Prevent Bird-window Collisions. The Wilson Journal of Ornithology 125(2):406-411
• Klem, D., Jr., C.R. Brancato, J. F. Catalano, and F. Kuzmin. 1982. Gross Morphology and General Histology of the Esophagus, Ingluvies and Proventriculus of the House Sparrow (Passer domesticus). Proceedings of Pennsylvania Academy of Science 56:141-146.
• Klem, D., Jr. and B. S. Hillegass, and D. A. Peters. Raptors Killing Raptors, Wilson Bulletin 97:230-231. (1985).
• Klem, D., Jr. Bird-window Collisions, Wilson Bulletin 101:606-620. (1989).
• Klem, D., Jr. Collisions between Birds and Windows: Mortality and Prevention, Journal of Field Ornithology 61:120-128. (1990).
• Adamian, M. S. and D. Klem, Jr. A Field Guide to Birds of Armenia, American University of Armenia, xxiii+223 pp. (1997).
• Adamian, M. S. and D. Klem, Jr., Handbook of the Birds of Armenia, American University of Armenia, 649 pp. (2000).
• Klem, D., Jr., D. C. Keck, K. L. Marty, A. J. Miller Ball, E. E. Niciu, and C. T. Platt. Effects of Window Angling, Feeder Placement and Scavengers on Avian Mortality at Plate Glass, Wilson Bulletin 116:69-73. (2004).
• Veltri, C. J. and D. Klem, Jr. Comparison of Fatal Bird Injuries from Collisions with Towers and Windows, Journal of Field Ornithology 76:127-133. (2005).
• Klem, D., Jr. Preventing Bird-Window Collisions. Wilson Journal of Ornithology 121:314-321. (2009).
• Klem, D., Jr. Bird-Window Collisions: A Critical Animal Welfare and Conservation Issue, Journal of Applied Animal Welfare Science 18:S11-S17; doi:10.1080/10888705.2015.1075832. (2015).
• Klem, D., Jr. Bird Strike Injury and Death at Sheet Glass Worldwide: A Critical Animal Welfare and Compassionate Conservation Issue, Compassionate Conservation International Conference, University of British Columbia, BC, Canada, (July 2015).
• Klem, D., Jr. How Big a Deal are Bird-Window Strikes and What Can Be Done?, 4th Urban Wildlife Workshop, Life in the City, 81st North American Wildlife and Natural Resource Conference, Grand Wyndam Hotel, Pittsburgh, PA, (March 2016).
• Klem, D., Jr. History, Fundamentals and Contemporary Needs of Bird-Window Collision Study, Powdermill Nature Reserve, Carnegie Museum of Art and Natural History, Rector, PA (April 2017).